TextBoxRenderer 类

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

提供用于呈现具有视觉样式的文本框控件的方法。 此类不能被继承。

public ref class TextBoxRenderer sealed

public ref class TextBoxRenderer abstract sealed

public sealed class TextBoxRenderer

public static class TextBoxRenderer

type TextBoxRenderer = class

Public NotInheritable Class TextBoxRenderer

Public Class TextBoxRenderer

继承

Object

TextBoxRenderer

示例

下面的代码示例演示如何创建自定义控件，该控件使用 DrawTextBox 该方法绘制文本框。 该控件还允许用户选择要应用于文本框文本的值 TextFormatFlags 之一。

#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::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;

namespace TextBoxRendererSample
{
    public ref class CustomTextBox : public Control
    {
    private:
        TextFormatFlags textFlags;
        ComboBox^ textFormatFlagsComboBox;
        Rectangle textBorder;
        Rectangle textRectangle;
        StringBuilder^ textMeasurements;

    public:
        CustomTextBox():Control()
        {
            textFlags = TextFormatFlags::Default;
            textFormatFlagsComboBox = gcnew ComboBox();

            textMeasurements = gcnew StringBuilder();

            this->Location = Point(10, 10);
            this->Size = System::Drawing::Size(300, 200);
            this->Font = SystemFonts::IconTitleFont;
            this->Text = "This is a long sentence that will exceed " +
                "the text box bounds";

            textBorder.Location = Point(10, 10);
            textBorder.Size = System::Drawing::Size(200, 50);
            textRectangle.Location = Point(textBorder.X + 2,
                textBorder.Y + 2);
            textRectangle.Size =  System::Drawing::Size(textBorder.Size.Width - 4,
                textBorder.Height - 4);

            textFormatFlagsComboBox->Location = Point(10, 100);
            textFormatFlagsComboBox->Size = System::Drawing::Size(150, 20);
            textFormatFlagsComboBox->SelectedIndexChanged +=
                gcnew EventHandler(this, 
                &CustomTextBox::textFormatFlagsComboBox_SelectedIndexChanged);

            // Populate the combo box with the TextFormatFlags value names.
            for each (String^ name in Enum::GetNames(TextFormatFlags::typeid))
            {
                textFormatFlagsComboBox->Items->Add(name);
            }

            textFormatFlagsComboBox->SelectedIndex = 0;
            this->Controls->Add(textFormatFlagsComboBox);
        }

        // Use DrawText with the current TextFormatFlags.

    protected:
        virtual void OnPaint(PaintEventArgs^ e) override
        {
            __super::OnPaint(e);

            if (TextBoxRenderer::IsSupported)
            {
                TextBoxRenderer::DrawTextBox(e->Graphics, textBorder, this->Text,
                    this->Font, textRectangle, textFlags, TextBoxState::Normal);

                this->Parent->Text = "CustomTextBox Enabled";
            }
            else
            {
                this->Parent->Text = "CustomTextBox Disabled";
            }
        }

        // Assign the combo box selection to the display text.
    private:
        void textFormatFlagsComboBox_SelectedIndexChanged(
            Object^ sender, EventArgs^ e)
        {
            this->textFlags = (TextFormatFlags)Enum::Parse(
                TextFormatFlags::typeid,
                (String^)textFormatFlagsComboBox->Items[
                    textFormatFlagsComboBox->SelectedIndex]);

                    Invalidate();
        }
    };

    public ref class Form1 : public Form
    {
    public:
        Form1()
        {
            __super::Form();
            this->Size = System::Drawing::Size(350, 200);
            CustomTextBox^ textBox1 = gcnew CustomTextBox();
            Controls->Add(textBox1);
        }
    };
}

using namespace TextBoxRendererSample;

[STAThread]
int main()
{     
    // The call to EnableVisualStyles below does not affect whether 
    // TextBoxRenderer draws the text box; as long as visual styles 
    // are enabled by the operating system, TextBoxRenderer will 
    // draw the text box.
    Application::EnableVisualStyles();
    Application::Run(gcnew Form1());
}

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

namespace TextBoxRendererSample
{
    class Form1 : Form
    {
        public Form1()
            : base()
        {
            this.Size = new Size(350, 200);
            CustomTextBox TextBox1 = new CustomTextBox();
            Controls.Add(TextBox1);
        }

        [STAThread]
        static void Main()
        {
            // The call to EnableVisualStyles below does not affect whether 
            // TextBoxRenderer draws the text box; as long as visual styles 
            // are enabled by the operating system, TextBoxRenderer will 
            // draw the text box.
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }
    }

    public class CustomTextBox : Control
    {
        private TextFormatFlags textFlags = TextFormatFlags.Default;
        ComboBox comboBox1 = new ComboBox();
        Rectangle textBorder = new Rectangle();
        Rectangle textRectangle = new Rectangle();
        StringBuilder textMeasurements = new StringBuilder();

        public CustomTextBox()
            : base()
        {
            this.Location = new Point(10, 10);
            this.Size = new Size(300, 200);
            this.Font = SystemFonts.IconTitleFont;
            this.Text = "This is a long sentence that will exceed " +
                "the text box bounds";

            textBorder.Location = new Point(10, 10);
            textBorder.Size = new Size(200, 50);
            textRectangle.Location = new Point(textBorder.X + 2,
                textBorder.Y + 2);
            textRectangle.Size = new Size(textBorder.Size.Width - 4,
                textBorder.Height - 4);

            comboBox1.Location = new Point(10, 100);
            comboBox1.Size = new Size(150, 20);
            comboBox1.SelectedIndexChanged +=
                new EventHandler(comboBox1_SelectedIndexChanged);

            // Populate the combo box with the TextFormatFlags value names.
            foreach (string name in Enum.GetNames(typeof(TextFormatFlags)))
            {
                comboBox1.Items.Add(name);
            }

            comboBox1.SelectedIndex = 0;
            this.Controls.Add(comboBox1);
        }

        // Use DrawText with the current TextFormatFlags.
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            if (TextBoxRenderer.IsSupported)
            {
                TextBoxRenderer.DrawTextBox(e.Graphics, textBorder, this.Text,
                    this.Font, textRectangle, textFlags, TextBoxState.Normal);

                this.Parent.Text = "CustomTextBox Enabled";
            }
            else
            {
                this.Parent.Text = "CustomTextBox Disabled";
            }
        }

        // Assign the combo box selection to the display text.
        void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.textFlags = (TextFormatFlags)Enum.Parse(
                typeof(TextFormatFlags),
                (string)comboBox1.Items[comboBox1.SelectedIndex]);
            Invalidate();
        }
    }
}

Imports System.Text
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles

Namespace TextBoxRendererSample

    Class Form1
        Inherits Form

        Public Sub New()
            Me.Size = New Size(350, 200)
            Dim TextBox1 As New CustomTextBox()
            Controls.Add(TextBox1)
        End Sub

        <STAThread()> _
        Shared Sub Main()
            ' The call to EnableVisualStyles below does not affect whether 
            ' TextBoxRenderer draws the text box; as long as visual styles 
            ' are enabled by the operating system, TextBoxRenderer will 
            ' draw the text box.
            Application.EnableVisualStyles()
            Application.Run(New Form1())
        End Sub
    End Class

    Public Class CustomTextBox
        Inherits Control

        Private textFlags As TextFormatFlags = TextFormatFlags.Default
        Private WithEvents comboBox1 As New ComboBox()
        Private textBorder As New Rectangle()
        Private textRectangle As New Rectangle()
        Private textMeasurements As New StringBuilder()

        Public Sub New()

            With Me
                .Location = New Point(10, 10)
                .Size = New Size(300, 200)
                .Font = SystemFonts.IconTitleFont
                .Text = "This is a long sentence that will exceed " + _
                    "the text box bounds"
            End With

            textBorder.Location = New Point(10, 10)
            textBorder.Size = New Size(200, 50)
            textRectangle.Location = New Point(textBorder.X + 2, _
                textBorder.Y + 2)
            textRectangle.Size = New Size(textBorder.Size.Width - 4, _
                textBorder.Height - 4)

            comboBox1.Location = New Point(10, 100)
            comboBox1.Size = New Size(150, 20)

            ' Populate the combo box with the TextFormatFlags value names.
            Dim name As String
            For Each name In [Enum].GetNames(GetType(TextFormatFlags))
                comboBox1.Items.Add(name)
            Next name

            comboBox1.SelectedIndex = 0
            Me.Controls.Add(comboBox1)
        End Sub

        ' Use DrawText with the current TextFormatFlags.
        Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
            MyBase.OnPaint(e)

            If TextBoxRenderer.IsSupported Then
                TextBoxRenderer.DrawTextBox(e.Graphics, textBorder, Me.Text, _
                    Me.Font, textRectangle, textFlags, TextBoxState.Normal)
                Me.Parent.Text = "CustomTextBox Enabled"
            Else
                Me.Parent.Text = "CustomTextBox Disabled"
            End If
        End Sub

        ' Assign the combo box selection to the display text.
        Private Sub comboBox1_SelectedIndexChanged(ByVal sender As Object, _
            ByVal e As EventArgs) Handles comboBox1.SelectedIndexChanged

            Me.textFlags = CType([Enum].Parse(GetType(TextFormatFlags), _
                CStr(comboBox1.Items(comboBox1.SelectedIndex))), _
                TextFormatFlags)
            Invalidate()
        End Sub

    End Class
End Namespace

注解

该 TextBoxRenderer 类提供了一组 static 方法，可用于使用操作系统的当前视觉样式呈现文本框控件。 呈现控件是指绘制控件的用户界面。 如果要绘制应具有当前视觉样式外观的自定义控件，这非常有用。 若要绘制文本框，请使用其中 DrawTextBox 一种方法。 这些方法提供各种选项，例如应用文本格式或指定文本边界。

如果在操作系统中启用了视觉样式，并且视觉样式应用于应用程序窗口的工作区， DrawTextBox 则会使用当前视觉样式绘制文本框。 否则， DrawTextBox 将引发一个 InvalidOperationException。 若要确定是否可以使用此类的成员，可以检查 IsSupported 属性值。

此类包装 System.Windows.Forms.VisualStyles.VisualStyleRenderer 设置为类的 System.Windows.Forms.VisualStyles.VisualStyleElement.TextBox.TextEdit 元素之一的功能。 有关详细信息，请参阅使用视觉样式呈现控件。

属性

IsSupported

获取一个值，该值指示 TextBoxRenderer 类是否可用于绘制具有视觉样式的文本框。

方法

DrawTextBox(Graphics, Rectangle, String, Font, Rectangle, TextBoxState)	绘制具有指定的状态和边界以及指定的文本和文本边界的文本框控件。
DrawTextBox(Graphics, Rectangle, String, Font, Rectangle, TextFormatFlags, TextBoxState)	绘制具有指定的状态和边界以及指定的文本、文本边界和文本格式的文本框控件。
DrawTextBox(Graphics, Rectangle, String, Font, TextBoxState)	绘制具有指定的状态和边界以及指定的文本的文本框控件。
DrawTextBox(Graphics, Rectangle, String, Font, TextFormatFlags, TextBoxState)	绘制具有指定的状态和边界以及指定的文本和文本格式的文本框控件。
DrawTextBox(Graphics, Rectangle, TextBoxState)	绘制具有指定状态和边界的文本框控件。

另请参阅

• VisualStyleRenderer
• VisualStyleElement