如何：将数据发送到活动的 MDI 子窗体

通常，在多文档界面 (MDI) 应用程序的上下文中，需要将数据发送到活动子窗口，例如用户将数据从剪贴板中粘贴到 MDI 应用程序中。

将数据从剪贴板发送到活动 MDI 子窗口

• 在方法中，将剪贴板上的文本复制到活动子窗体的活动控件。

  提示

  此示例假定有一个 MDI 父窗体 (Form1)，其中包含一个或多个含有 RichTextBox 控件的 MDI 子窗口。 有关更多信息，请参见创建 MDI 父窗体。

  Public Sub mniPaste_Click(ByVal sender As Object, _
     ByVal e As System.EventArgs) Handles mniPaste.Click
  
     ' Determine the active child form.
     Dim activeChild As Form = Me.ParentForm.ActiveMDIChild
  
     ' If there is an active child form, find the active control, which
     ' in this example should be a RichTextBox.
     If (Not activeChild Is Nothing) Then
        Try
           Dim theBox As RichTextBox = Ctype(activeChild.ActiveControl, RichTextBox)
           If (Not theBox Is Nothing) Then
              ' Create a new instance of the DataObject interface.
              Dim data As IDataObject = Clipboard.GetDataObject()
              ' If the data is text, then set the text of the 
              ' RichTextBox to the text in the clipboard.
              If (data.GetDataPresent(DataFormats.Text)) Then
                 theBox.SelectedText = data.GetData(DataFormats.Text).ToString()
              End If
           End If
        Catch
           MessageBox.Show("You need to select a RichTextBox.")
        End Try
     End If
  End Sub
  

  protected void mniPaste_Click (object sender, System.EventArgs e)
  {
    // Determine the active child form.
     Form activeChild = this.ParentForm.ActiveMdiChild;
  
     // If there is an active child form, find the active control, which
     // in this example should be a RichTextBox.
     if (activeChild != null)
     {
        try 
        {
           RichTextBox theBox = (RichTextBox)activeChild.ActiveControl;
           if (theBox != null)
           {
              // Create a new instance of the DataObject interface.
              IDataObject data = Clipboard.GetDataObject();
              // If the data is text, then set the text of the 
              // RichTextBox to the text in the clipboard.
              if (data.GetDataPresent(DataFormats.Text))
              {
                 theBox.SelectedText = data.GetData(DataFormats.Text).ToString();               
              }
           }
        }
        catch 
        {
           MessageBox.Show("You need to select a RichTextBox.");
        }
     }
  }
  

  private void mniPaste_Click(System.Object sender, System.EventArgs e) 
  {
     // Determine the active child form.
     Form activeChild = this.get_ActiveMdiChild();
  
     // If there is an active child form, find the active control, which
     // in this example should be a RichTextBox.
     if ( activeChild  != null  ) 
     {
        try 
        {
           RichTextBox theBox = ((RichTextBox)(activeChild.get_ActiveControl()));
           if ( theBox  != null  ) 
           {
              // Put the selected text on the Clipboard.
              Clipboard.SetDataObject(theBox.get_SelectedText());
           }
        } 
        catch(System.Exception exp)
        {
           MessageBox.Show("You need to select a RichTextBox.");
        }
     }
  }
  

请参见

任务

如何：创建 MDI 父窗体

如何：创建 MDI 子窗体

如何：确定活动的 MDI 子窗体

如何：排列 MDI 子窗体

其他资源

多文档界面 (MDI) 应用程序