ToolStripRenderer 类
定义
重要
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处理 ToolStrip 对象的绘制功能。
public ref class ToolStripRenderer abstractpublic abstract class ToolStripRenderertype ToolStripRenderer = classPublic MustInherit Class ToolStripRenderer- 继承
-
ToolStripRenderer
- 派生
示例
以下代码示例演示了如何实现一个自定义 ToolStripRenderer 类。 类 GridStripRenderer 自定义控件外观的 GridStrip 三个方面： GridStrip 边框、 ToolStripButton 边框和 ToolStripButton 图像。 有关完整代码列表，请参阅 如何：实现自定义 ToolStripRenderer。
// This class implements a custom ToolStripRenderer for the
// GridStrip control. It customizes three aspects of the
// GridStrip control's appearance: GridStrip border,
// ToolStripButton border, and ToolStripButton image.
internal class GridStripRenderer : ToolStripRenderer
{
// The style of the empty cell's text.
private static StringFormat style = new StringFormat();
// The thickness (width or height) of a
// ToolStripButton control's border.
static int borderThickness = 2;
// The main bitmap that is the source for the
// subimagesthat are assigned to individual
// ToolStripButton controls.
private Bitmap bmp = null;
// The brush that paints the background of
// the GridStrip control.
private Brush backgroundBrush = null;
// This is the static constructor. It initializes the
// StringFormat for drawing the text in the empty cell.
static GridStripRenderer()
{
style.Alignment = StringAlignment.Center;
style.LineAlignment = StringAlignment.Center;
}
// This method initializes the GridStripRenderer by
// creating the image that is used as the source for
// the individual button images.
protected override void Initialize(ToolStrip ts)
{
base.Initialize(ts);
this.InitializeBitmap(ts);
}
// This method initializes an individual ToolStripButton
// control. It copies a subimage from the GridStripRenderer's
// main image, according to the position and size of
// the ToolStripButton.
protected override void InitializeItem(ToolStripItem item)
{
base.InitializeItem(item);
GridStrip gs = item.Owner as GridStrip;
// The empty cell does not receive a subimage.
if ((item is ToolStripButton) &&
(item != gs.EmptyCell))
{
// Copy the subimage from the appropriate
// part of the main image.
Bitmap subImage = bmp.Clone(
item.Bounds,
PixelFormat.Undefined);
// Assign the subimage to the ToolStripButton
// control's Image property.
item.Image = subImage;
}
}
// This utility method creates the main image that
// is the source for the subimages of the individual
// ToolStripButton controls.
private void InitializeBitmap(ToolStrip toolStrip)
{
// Create the main bitmap, into which the image is drawn.
this.bmp = new Bitmap(
toolStrip.Size.Width,
toolStrip.Size.Height);
// Draw a fancy pattern. This could be any image or drawing.
using (Graphics g = Graphics.FromImage(bmp))
{
// Draw smoothed lines.
g.SmoothingMode = SmoothingMode.AntiAlias;
// Draw the image. In this case, it is
// a number of concentric ellipses.
for (int i = 0; i < toolStrip.Size.Width; i += 8)
{
g.DrawEllipse(Pens.Blue, 0, 0, i, i);
}
}
}
// This method draws a border around the GridStrip control.
protected override void OnRenderToolStripBorder(
ToolStripRenderEventArgs e)
{
base.OnRenderToolStripBorder(e);
ControlPaint.DrawFocusRectangle(
e.Graphics,
e.AffectedBounds,
SystemColors.ControlDarkDark,
SystemColors.ControlDarkDark);
}
// This method renders the GridStrip control's background.
protected override void OnRenderToolStripBackground(
ToolStripRenderEventArgs e)
{
base.OnRenderToolStripBackground(e);
// This late initialization is a workaround. The gradient
// depends on the bounds of the GridStrip control. The bounds
// are dependent on the layout engine, which hasn't fully
// performed layout by the time the Initialize method runs.
if (this.backgroundBrush == null)
{
this.backgroundBrush = new LinearGradientBrush(
e.ToolStrip.ClientRectangle,
SystemColors.ControlLightLight,
SystemColors.ControlDark,
90,
true);
}
// Paint the GridStrip control's background.
e.Graphics.FillRectangle(
this.backgroundBrush,
e.AffectedBounds);
}
// This method draws a border around the button's image. If the background
// to be rendered belongs to the empty cell, a string is drawn. Otherwise,
// a border is drawn at the edges of the button.
protected override void OnRenderButtonBackground(
ToolStripItemRenderEventArgs e)
{
base.OnRenderButtonBackground(e);
// Define some local variables for convenience.
Graphics g = e.Graphics;
GridStrip gs = e.ToolStrip as GridStrip;
ToolStripButton gsb = e.Item as ToolStripButton;
// Calculate the rectangle around which the border is painted.
Rectangle imageRectangle = new Rectangle(
borderThickness,
borderThickness,
e.Item.Width - 2 * borderThickness,
e.Item.Height - 2 * borderThickness);
// If rendering the empty cell background, draw an
// explanatory string, centered in the ToolStripButton.
if (gsb == gs.EmptyCell)
{
e.Graphics.DrawString(
"Drag to here",
gsb.Font,
SystemBrushes.ControlDarkDark,
imageRectangle, style);
}
else
{
// If the button can be a drag source, paint its border red.
// otherwise, paint its border a dark color.
Brush b = gs.IsValidDragSource(gsb) ? b =
Brushes.Red : SystemBrushes.ControlDarkDark;
// Draw the top segment of the border.
Rectangle borderSegment = new Rectangle(
0,
0,
e.Item.Width,
imageRectangle.Top);
g.FillRectangle(b, borderSegment);
// Draw the right segment.
borderSegment = new Rectangle(
imageRectangle.Right,
0,
e.Item.Bounds.Right - imageRectangle.Right,
imageRectangle.Bottom);
g.FillRectangle(b, borderSegment);
// Draw the left segment.
borderSegment = new Rectangle(
0,
0,
imageRectangle.Left,
e.Item.Height);
g.FillRectangle(b, borderSegment);
// Draw the bottom segment.
borderSegment = new Rectangle(
0,
imageRectangle.Bottom,
e.Item.Width,
e.Item.Bounds.Bottom - imageRectangle.Bottom);
g.FillRectangle(b, borderSegment);
}
}
}
' This class implements a custom ToolStripRenderer for the
' GridStrip control. It customizes three aspects of the
' GridStrip control's appearance: GridStrip border,
' ToolStripButton border, and ToolStripButton image.
Friend Class GridStripRenderer
Inherits ToolStripRenderer
' The style of the empty cell's text.
Private Shared style As New StringFormat()
' The thickness (width or height) of a
' ToolStripButton control's border.
Private Shared borderThickness As Integer = 2
' The main bitmap that is the source for the
' subimagesthat are assigned to individual
' ToolStripButton controls.
Private bmp As Bitmap = Nothing
' The brush that paints the background of
' the GridStrip control.
Private backgroundBrush As Brush = Nothing
' This is the static constructor. It initializes the
' StringFormat for drawing the text in the empty cell.
Shared Sub New()
style.Alignment = StringAlignment.Center
style.LineAlignment = StringAlignment.Center
End Sub
' This method initializes the GridStripRenderer by
' creating the image that is used as the source for
' the individual button images.
Protected Overrides Sub Initialize(ts As ToolStrip)
MyBase.Initialize(ts)
Me.InitializeBitmap(ts)
End Sub
' This method initializes an individual ToolStripButton
' control. It copies a subimage from the GridStripRenderer's
' main image, according to the position and size of
' the ToolStripButton.
Protected Overrides Sub InitializeItem(item As ToolStripItem)
MyBase.InitializeItem(item)
Dim gs As GridStrip = item.Owner
' The empty cell does not receive a subimage.
If ((TypeOf (item) Is ToolStripButton) And _
(item IsNot gs.EmptyCell)) Then
' Copy the subimage from the appropriate
' part of the main image.
Dim subImage As Bitmap = bmp.Clone(item.Bounds, PixelFormat.Undefined)
' Assign the subimage to the ToolStripButton
' control's Image property.
item.Image = subImage
End If
End Sub
' This utility method creates the main image that
' is the source for the subimages of the individual
' ToolStripButton controls.
Private Sub InitializeBitmap(toolStrip As ToolStrip)
' Create the main bitmap, into which the image is drawn.
Me.bmp = New Bitmap(toolStrip.Size.Width, toolStrip.Size.Height)
' Draw a fancy pattern. This could be any image or drawing.
Dim g As Graphics = Graphics.FromImage(bmp)
Try
' Draw smoothed lines.
g.SmoothingMode = SmoothingMode.AntiAlias
' Draw the image. In this case, it is
' a number of concentric ellipses.
Dim i As Integer
For i = 0 To toolStrip.Size.Width - 8 Step 8
g.DrawEllipse(Pens.Blue, 0, 0, i, i)
Next i
Finally
g.Dispose()
End Try
End Sub
' This method draws a border around the GridStrip control.
Protected Overrides Sub OnRenderToolStripBorder(e As ToolStripRenderEventArgs)
MyBase.OnRenderToolStripBorder(e)
ControlPaint.DrawFocusRectangle(e.Graphics, e.AffectedBounds, SystemColors.ControlDarkDark, SystemColors.ControlDarkDark)
End Sub
' This method renders the GridStrip control's background.
Protected Overrides Sub OnRenderToolStripBackground(e As ToolStripRenderEventArgs)
MyBase.OnRenderToolStripBackground(e)
' This late initialization is a workaround. The gradient
' depends on the bounds of the GridStrip control. The bounds
' are dependent on the layout engine, which hasn't fully
' performed layout by the time the Initialize method runs.
If Me.backgroundBrush Is Nothing Then
Me.backgroundBrush = New LinearGradientBrush(e.ToolStrip.ClientRectangle, SystemColors.ControlLightLight, SystemColors.ControlDark, 90, True)
End If
' Paint the GridStrip control's background.
e.Graphics.FillRectangle(Me.backgroundBrush, e.AffectedBounds)
End Sub
' This method draws a border around the button's image. If the background
' to be rendered belongs to the empty cell, a string is drawn. Otherwise,
' a border is drawn at the edges of the button.
Protected Overrides Sub OnRenderButtonBackground(e As ToolStripItemRenderEventArgs)
MyBase.OnRenderButtonBackground(e)
' Define some local variables for convenience.
Dim g As Graphics = e.Graphics
Dim gs As GridStrip = e.ToolStrip
Dim gsb As ToolStripButton = e.Item
' Calculate the rectangle around which the border is painted.
Dim imageRectangle As New Rectangle(borderThickness, borderThickness, e.Item.Width - 2 * borderThickness, e.Item.Height - 2 * borderThickness)
' If rendering the empty cell background, draw an
' explanatory string, centered in the ToolStripButton.
If gsb Is gs.EmptyCell Then
e.Graphics.DrawString("Drag to here", gsb.Font, SystemBrushes.ControlDarkDark, imageRectangle, style)
Else
' If the button can be a drag source, paint its border red.
' otherwise, paint its border a dark color.
Dim b As Brush = IIf(gs.IsValidDragSource(gsb), Brushes.Red, SystemBrushes.ControlDarkDark)
' Draw the top segment of the border.
Dim borderSegment As New Rectangle(0, 0, e.Item.Width, imageRectangle.Top)
g.FillRectangle(b, borderSegment)
' Draw the right segment.
borderSegment = New Rectangle(imageRectangle.Right, 0, e.Item.Bounds.Right - imageRectangle.Right, imageRectangle.Bottom)
g.FillRectangle(b, borderSegment)
' Draw the left segment.
borderSegment = New Rectangle(0, 0, imageRectangle.Left, e.Item.Height)
g.FillRectangle(b, borderSegment)
' Draw the bottom segment.
borderSegment = New Rectangle(0, imageRectangle.Bottom, e.Item.Width, e.Item.Bounds.Bottom - imageRectangle.Bottom)
g.FillRectangle(b, borderSegment)
End If
End Sub
End Class
注解
ToolStripRenderer使用 类将特定样式或主题应用于 ToolStrip。 将 属性设置为ToolStrip.Renderer继承自 ToolStripRenderer的对象，而不是自定义绘制 ToolStripToolStripItem 及其包含的对象。 指定的 ToolStripRenderer 绘图将应用于 ToolStrip，以及它包含的项。
可以通过多种方式在 ToolStrip 控件中执行自定义绘制。 与其他 Windows 窗体控件一样，ToolStrip 和ToolStripItem 两者都具有可重写的 OnPaint 方法和 Paint 事件。 与常规绘制一样，坐标系相对于控件的工作区：也就是说，控件的左上角为 0, 0。
ToolStripItem 的 Paint 事件和 OnPaint 方法的行为方式与其他控件绘制事件一样。
类 ToolStripRenderer 具有可替代的方法，用于绘制 的背景、项背景、项图像、项箭头、项文本和边框 ToolStrip。 这些方法的事件参数会公开多个属性，如矩形、颜色和文本格式，你可以根据需要进行调整。
若要仅调整项绘制方式的几个方面，通常会重写 ToolStripRenderer。
如果要编写一个新项并且要控制绘制的所有方面，请重写 OnPaint 方法。 在 OnPaint 内部，可以使用来自 ToolStripRenderer 的方法。
默认情况下，ToolStrip 会进行双缓冲（利用 OptimizedDoubleBuffer 设置）。
构造函数
| ToolStripRenderer() |
初始化 ToolStripRenderer 类的新实例。 |
字段
| Offset2X |
获取或设置两次沿 x 轴偏移的偏移乘数。 |
| Offset2Y |
获取或设置两次沿 y 轴偏移的偏移乘数。 |
方法
事件
| RenderArrow |
在呈现 ToolStripItem 上的箭头时发生。 |
| RenderButtonBackground |
当呈现 ToolStripButton 的背景时发生。 |
| RenderDropDownButtonBackground |
当呈现 ToolStripDropDownButton 的背景时发生。 |
| RenderGrip |
当呈现 ToolStrip 的移动手柄时发生。 |
| RenderImageMargin |
绘制图像与图像容器之间的边距。 |
| RenderItemBackground |
当呈现 ToolStripItem 的背景时发生。 |
| RenderItemCheck |
当呈现选定 ToolStripItem 的图像时发生。 |
| RenderItemImage |
当呈现 ToolStripItem 的图像时发生。 |
| RenderItemText |
当呈现 ToolStripItem 的文本时发生。 |
| RenderLabelBackground |
当呈现 ToolStripLabel 的背景时发生。 |
| RenderMenuItemBackground |
当呈现 ToolStripMenuItem 的背景时发生。 |
| RenderOverflowButtonBackground |
在呈现溢出按钮的背景时发生。 |
| RenderSeparator |
当呈现 ToolStripSeparator 时发生。 |
| RenderSplitButtonBackground |
当呈现 ToolStripSplitButton 的背景时发生。 |
| RenderStatusStripSizingGrip |
当显示样式更改时发生。 |
| RenderToolStripBackground |
当呈现 ToolStrip 的背景时发生。 |
| RenderToolStripBorder |
当呈现 ToolStrip 的边框时发生。 |
| RenderToolStripContentPanelBackground |
绘制 ToolStripContentPanel 的背景。 |
| RenderToolStripPanelBackground |
绘制 ToolStripPanel 的背景。 |
| RenderToolStripStatusLabelBackground |
绘制 ToolStripStatusLabel 的背景。 |
