Windows 窗体 RichTextBox 控件的常见用途是使用字体选项或段落样式等属性设置文本格式。 应用程序可能需要跟踪文本格式的任何更改,以便显示工具栏,就像许多字处理应用程序一样。
响应格式属性的变化
根据属性的值,在 SelectionChanged 事件处理程序中编写代码以执行适当的作。 以下示例根据属性的值 SelectionBullet 更改工具栏按钮的外观。 只有在控件中移动插入点后,工具栏按钮才会更新。
下面的示例假定窗体包含一个 RichTextBox 控件和一个 ToolBar 包含工具栏按钮的控件。 有关工具栏和工具栏按钮的详细信息,请参阅 How to: Add Buttons to a ToolBar Control.
' The following code assumes the existence of a toolbar control ' with at least one toolbar button. Private Sub RichTextBox1_SelectionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles RichTextBox1.SelectionChanged If RichTextBox1.SelectionBullet = True Then ' Bullet button on toolbar should appear pressed ToolBarButton1.Pushed = True Else ' Bullet button on toolbar should appear unpressed ToolBarButton1.Pushed = False End If End Sub
// The following code assumes the existence of a toolbar control // with at least one toolbar button. private void richTextBox1_SelectionChanged(object sender, System.EventArgs e) { if (richTextBox1.SelectionBullet == true) { // Bullet button on toolbar should appear pressed toolBarButton1.Pushed = true; } else { // Bullet button on toolbar should appear unpressed toolBarButton1.Pushed = false; } }
// The following code assumes the existence of a toolbar control // with at least one toolbar button. private: System::Void richTextBox1_SelectionChanged( System::Object ^ sender, System::EventArgs ^ e) { if (richTextBox1->SelectionBullet == true) { // Bullet button on toolbar should appear pressed toolBarButton1->Pushed = true; } else { // Bullet button on toolbar should appear unpressed toolBarButton1->Pushed = false; } }