VisualStyleRenderer Class
Definition
Important
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Provides methods for drawing and getting information about a VisualStyleElement. This class cannot be inherited.
public ref class VisualStyleRenderer sealedpublic sealed class VisualStyleRenderertype VisualStyleRenderer = classPublic NotInheritable Class VisualStyleRenderer- Inheritance
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VisualStyleRenderer
Examples
The following code example uses the VisualStyleRenderer class to implement a custom control that simulates some of the basic UI of a window, including dragging with the title bar, resizing with the sizing handle, and closing. This example uses several VisualStyleElement objects that represent standard parts of a window, including the elements exposed by the VisualStyleElement.Window.Caption, VisualStyleElement.Window.CloseButton, and VisualStyleElement.Status.Gripper classes.
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
#using <System.dll>
using namespace System;
using namespace System::Text;
using namespace System::Drawing;
using namespace System::Drawing::Drawing2D;
using namespace System::Collections::Generic;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;
namespace VisualStyleRendererSample
{
public ref class WindowSimulation : public Control
{
private:
Dictionary<String^, VisualStyleElement^>^ windowElements;
Dictionary<String^, Rectangle>^ elementRectangles;
VisualStyleRenderer^ renderer;
Point closeButtonOffset;
System::Drawing::Size gripperSize;
System::Drawing::Size closeButtonSize;
bool isResizing;
bool isMoving;
bool isClosing;
int captionHeight;
int frameThickness;
int statusHeight;
Point originalClick;
Point resizeOffset;
public:
WindowSimulation() : Control()
{
statusHeight = 22;
windowElements = gcnew Dictionary<String^, VisualStyleElement^>();
elementRectangles = gcnew Dictionary<String^, Rectangle>();
this->Location = Point(50, 50);
this->Size = System::Drawing::Size(350, 300);
this->BackColor = Color::Azure;
this->DoubleBuffered = true;
this->MinimumSize = System::Drawing::Size(300, 200);
this->Font = SystemFonts::CaptionFont;
this->Text = "Simulated Window";
// Insert the VisualStyleElement objects into the Dictionary.
windowElements->Add("windowCaption",
VisualStyleElement::Window::Caption::Active);
windowElements->Add("windowBottom",
VisualStyleElement::Window::FrameBottom::Active);
windowElements->Add("windowLeft",
VisualStyleElement::Window::FrameLeft::Active);
windowElements->Add("windowRight",
VisualStyleElement::Window::FrameRight::Active);
windowElements->Add("windowClose",
VisualStyleElement::Window::CloseButton::Normal);
windowElements->Add("statusBar",
VisualStyleElement::Status::Bar::Normal);
windowElements->Add("statusGripper",
VisualStyleElement::Status::Gripper::Normal);
// Get the sizes and location offsets for the window parts
// as specified by the visual style, and then use this
// information to calcualate the rectangles for each part.
GetPartDetails();
CalculateRectangles();
this->MouseDown +=
gcnew MouseEventHandler(this,
&WindowSimulation::ImitationWindow_MouseDown);
this->MouseUp +=
gcnew MouseEventHandler(this,
&WindowSimulation::ImitationWindow_MouseUp);
this->MouseMove +=
gcnew MouseEventHandler(this,
&WindowSimulation::ImitationWindow_MouseMove);
}
// Get the sizes and offsets for the window parts as specified
// by the visual style.
private:
void GetPartDetails()
{
// Do nothing further if visual styles are not enabled.
if (!Application::RenderWithVisualStyles)
{
return;
}
Graphics^ g = this->CreateGraphics();
// Get the size and offset of the close button.
if (SetRenderer(windowElements["windowClose"]))
{
closeButtonSize =
renderer->GetPartSize(g, ThemeSizeType::True);
closeButtonOffset =
renderer->GetPoint(PointProperty::Offset);
}
// Get the height of the window caption.
if (SetRenderer(windowElements["windowCaption"]))
{
captionHeight = renderer->GetPartSize(g,
ThemeSizeType::True).Height;
}
// Get the thickness of the left, bottom,
// and right window frame.
if (SetRenderer(windowElements["windowLeft"]))
{
frameThickness = renderer->GetPartSize(g,
ThemeSizeType::True).Width;
}
// Get the size of the resizing gripper.
if (SetRenderer(windowElements["statusGripper"]))
{
gripperSize = renderer->GetPartSize(g,
ThemeSizeType::True);
}
}
// Use the part metrics to determine the current size
// of the rectangles for all of the window parts.
private:
void CalculateRectangles()
{
int heightMinusFrame =
ClientRectangle.Height - frameThickness;
// Calculate the window frame rectangles and add them
// to the Dictionary of rectangles.
elementRectangles["windowCaption"] = Rectangle(0, 0,
ClientRectangle.Width, captionHeight);
elementRectangles["windowBottom"] = Rectangle(0,
heightMinusFrame, ClientRectangle.Width, frameThickness);
elementRectangles["windowLeft"] = Rectangle(0, captionHeight,
frameThickness, heightMinusFrame - captionHeight);
elementRectangles["windowRight"] = Rectangle(
ClientRectangle.Width - frameThickness, captionHeight,
frameThickness, heightMinusFrame - captionHeight);
// Calculate the window button rectangle and add it
// to the Dictionary of rectangles.
elementRectangles["windowClose"] =
Rectangle(ClientRectangle.Right +
closeButtonOffset.X - closeButtonSize.Width - frameThickness, closeButtonOffset.Y,
closeButtonSize.Width, closeButtonSize.Height);
// Calculate the status bar rectangles and add them
// to the Dictionary of rectangles.
elementRectangles["statusBar"] =
Rectangle(frameThickness,
heightMinusFrame - statusHeight,
ClientRectangle.Width - (2 * frameThickness),
statusHeight);
elementRectangles["statusGripper"] =
Rectangle(ClientRectangle.Right -
gripperSize.Width - frameThickness,
heightMinusFrame - gripperSize.Height,
gripperSize.Width, gripperSize.Height);
}
protected:
virtual void OnPaint(PaintEventArgs^ e) override
{
__super::OnPaint(e);
// Ensure that visual styles are supported.
if (!Application::RenderWithVisualStyles)
{
this->Text = "Visual styles are not enabled.";
TextRenderer::DrawText(e->Graphics, this->Text,
this->Font, this->Location, this->ForeColor);
return;
}
// Set the clip region to define the curved corners
// of the caption.
SetClipRegion();
// Draw each part of the window.
for each(KeyValuePair<String^, VisualStyleElement^>^ entry
in windowElements)
{
if (SetRenderer(entry->Value))
{
renderer->DrawBackground(e->Graphics,
elementRectangles[entry->Key]);
}
}
// Draw the caption text.
TextRenderer::DrawText(e->Graphics, this->Text, this->Font,
elementRectangles["windowCaption"], Color::White,
TextFormatFlags::VerticalCenter |
TextFormatFlags::HorizontalCenter);
}
private:
// Initiate dragging, resizing, or closing the imitation window.
void ImitationWindow_MouseDown(Object^ sender, MouseEventArgs^ e)
{
// The user clicked the close button.
if (elementRectangles["windowClose"].Contains(e->Location))
{
windowElements["windowClose"] =
VisualStyleElement::Window::CloseButton::Pressed;
isClosing = true;
}
// The user clicked the status grip.
else if (elementRectangles["statusGripper"].Contains(e->Location))
{
isResizing = true;
this->Cursor = Cursors::SizeNWSE;
resizeOffset.X = this->Right - this->Left - e->X;
resizeOffset.Y = this->Bottom - this->Top - e->Y;
}
// The user clicked the window caption.
else if (elementRectangles["windowCaption"].Contains(e->Location))
{
isMoving = true;
originalClick.X = e->X;
originalClick.Y = e->Y;
}
Invalidate();
}
// Stop any current resizing or moving actions.
void ImitationWindow_MouseUp(Object^ sender, MouseEventArgs^ e)
{
// Stop moving the location of the window rectangles.
if (isMoving)
{
isMoving = false;
}
// Change the cursor back to the default if the user
// stops resizing.
else if (isResizing)
{
isResizing = false;
}
// Close the application if the user clicks the
// close button.
else if (elementRectangles["windowClose"].Contains(e->Location)
&& isClosing)
{
Application::Exit();
}
}
// Handle resizing or moving actions.
void ImitationWindow_MouseMove(Object^ sender,
MouseEventArgs^ e)
{
// The left mouse button is down.
if ((::MouseButtons::Left & e->Button) == ::MouseButtons::Left)
{
// Calculate the new control size if the user is
// dragging the resizing grip.
if (isResizing)
{
this->Width = e->X + resizeOffset.X;
this->Height = e->Y + resizeOffset.Y;
CalculateRectangles();
}
// Calculate the new location of the control if the
// user is dragging the window caption.
else if (isMoving)
{
int XChange = this->Location.X + (e->X - originalClick.X);
int YChange = this->Location.Y + (e->Y - originalClick.Y);
this->Location = Point(XChange, YChange);
}
// Cancel the closing action if the user clicked
// and held down on the close button, and has dragged
// the pointer outside the button.
else if (!elementRectangles["windowClose"].Contains(
e->Location) && isClosing)
{
isClosing = false;
windowElements["windowClose"] =
VisualStyleElement::Window::CloseButton::Normal;
}
}
// The left mouse button is not down.
else
{
// Paint the close button hot if the cursor is on it.
Rectangle^ closeRectangle =
elementRectangles["windowClose"];
if (closeRectangle->Contains(e->Location))
{
windowElements["windowClose"] =
VisualStyleElement::Window::CloseButton::Hot;
}
else
{
windowElements["windowClose"] =
VisualStyleElement::Window::CloseButton::Normal;
}
// Use a resizing cursor if the cursor is on the
// status grip.
Rectangle^ gripRectangle = elementRectangles["statusGripper"];
if (gripRectangle->Contains(e->Location))
{
this->Cursor = Cursors::SizeNWSE;
}
else
{
this->Cursor = Cursors::Default;
}
}
Invalidate();
}
// Calculate and set the clipping region for the control
// so that the corners of the title bar are rounded.
private:
void SetClipRegion()
{
if (!Application::RenderWithVisualStyles)
{
return;
}
Graphics^ g = this->CreateGraphics();
// Get the current region for the window caption.
if (SetRenderer(windowElements["windowCaption"]))
{
System::Drawing::Region^ clipRegion =
renderer->GetBackgroundRegion(g,
elementRectangles["windowCaption"]);
// Get the client rectangle, but exclude the region
// of the window caption.
int height = (int)clipRegion->GetBounds(g).Height;
System::Drawing::Rectangle nonCaptionRect = Rectangle(
ClientRectangle.X, ClientRectangle.Y + height,
ClientRectangle.Width, ClientRectangle.Height - height);
// Add the rectangle to the caption region, and
// make this region the form's clipping region.
clipRegion->Union(nonCaptionRect);
this->Region = clipRegion;
}
}
// Set the VisualStyleRenderer to a new element.
private:
bool SetRenderer(VisualStyleElement^ element)
{
if (!VisualStyleRenderer::IsElementDefined(element))
{
return false;
}
if (renderer == nullptr)
{
renderer = gcnew VisualStyleRenderer(element);
}
else
{
renderer->SetParameters(element);
}
return true;
}
};
public ref class Form1 : public Form
{
public:
Form1() : Form()
{
this->Size = System::Drawing::Size(800, 600);
this->Location = Point(20, 20);
this->BackColor = Color::DarkGray;
WindowSimulation^ ws = gcnew WindowSimulation();
Controls->Add(ws);
}
};
}
[STAThread]
int main()
{
Application::EnableVisualStyles();
Application::Run(gcnew VisualStyleRendererSample::Form1());
}
using System;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
namespace VisualStyleRendererSample
{
class Form1 : Form
{
public Form1()
: base()
{
this.Size = new Size(800, 600);
this.Location = new Point(20, 20);
this.BackColor = Color.DarkGray;
WindowSimulation Window1 = new WindowSimulation();
Controls.Add(Window1);
}
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.Run(new Form1());
}
}
public class WindowSimulation : Control
{
private Dictionary<string, VisualStyleElement> windowElements =
new Dictionary<string, VisualStyleElement>();
private Dictionary<string, Rectangle> elementRectangles =
new Dictionary<string, Rectangle>();
private VisualStyleRenderer renderer = null;
private Point closeButtonOffset;
private Size gripperSize;
private Size closeButtonSize;
private bool isResizing = false;
private bool isMoving = false;
private bool isClosing = false;
private int captionHeight;
private int frameThickness;
private int statusHeight = 22;
private Point originalClick = new Point();
private Point resizeOffset = new Point();
public WindowSimulation()
: base()
{
this.Location = new Point(50, 50);
this.Size = new Size(350, 300);
this.BackColor = Color.Azure;
this.DoubleBuffered = true;
this.MinimumSize = new Size(300, 200);
this.Font = SystemFonts.CaptionFont;
this.Text = "Simulated Window";
// Insert the VisualStyleElement objects into the Dictionary.
windowElements.Add("windowCaption",
VisualStyleElement.Window.Caption.Active);
windowElements.Add("windowBottom",
VisualStyleElement.Window.FrameBottom.Active);
windowElements.Add("windowLeft",
VisualStyleElement.Window.FrameLeft.Active);
windowElements.Add("windowRight",
VisualStyleElement.Window.FrameRight.Active);
windowElements.Add("windowClose",
VisualStyleElement.Window.CloseButton.Normal);
windowElements.Add("statusBar",
VisualStyleElement.Status.Bar.Normal);
windowElements.Add("statusGripper",
VisualStyleElement.Status.Gripper.Normal);
// Get the sizes and location offsets for the window parts
// as specified by the visual style, and then use this
// information to calcualate the rectangles for each part.
GetPartDetails();
CalculateRectangles();
this.MouseDown +=
new MouseEventHandler(ImitationWindow_MouseDown);
this.MouseUp +=
new MouseEventHandler(ImitationWindow_MouseUp);
this.MouseMove +=
new MouseEventHandler(ImitationWindow_MouseMove);
}
// Get the sizes and offsets for the window parts as specified
// by the visual style.
private void GetPartDetails()
{
// Do nothing further if visual styles are not enabled.
if (!Application.RenderWithVisualStyles)
{
return;
}
using (Graphics g = this.CreateGraphics())
{
// Get the size and offset of the close button.
if (SetRenderer(windowElements["windowClose"]))
{
closeButtonSize =
renderer.GetPartSize(g, ThemeSizeType.True);
closeButtonOffset =
renderer.GetPoint(PointProperty.Offset);
}
// Get the height of the window caption.
if (SetRenderer(windowElements["windowCaption"]))
{
captionHeight = renderer.GetPartSize(g,
ThemeSizeType.True).Height;
}
// Get the thickness of the left, bottom,
// and right window frame.
if (SetRenderer(windowElements["windowLeft"]))
{
frameThickness = renderer.GetPartSize(g,
ThemeSizeType.True).Width;
}
// Get the size of the resizing gripper.
if (SetRenderer(windowElements["statusGripper"]))
{
gripperSize = renderer.GetPartSize(g,
ThemeSizeType.True);
}
}
}
// Use the part metrics to determine the current size
// of the rectangles for all of the window parts.
private void CalculateRectangles()
{
int heightMinusFrame =
ClientRectangle.Height - frameThickness;
// Calculate the window frame rectangles and add them
// to the Dictionary of rectangles.
elementRectangles["windowCaption"] =
new Rectangle(0, 0,
ClientRectangle.Width, captionHeight);
elementRectangles["windowBottom"] =
new Rectangle(0, heightMinusFrame,
ClientRectangle.Width, frameThickness);
elementRectangles["windowLeft"] =
new Rectangle(0, captionHeight, frameThickness,
heightMinusFrame - captionHeight);
elementRectangles["windowRight"] =
new Rectangle(ClientRectangle.Width - frameThickness,
captionHeight, frameThickness,
heightMinusFrame - captionHeight);
// Calculate the window button rectangle and add it
// to the Dictionary of rectangles.
elementRectangles["windowClose"] =
new Rectangle(ClientRectangle.Right +
closeButtonOffset.X - closeButtonSize.Width - frameThickness, closeButtonOffset.Y,
closeButtonSize.Width, closeButtonSize.Height);
// Calculate the status bar rectangles and add them
// to the Dictionary of rectangles.
elementRectangles["statusBar"] =
new Rectangle(frameThickness,
heightMinusFrame - statusHeight,
ClientRectangle.Width - (2 * frameThickness),
statusHeight);
elementRectangles["statusGripper"] =
new Rectangle(ClientRectangle.Right -
gripperSize.Width - frameThickness,
heightMinusFrame - gripperSize.Height,
gripperSize.Width, gripperSize.Height);
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
// Ensure that visual styles are supported.
if (!Application.RenderWithVisualStyles)
{
this.Text = "Visual styles are not enabled.";
TextRenderer.DrawText(e.Graphics, this.Text,
this.Font, this.Location, this.ForeColor);
return;
}
// Set the clip region to define the curved corners
// of the caption.
SetClipRegion();
// Draw each part of the window.
foreach (KeyValuePair<string, VisualStyleElement> entry
in windowElements)
{
if (SetRenderer(entry.Value))
{
renderer.DrawBackground(e.Graphics,
elementRectangles[entry.Key]);
}
}
// Draw the caption text.
TextRenderer.DrawText(e.Graphics, this.Text, this.Font,
elementRectangles["windowCaption"], Color.White,
TextFormatFlags.VerticalCenter |
TextFormatFlags.HorizontalCenter);
}
// Initiate dragging, resizing, or closing the imitation window.
void ImitationWindow_MouseDown(object sender, MouseEventArgs e)
{
// The user clicked the close button.
if (elementRectangles["windowClose"].Contains(e.Location))
{
windowElements["windowClose"] =
VisualStyleElement.Window.CloseButton.Pressed;
isClosing = true;
}
// The user clicked the status grip.
else if (elementRectangles["statusGripper"].
Contains(e.Location))
{
isResizing = true;
this.Cursor = Cursors.SizeNWSE;
resizeOffset.X = this.Right - this.Left - e.X;
resizeOffset.Y = this.Bottom - this.Top - e.Y;
}
// The user clicked the window caption.
else if (elementRectangles["windowCaption"].
Contains(e.Location))
{
isMoving = true;
originalClick.X = e.X;
originalClick.Y = e.Y;
}
Invalidate();
}
// Stop any current resizing or moving actions.
void ImitationWindow_MouseUp(object sender, MouseEventArgs e)
{
// Stop moving the location of the window rectangles.
if (isMoving)
{
isMoving = false;
}
// Change the cursor back to the default if the user
// stops resizing.
else if (isResizing)
{
isResizing = false;
}
// Close the application if the user clicks the
// close button.
else if (elementRectangles["windowClose"].
Contains(e.Location) && isClosing)
{
Application.Exit();
}
}
// Handle resizing or moving actions.
void ImitationWindow_MouseMove(object sender,
MouseEventArgs e)
{
// The left mouse button is down.
if ((MouseButtons.Left & e.Button) == MouseButtons.Left)
{
// Calculate the new control size if the user is
// dragging the resizing grip.
if (isResizing)
{
this.Width = e.X + resizeOffset.X;
this.Height = e.Y + resizeOffset.Y;
CalculateRectangles();
}
// Calculate the new location of the control if the
// user is dragging the window caption.
else if (isMoving)
{
int XChange = this.Location.X +
(e.X - originalClick.X);
int YChange = this.Location.Y +
(e.Y - originalClick.Y);
this.Location = new Point(XChange, YChange);
}
// Cancel the closing action if the user clicked
// and held down on the close button, and has dragged
// the pointer outside the button.
else if (!elementRectangles["windowClose"].
Contains(e.Location) && isClosing)
{
isClosing = false;
windowElements["windowClose"] =
VisualStyleElement.Window.CloseButton.Normal;
}
}
// The left mouse button is not down.
else
{
// Paint the close button hot if the cursor is on it.
Rectangle closeRectangle =
elementRectangles["windowClose"];
windowElements["windowClose"] =
closeRectangle.Contains(e.Location) ?
VisualStyleElement.Window.CloseButton.Hot :
VisualStyleElement.Window.CloseButton.Normal;
// Use a resizing cursor if the cursor is on the
// status grip.
Rectangle gripRectangle =
elementRectangles["statusGripper"];
this.Cursor = gripRectangle.Contains(e.Location) ?
Cursors.SizeNWSE : Cursors.Default;
}
Invalidate();
}
// Calculate and set the clipping region for the control
// so that the corners of the title bar are rounded.
private void SetClipRegion()
{
if (!Application.RenderWithVisualStyles)
{
return;
}
using (Graphics g = this.CreateGraphics())
{
// Get the current region for the window caption.
if (SetRenderer(windowElements["windowCaption"]))
{
Region clipRegion = renderer.GetBackgroundRegion(
g, elementRectangles["windowCaption"]);
// Get the client rectangle, but exclude the region
// of the window caption.
int height = (int)clipRegion.GetBounds(g).Height;
Rectangle nonCaptionRect = new Rectangle(
ClientRectangle.X,
ClientRectangle.Y + height,
ClientRectangle.Width,
ClientRectangle.Height - height);
// Add the rectangle to the caption region, and
// make this region the form's clipping region.
clipRegion.Union(nonCaptionRect);
this.Region = clipRegion;
}
}
}
// Set the VisualStyleRenderer to a new element.
private bool SetRenderer(VisualStyleElement element)
{
if (!VisualStyleRenderer.IsElementDefined(element))
{
return false;
}
if (renderer == null)
{
renderer = new VisualStyleRenderer(element);
}
else
{
renderer.SetParameters(element);
}
return true;
}
}
}
Imports System.Text
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Collections.Generic
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles
Namespace VisualStyleRendererSample
Class Form1
Inherits Form
Public Sub New()
With Me
.Size = New Size(800, 600)
.Location = New Point(20, 20)
.BackColor = Color.DarkGray
End With
Dim Window1 As New ImitationWindow()
Controls.Add(Window1)
End Sub
<STAThread()> _
Shared Sub Main()
Application.EnableVisualStyles()
Application.Run(New Form1())
End Sub
End Class
Public Class ImitationWindow
Inherits Control
Private windowElements As _
New Dictionary(Of String, VisualStyleElement)
Private elementRectangles As _
New Dictionary(Of String, Rectangle)
Private renderer As VisualStyleRenderer = Nothing
Private closeButtonOffset As Point
Private gripperSize As Size
Private closeButtonSize As Size
Private isResizing As Boolean = False
Private isMoving As Boolean = False
Private isClosing As Boolean = False
Private captionHeight As Integer
Private frameThickness As Integer
Private statusHeight As Integer = 22
Private originalClick As New Point()
Private resizeOffset As New Point()
Public Sub New()
With Me
.Location = New Point(50, 50)
.Size = New Size(350, 300)
.BackColor = Color.Azure
.DoubleBuffered = True
.MinimumSize = New Size(300, 200)
.Font = SystemFonts.CaptionFont
.Text = "Imitation Window"
End With
' Create a collection of VisualStyleElement objects.
With windowElements
.Add("windowCaption", _
VisualStyleElement.Window.Caption.Active)
.Add("windowBottom", _
VisualStyleElement.Window.FrameBottom.Active)
.Add("windowLeft", _
VisualStyleElement.Window.FrameLeft.Active)
.Add("windowRight", _
VisualStyleElement.Window.FrameRight.Active)
.Add("windowClose", _
VisualStyleElement.Window.CloseButton.Normal)
.Add("statusBar", _
VisualStyleElement.Status.Bar.Normal)
.Add("statusGripper", _
VisualStyleElement.Status.Gripper.Normal)
End With
' Get the sizes and location offsets for the window parts
' as specified by the visual style, and then use this
' information to calcualate the rectangles for each part.
GetPartDetails()
CalculateRectangles()
End Sub
' Get the sizes and offsets for the window parts as specified
' by the visual style.
Private Sub GetPartDetails()
' Do nothing further if visual styles are not enabled.
If Not Application.RenderWithVisualStyles Then
Return
End If
Using g As Graphics = Me.CreateGraphics()
' Get the size and offset of the close button.
If SetRenderer(windowElements("windowClose")) Then
closeButtonSize = _
renderer.GetPartSize(g, ThemeSizeType.True)
closeButtonOffset = _
renderer.GetPoint(PointProperty.Offset)
End If
' Get the height of the window caption.
If SetRenderer(windowElements("windowCaption")) Then
captionHeight = renderer.GetPartSize(g, _
ThemeSizeType.True).Height
End If
' Get the thickness of the left, bottom, and right
' window frame.
If SetRenderer(windowElements("windowLeft")) Then
frameThickness = renderer.GetPartSize(g, _
ThemeSizeType.True).Width
End If
' Get the size of the resizing gripper.
If SetRenderer(windowElements("statusGripper")) Then
gripperSize = renderer.GetPartSize(g, _
ThemeSizeType.True)
End If
End Using
End Sub
' Use the part metrics to determine the current size of the
' rectangles for all of the window parts.
Private Sub CalculateRectangles()
Dim heightMinusFrame As Integer = _
ClientRectangle.Height - frameThickness
' Calculate the window frame rectangles and add them
' to the Dictionary of rectangles.
elementRectangles("windowCaption") = _
New Rectangle(0, 0, ClientRectangle.Width, _
captionHeight)
elementRectangles("windowBottom") = _
New Rectangle(0, heightMinusFrame, _
ClientRectangle.Width, frameThickness)
elementRectangles("windowLeft") = _
New Rectangle(0, captionHeight, frameThickness, _
heightMinusFrame - captionHeight)
elementRectangles("windowRight") = _
New Rectangle(ClientRectangle.Width - frameThickness, _
captionHeight, frameThickness, _
heightMinusFrame - captionHeight)
' Calculate the window button rectangle and add it
' to the Dictionary of rectangles.
elementRectangles("windowClose") = _
New Rectangle(ClientRectangle.Right + _
closeButtonOffset.X - closeButtonSize.Width - frameThickness, closeButtonOffset.Y, _
closeButtonSize.Width, closeButtonSize.Height)
' Calculate the status bar rectangles and add them
' to the Dictionary of rectangles.
elementRectangles("statusBar") = _
New Rectangle(frameThickness, _
heightMinusFrame - statusHeight, _
ClientRectangle.Width - 2 * frameThickness, _
statusHeight)
elementRectangles("statusGripper") = _
New Rectangle(ClientRectangle.Right - _
gripperSize.Width - frameThickness, _
heightMinusFrame - gripperSize.Height, _
gripperSize.Width, gripperSize.Height)
End Sub
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
MyBase.OnPaint(e)
' Ensure that visual styles are supported.
If Not Application.RenderWithVisualStyles Then
Me.Text = "Visual styles are not enabled."
TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
Me.Location, Me.ForeColor)
Return
End If
' Set the clip region to define the curved corners of
' the caption.
SetClipRegion()
' Draw each part of the window.
Dim entry As KeyValuePair(Of String, VisualStyleElement)
For Each entry In windowElements
If SetRenderer(entry.Value) Then
renderer.DrawBackground(e.Graphics, _
elementRectangles(entry.Key))
End If
Next entry
' Draw the caption text.
TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
elementRectangles("windowCaption"), Color.White, _
TextFormatFlags.VerticalCenter Or _
TextFormatFlags.HorizontalCenter)
End Sub
' Initiate dragging, resizing, or closing the imitation window.
Private Sub ImitationWindow_MouseDown(ByVal sender As Object, _
ByVal e As MouseEventArgs) Handles Me.MouseDown
' The user clicked the close button.
If elementRectangles("windowClose"). _
Contains(e.Location) Then
windowElements("windowClose") = _
VisualStyleElement.Window.CloseButton.Pressed
isClosing = True
' The user clicked the status grip.
ElseIf elementRectangles("statusGripper"). _
Contains(e.Location) Then
isResizing = True
Me.Cursor = Cursors.SizeNWSE
resizeOffset.X = Me.Right - Me.Left - e.X
resizeOffset.Y = Me.Bottom - Me.Top - e.Y
' The user clicked the window caption.
ElseIf elementRectangles("windowCaption"). _
Contains(e.Location) Then
isMoving = True
originalClick.X = e.X
originalClick.Y = e.Y
End If
Invalidate()
End Sub
' Stop any current resizing or moving actions.
Private Sub ImitationWindow_MouseUp(ByVal sender As Object, _
ByVal e As MouseEventArgs) Handles Me.MouseUp
' Stop moving the location of the window rectangles.
If isMoving Then
isMoving = False
' Change the cursor back to the default if the
' user stops resizing.
ElseIf isResizing Then
isResizing = False
' Close the application if the user clicks the
' close button.
ElseIf elementRectangles("windowClose"). _
Contains(e.Location) And isClosing Then
Application.Exit()
End If
End Sub
' Handle resizing or moving actions.
Private Sub ImitationWindow_MouseMove(ByVal sender As Object, _
ByVal e As MouseEventArgs) Handles Me.MouseMove
' The left mouse button is down.
If (MouseButtons.Left And e.Button) = _
MouseButtons.Left Then
' Calculate the new control size if the user is
' dragging the resizing grip.
If isResizing Then
Me.Width = e.X + resizeOffset.X
Me.Height = e.Y + resizeOffset.Y
CalculateRectangles()
' Calculate the new location of the control if
' the user is dragging the window caption.
ElseIf isMoving Then
Dim XChange As Integer = Me.Location.X + _
(e.X - originalClick.X)
Dim YChange As Integer = Me.Location.Y + _
(e.Y - originalClick.Y)
Me.Location = New Point(XChange, YChange)
' Cancel the closing action if the user clicked and
' held down on the close button, and has dragged the
' pointer outside the button.
ElseIf Not elementRectangles("windowClose"). _
Contains(e.Location) And isClosing Then
isClosing = False
windowElements("windowClose") = _
VisualStyleElement.Window.CloseButton.Normal
End If
' The left mouse button is not down.
Else
' Paint the close button hot if the cursor is on it.
If elementRectangles("windowClose"). _
Contains(e.Location) Then
windowElements("windowClose") = _
VisualStyleElement.Window.CloseButton.Hot
Else
windowElements("windowClose") = _
VisualStyleElement.Window.CloseButton.Normal
End If
' Use a resizing cursor if the cursor is on the
' status grip.
If elementRectangles("statusGripper"). _
Contains(e.Location) Then
Me.Cursor = Cursors.SizeNWSE
Else
Me.Cursor = Cursors.Default
End If
End If
Invalidate()
End Sub
' Calculate and set the clipping region for the control
' so that the corners of the title bar are rounded.
Private Sub SetClipRegion()
If Not Application.RenderWithVisualStyles Then
Return
End If
Using g As Graphics = Me.CreateGraphics()
' Get the current region for the window caption.
If SetRenderer(windowElements("windowCaption")) Then
Dim clipRegion As Region = _
renderer.GetBackgroundRegion(g, _
elementRectangles("windowCaption"))
' Get the client rectangle, but exclude the
' region of the window caption.
Dim height As Integer = _
CInt(clipRegion.GetBounds(g).Height)
Dim nonCaptionRect As _
New Rectangle(ClientRectangle.X, _
ClientRectangle.Y + height, _
ClientRectangle.Width, _
ClientRectangle.Height - height)
' Add the rectangle to the caption region, and
' make this region the form's clipping region.
clipRegion.Union(nonCaptionRect)
Me.Region = clipRegion
End If
End Using
End Sub
' Set the VisualStyleRenderer to a new element.
Private Function SetRenderer(ByVal element As _
VisualStyleElement) As Boolean
If Not VisualStyleRenderer.IsElementDefined(element) Then
Return False
End If
If renderer Is Nothing Then
renderer = New VisualStyleRenderer(element)
Else
renderer.SetParameters(element)
End If
Return True
End Function
End Class
End Namespace
Remarks
The System.Windows.Forms.VisualStyles namespace exposes VisualStyleElement objects that represent all of the controls and user interface (UI) elements that are supported by visual styles. To draw or get information about a particular element, you must set a VisualStyleRenderer to the element you are interested in. A VisualStyleRenderer is automatically set to a specified VisualStyleElement in the VisualStyleRenderer constructor, but you can also set an existing VisualStyleRenderer to a different element by calling the SetParameters method.
To draw an element, use the DrawBackground method. The VisualStyleRenderer class also includes methods, such as GetColor and GetEnumValue, that provide information about how an element is defined by the current visual style.
The VisualStyleRenderer constructor and many of the VisualStyleRenderer methods throw exceptions unless visual styles are enabled in the operating system and visual styles are applied to the client area of application windows. To check for these conditions, use the static IsSupported property.
The VisualStyleRenderer class wraps the functionality of the visual styles (UxTheme) API from the Windows Shell portion of the Windows Platform SDK.
Constructors
| VisualStyleRenderer(String, Int32, Int32) |
Initializes a new instance of the VisualStyleRenderer class using the given class, part, and state values. |
| VisualStyleRenderer(VisualStyleElement) |
Initializes a new instance of the VisualStyleRenderer class using the given VisualStyleElement. |
Properties
| Class |
Gets the class name of the current visual style element. |
| Handle |
Gets a unique identifier for the current class of visual style elements. |
| IsSupported |
Gets a value specifying whether the operating system is using visual styles to draw controls. |
| LastHResult |
Gets the last error code returned by the native visual styles (UxTheme) API methods encapsulated by the VisualStyleRenderer class. |
| Part |
Gets the part of the current visual style element. |
| State |
Gets the state of the current visual style element. |
Methods
| DrawBackground(IDeviceContext, Rectangle, Rectangle) |
Draws the background image of the current visual style element within the specified bounding rectangle and clipped to the specified clipping rectangle. |
| DrawBackground(IDeviceContext, Rectangle) |
Draws the background image of the current visual style element within the specified bounding rectangle. |
| DrawEdge(IDeviceContext, Rectangle, Edges, EdgeStyle, EdgeEffects) |
Draws one or more edges of the specified bounding rectangle. |
| DrawImage(Graphics, Rectangle, Image) |
Draws the specified image within the specified bounds. |
| DrawImage(Graphics, Rectangle, ImageList, Int32) |
Draws the image from the specified ImageList within the specified bounds. |
| DrawParentBackground(IDeviceContext, Rectangle, Control) |
Draws the background of a control's parent in the specified area. |
| DrawText(IDeviceContext, Rectangle, String, Boolean, TextFormatFlags) |
Draws text in the specified bounding rectangle with the option of displaying disabled text and applying other text formatting. |
| DrawText(IDeviceContext, Rectangle, String, Boolean) |
Draws text in the specified bounds with the option of displaying disabled text. |
| DrawText(IDeviceContext, Rectangle, String) |
Draws text in the specified bounds using default formatting. |
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| GetBackgroundContentRectangle(IDeviceContext, Rectangle) |
Returns the content area for the background of the current visual style element. |
| GetBackgroundExtent(IDeviceContext, Rectangle) |
Returns the entire background area for the current visual style element. |
| GetBackgroundRegion(IDeviceContext, Rectangle) |
Returns the region for the background of the current visual style element. |
| GetBoolean(BooleanProperty) |
Returns the value of the specified Boolean property for the current visual style element. |
| GetColor(ColorProperty) |
Returns the value of the specified color property for the current visual style element. |
| GetEnumValue(EnumProperty) |
Returns the value of the specified enumerated type property for the current visual style element. |
| GetFilename(FilenameProperty) |
Returns the value of the specified file name property for the current visual style element. |
| GetFont(IDeviceContext, FontProperty) |
Returns the value of the specified font property for the current visual style element. |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetInteger(IntegerProperty) |
Returns the value of the specified integer property for the current visual style element. |
| GetMargins(IDeviceContext, MarginProperty) |
Returns the value of the specified margins property for the current visual style element. |
| GetPartSize(IDeviceContext, Rectangle, ThemeSizeType) |
Returns the value of the specified size property of the current visual style part using the specified drawing bounds. |
| GetPartSize(IDeviceContext, ThemeSizeType) |
Returns the value of the specified size property of the current visual style part. |
| GetPoint(PointProperty) |
Returns the value of the specified point property for the current visual style element. |
| GetString(StringProperty) |
Returns the value of the specified string property for the current visual style element. |
| GetTextExtent(IDeviceContext, Rectangle, String, TextFormatFlags) |
Returns the size and location of the specified string when drawn with the font of the current visual style element within the specified initial bounding rectangle. |
| GetTextExtent(IDeviceContext, String, TextFormatFlags) |
Returns the size and location of the specified string when drawn with the font of the current visual style element. |
| GetTextMetrics(IDeviceContext) |
Retrieves information about the font specified by the current visual style element. |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| HitTestBackground(Graphics, Rectangle, Region, Point, HitTestOptions) |
Returns a hit test code indicating whether the point is contained in the background of the current visual style element and within the specified bounds. |
| HitTestBackground(IDeviceContext, Rectangle, IntPtr, Point, HitTestOptions) |
Returns a hit test code indicating whether the point is contained in the background of the current visual style element and within the specified region. |
| HitTestBackground(IDeviceContext, Rectangle, Point, HitTestOptions) |
Returns a hit test code indicating whether a point is contained in the background of the current visual style element. |
| IsBackgroundPartiallyTransparent() |
Indicates whether the background of the current visual style element has any semitransparent or alpha-blended pieces. |
| IsElementDefined(VisualStyleElement) |
Determines whether the specified visual style element is defined by the current visual style. |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| SetParameters(String, Int32, Int32) |
Sets this VisualStyleRenderer to the visual style element represented by the specified class, part, and state values. |
| SetParameters(VisualStyleElement) |
Sets this VisualStyleRenderer to the visual style element represented by the specified VisualStyleElement. |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Applies to
See also
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