章鱼哥—VB.NET RichTextBox.AllowDrop属性的实例

来源：互联网发布：淘宝企业账号怎么注册编辑：程序博客网时间：2024/05/17 01:58

这篇文章讲述allowDrop属性的另一种用法，即接受文字，读者可以借鉴下，该文为转载文章地址：http://www.lob.cn/sl/control/431.shtml

RichTextBox.AllowDrop属性的实例

下面的代码示例演示如何使用 ListBox 控件（包含要放入 RichTextBox 控件的项）来执行拖放操作。窗体的构造函数将AllowDrop 属性设置为 true 以使拖放操作能够在 RichTextBox 中进行。该示例使用ListBox 的 MouseDown 事件通过调用 DoDragDrop 方法来启动拖动操作。该示例使用 DragEnter 事件来确定拖放到RichTextBox 中的项是否为有效的数据类型。DragDrop 事件将被拖动的项实际放在 RichTextBox 控件中RichTextBox 内的当前光标位置。该示例要求 DragDrop 和 DragEnter 事件已连接到此示例中定义的事件处理程序。

Public Sub New()
MyBase.New()
'This call is required by the Windows Form Designer.
InitializeComponent()
richTextBox1.AllowDrop = True
End Sub
Private Sub listBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles listBox1.MouseDown
' Determines which item was selected.
Dim lb As ListBox = CType(sender, ListBox)
Dim pt As New Point(e.X, e.Y)
'Retrieve the item at the specified location within the ListBox.
Dim index As Integer = lb.IndexFromPoint(pt)
' Starts a drag-and-drop operation.
If index >= 0 Then
' Retrieve the selected item text to drag into the RichTextBox.
lb.DoDragDrop(lb.Items(index).ToString(), DragDropEffects.Copy)
End If
End Sub 'listBox1_MouseDown
Private Sub richTextBox1_DragEnter(ByVal sender As Object, ByVal e As DragEventArgs) Handles richTextBox1.DragEnter
' If the data is text, copy the data to the RichTextBox control.
If e.Data.GetDataPresent("Text") Then
e.Effect = DragDropEffects.Copy
End If
End Sub 'richTextBox1_DragEnter
Private Sub richTextBox1_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles richTextBox1.DragDrop
' Paste the text into the RichTextBox where at selection location.
richTextBox1.SelectedText = e.Data.GetData("System.String", True).ToString()
End Sub 'richTextBox1_DragDrop

0 0