Question

VB.NET拖放文本文件到TextBox获得其路径。

Answer 1

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
TextBox1.AllowDrop = True
End Sub

Private Sub TextBoxDragEnter(sender As Object, e As DragEventArgs) Handles TextBox1.DragEnter
If e.Data.GetDataPresent(DataFormats.FileDrop) Then
Dim files As String()
Try
files = CType(e.Data.GetData(DataFormats.FileDrop), String())
Me.TextBox1.Text = files(files.Length - 1)
Catch ex As Exception
MessageBox.Show(ex.Message)
Return
End Try
End If
End Sub

TextBox1.AllowDrop = True 是开启拖放支持，可以在窗体设计器里面开启它，也可以代码开启。

Answer 2

Private MouseIsDown As Boolean = False

Private Sub TextBox1_MouseDown(ByVal sender As Object, ByVal e As _
System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
' Set a flag to show that the mouse is down.
MouseIsDown = True
End Sub

Private Sub TextBox1_MouseMove(ByVal sender As Object, ByVal e As _
System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseMove
If MouseIsDown Then
' Initiate dragging.
TextBox1.DoDragDrop(TextBox1.Text, DragDropEffects.Copy)
End If
MouseIsDown = False
End Sub

Private Sub TextBox2_DragEnter(ByVal sender As Object, ByVal e As _
System.Windows.Forms.DragEventArgs) Handles TextBox2.DragEnter
' Check the format of the data being dropped.
If (e.Data.GetDataPresent(DataFormats.Text)) Then
' Display the copy cursor.
e.Effect = DragDropEffects.Copy
Else
' Display the no-drop cursor.
e.Effect = DragDropEffects.None
End If
End Sub

Private Sub TextBox2_DragDrop(ByVal sender As Object, ByVal e As _
System.Windows.Forms.DragEventArgs) Handles TextBox2.DragDrop
' Paste the text.
TextBox2.Text = e.Data.GetData(DataFormats.Text)
End Sub
微软的Msdn上面有所有的答案。