C#文本选中及ContextMenuStrip菜单使用

‘文本框选中显示
‘TextBox1.SelectAll()选择所有文本
1 Private Sub TextBox1_MouseClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseClick
2         Dim start As Integer = TextBox1.SelectionStart  ‘光标开始位置索引
3         Dim SelectValue As String = TextBox1.SelectedText ‘选中文本的值
4         Dim length As Integer = TextBox1.SelectedText.Trim.Length ‘选中文本的长度
5         If length > 0 Then
6             TextBox1.Select(start, length) ‘选中文本从光标到指定长度
7         End If
8     End Sub

‘选中文本后右键弹出菜单栏
 1 Private Sub TextBox1_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
 2 
 3         If TextBox1.SelectedText.Trim.Length > 0 Then
 4             If e.Button = Windows.Forms.MouseButtons.Right Then
 5                 TextBox1.Enabled = False
 6                 TextBox1.ContextMenuStrip = ContextMenuStrip1
 7                 TextBox1.Enabled = True
 8             End If
 9         End If
10     End Sub