[VB.NET]OpenFileDialog问题

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OpenFileDialog问题
If OpenFileDialog1.ShowDialog = DialogResult.Cancel Then
Exit Sub
End If
请问为什么两次点击取消才能取消，而savefiledialog确没有问题，
请问如何解决谢谢
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If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.Cancel Then
Exit Sub
End If

应该不是这三行的问题，请多贴些代码。
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Try
Dim myreader = New System.IO.StreamReader(myfilename, System.Text.Encoding.Default)
Dim myreceiver As String = myreader.readline
While Not myreceiver Is Nothing
RichTextBox1.AppendText(myreceiver & vbCrLf)
myreceiver = myreader.readline
End While

Catch ex As Exception
MessageBox.Show(ex.Message, "error ", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Try
感谢楼上确实因为上面的代码，应怎样改呢？
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可能需要filname的定义和赋值部分。
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我是说myfilename。
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Dim result As DialogResult
With Me.OpenFileDialog1
.Title = "Open "
.CheckFileExists = True
.CheckPathExists = True
.Filter = "all(*.txt)|*.txt "
.ShowDialog()
myfilename = .FileName
End With
If result = OpenFileDialog1.ShowDialog.Cancel Then
''If OpenFileDialog1.ShowDialog = DialogResult.Cancel Then
Exit Sub
End If
RichTextBox1.Text = " "
Try
Dim myreader = New System.IO.StreamReader(myfilename, System.Text.Encoding.Default)
Dim myreceiver As String = myreader.readline
While Not myreceiver Is Nothing
RichTextBox1.AppendText(myreceiver & vbCrLf)
myreceiver = myreader.readline
End While

Catch ex As Exception
MessageBox.Show(ex.Message, "error ", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Try
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我上面用了两种判断效果都一样，自己试了是由于
Dim myreader = New System.IO.StreamReader(myfilename, System.Text.Encoding.Default)
此部分要求文件名不能为空，所引起的，不知道怎么解决
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您用了两次ShowDialog，所以会出现两次，（在判断时用ShowDialog和在别处用是一样的）

我帮您把代码改了一下，容易看些：

Public Class Form1

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim myfilename As String = " "

With Me.OpenFileDialog1
.Title = "Open "
.CheckFileExists = True
.CheckPathExists = True
.Filter = "all(*.txt)|*.txt "
.FileName = " "
End With

If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then

RichTextBox1.Text = " "
myfilename = Me.OpenFileDialog1.FileName

Try

Dim myreader = New System.IO.StreamReader(myfilename, System.Text.Encoding.Default)
Dim myreceiver As String = myreader.readline
While Not myreceiver Is Nothing
RichTextBox1.AppendText(myreceiver & vbCrLf)
myreceiver = myreader.readline
End While

Catch ex As Exception
MessageBox.Show(ex.Message, "error ", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Try
End If

End Sub

End Class
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谢谢我也发现这个问题了，非常感谢
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赶时间忙得头脑发热了哈哈
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