已在文本框中选择检测某些文本

Question

我在c#中实现了一个记事本应用程序,所有的功能都很完美,只有一件我无法正确实现.编辑下拉菜单中有一些菜单项,但是它们的启用属性必须根据情况而改变文本框,我有两个情况的问题,我正在寻找一个事件,以便在此事件的eventhandler中更改其启用的属性,这是问题所在:

2)当在文本框中选择了一些文本时,应该启用删除,复制和粘贴选项.我应该检测它吗？我已经测试了texchanged事件,我写了一个类似下面代码的条件但是它不起作用,只是剪贴板运作良好:

private void textBox1_TextChanged(object sender, EventArgs e)
    {
        if (textBox1.SelectionLength> 0)
            button1.Enabled = false;
        if (Clipboard.ContainsText())
            button2.Enabled = false;


    }

我应该如何解决我的问题,因为我必须使用文本框而不是richtextbox.任何建议将不胜感激.非常感谢

Answer 1

找出选择

if (textbox1.SelectionLength > 0)
{

}

对于剪贴板内容,请使用

System.Windows.Forms.Clipboard.getText();

检查剪贴板内容,

IDataObject iData = Clipboard.GetDataObject();
// Is Data Text?
if (iData.GetDataPresent(DataFormats.Text))
    label1.Text = (String)iData.GetData(DataFormats.Text);
else
label1.Text = "Data not found."; 

这是在代码中实现的.您可以像上面一样直接使用它

最重要的是,别忘了

public virtual string SelectedText { get; set; }

这是包含菜单项的完整代码

private void Menu_Copy(System.Object sender, System.EventArgs e)
{
// Ensure that text is selected in the text box.    
if(textBox1.SelectionLength > 0)
    // Copy the selected text to the Clipboard.
    textBox1.Copy();
}

private void Menu_Cut(System.Object sender, System.EventArgs e)
{   
 // Ensure that text is currently selected in the text box.    
 if(textBox1.SelectedText.Length > 0)
    // Cut the selected text in the control and paste it into the Clipboard.
    textBox1.Cut();
 }

Private void Menu_Paste(System.Object sender, System.EventArgs e)
{
// Determine if there is any text in the Clipboard to paste into the text box. 
if(Clipboard.GetDataObject().GetDataPresent(DataFormats.Text))
{
    // Determine if any text is selected in the text box. 
    if(textBox1.SelectionLength > 0)
    {
      // Ask user if they want to paste over currently selected text. 
      if(MessageBox.Show("Do you want to paste over current selection?", "Cut Example", MessageBoxButtons.YesNo) == DialogResult.No)
         // Move selection to the point after the current selection and paste.
         textBox1.SelectionStart = textBox1.SelectionStart + textBox1.SelectionLength;
    }
    // Paste current text in Clipboard into text box.
    textBox1.Paste();
  }
}


private void Menu_Undo(System.Object sender, System.EventArgs e)
{
// Determine if last operation can be undone in text box.    
if(textBox1.CanUndo == true)
{
   // Undo the last operation.
   textBox1.Undo();
   // Clear the undo buffer to prevent last action from being redone.
   textBox1.ClearUndo();
}
}