如何将文本从一个文本框显示到另一个文本框

Question

该代码用于使用VB.NET运行CMD。我想做的是，当我输入＆＃34; ipconfig＆＃34;然后单击ExecuteButton，会出现很多文本，其中一个单词将是＆＃34; DNS＆＃34;。当单词＆＃34; DNS＆＃34;已经出现在OutputTextBox中，我希望StatusTextBox显示文本＆＃34; It Works＆＃34;。

以下是代码：

Public Class Form1

Private WithEvents MyProcess As Process
Private Delegate Sub AppendOutputTextDelegate(ByVal text As String)



Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Me.AcceptButton = ExecuteButton
    MyProcess = New Process
    With MyProcess.StartInfo
        .FileName = "CMD.EXE"
        .UseShellExecute = False
        .CreateNoWindow = True
        .RedirectStandardInput = True
        .RedirectStandardOutput = True
        .RedirectStandardError = True
    End With
    MyProcess.Start()

    MyProcess.BeginErrorReadLine()
    MyProcess.BeginOutputReadLine()
    AppendOutputText("Process Started at: " & MyProcess.StartTime.ToString)

    If OutputTextBox.Text = "DNS" Then
        StatusTextBox.Text = "It Works"
    End If

End Sub

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
    MyProcess.StandardInput.WriteLine("EXIT")
    MyProcess.StandardInput.Flush()
    MyProcess.Close()
End Sub

Private Sub MyProcess_ErrorDataReceived(ByVal sender As Object, ByVal e As System.Diagnostics.DataReceivedEventArgs) Handles MyProcess.ErrorDataReceived
    AppendOutputText(vbCrLf & "Error: " & e.Data)
End Sub

Private Sub MyProcess_OutputDataReceived(ByVal sender As Object, ByVal e As System.Diagnostics.DataReceivedEventArgs) Handles MyProcess.OutputDataReceived
    AppendOutputText(vbCrLf & e.Data)
End Sub

Private Sub ExecuteButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExecuteButton.Click
    MyProcess.StandardInput.WriteLine(InputTextBox.Text)
    MyProcess.StandardInput.Flush()
    InputTextBox.Text = ""
End Sub

Private Sub AppendOutputText(ByVal text As String)
    If OutputTextBox.InvokeRequired Then
        Dim myDelegate As New AppendOutputTextDelegate(AddressOf AppendOutputText)
        Me.Invoke(myDelegate, text)
    Else
        OutputTextBox.AppendText(text)
    End If
End Sub
End Class

以下是一个示例：

指出我的问题，这是我尝试做的事情：

    If OutputTextBox.Text = "DNS" Then
    StatusTextBox.Text = "It Works"
End If

当我输入＆＃34; ipconfig＆＃34;文本＆＃34; DNS＆＃34;将显示但StatusTextBox没有任何反应。我做错了什么？

Answer 1

您的表单加载事件永远不会等待，因此它会立即检查您的条件语句。您可以将条件语句移动到OutputDataReceived Sub吗？

此外，您的OutputTextBox正在追加数据，因此我无法看到它等于＆＃34; DNS＆＃34;。你想看看它吗。包含（＆＃34; DNS＆＃34;）？

如果您将条件移动到OutputDataReceived，并且您要附加到OutputTextBox，您是否只想查看e.Data.Contains（＆＃34; DNS＆＃34;）？

- 编辑 -

Private Delegate Sub ChangeStatusTextDelegate(ByVal text As String)

Private Sub MyProcess_OutputDataReceived(ByVal sender As Object, ByVal e As System.Diagnostics.DataReceivedEventArgs) Handles MyProcess.OutputDataReceived
    AppendOutputText(vbCrLf & e.Data)

    If e.Data.Contains("DNS") Then
        ChangeStatusText("It works")
    End If
End Sub

Private Sub ChangeStatusText(ByVal text As String)
    If txtStatus.InvokeRequired Then
        Dim myDelegate As New ChangeStatusTextDelegate(AddressOf ChangeStatusText)
        Me.Invoke(myDelegate, text)
    Else
        Me.StatusTextBox.Text = text
    End If
End Sub