如果在 vb.net 中找不到代码，则希望事件在带有 MessageBox 的文本框中而不是 gridview 过滤器状态中

Question

如果找不到代码，我想显示 MessageBox 而不是 gridview 过滤器状态。

Dim source1 As New BindingSource()
Private Sub TextBox2_KeyDown(ByVal sender As Object, ByVal e As KeyEventArgs) Handles TextBox2.KeyDown
        If TextBox2.Text = "" Then
            source1.Filter = ""
            Me.DataGridView1.Refresh()
        Else
            If e.KeyCode = Keys.Enter Then
                source1.Filter = "CODE like  '' + '" & TextBox2.Text & "' + '' "
                Me.DataGridView1.Refresh()
            End If
        End If
    End Sub

Answer 1

在其他内部添加另一个if语句，然后检查source1是否有行，如果行＆lt; = 0，则清除过滤器和文本框。

更新了

Dim source1 As New BindingSource()
Private Sub TextBox2_KeyDown(ByVal sender As Object, ByVal e As KeyEventArgs) Handles TextBox2.KeyDown
      If TextBox2.Text = "" Then
          source1.Filter = ""
          Me.DataGridView1.Refresh()
      Else
          If e.KeyCode = Keys.Enter Then
              source1.Filter = "CODE like  '' + '" & TextBox2.Text & "' + '' "
           
               ' If Else Statement to determine the count of your bindingsource
               ' Check the results, if result is less than or equal to 0 
               ' then prompt messagebox and clear the source filter
               If source1.count <= 0
                   source1.Filter = ""
                   TextBox2.Clear()
                   MsgBox("No Result Found!", MsgBoxStyle.Exclamation)
               End If
               Me.DataGridView1.Refresh()
          End If
      End If
End Sub