已在文本框中选择“检测某些文本”
本文关键字:文本 检测 选择 | 更新日期: 2023-09-27 17:58:33
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,只有一件事我无法准确实现。编辑下拉菜单中有一些菜单项,但它们的启用属性必须根据文本框的情况而更改,我有两种情况的问题,我正在寻找一个事件,以便在该事件的事件处理程序中更改其启用的属性,问题是:
2) 当在文本框中选择某些文本时,应该启用删除、复制和粘贴选项。我应该如何检测它?我测试了texchange事件,我写了一个类似下面代码的条件,但它不起作用,只是剪贴板工作得很好:
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,顺便说一句,我必须使用文本框而不是richtextbox。如有任何建议,我们将不胜感激。非常感谢
查找选择
if (textbox1.SelectionLength > 0)
{
}
对于剪贴板内容,使用
System.Windows.Forms.Clipboard.getText();
检查剪贴板内容的依据,
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。你可以直接使用上面的
最重要的是,不要忘记
public virtual string SelectedText { get; set; }
这是菜单项的完整代码
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();
}
}
为我工作。
private void button2_Click(object sender, EventArgs e)
{
if (textBox1.SelectedText != String.Empty)
{
label1.Text = textBox1.SelectedText;
}
if (Clipboard.ContainsText())
{
label2.Text = Clipboard.GetText();
}
}
在我看来,最简单的方法是定义启用/禁用方法:
private void editMenuItemOpened(object sender, EventArgs e)
{
//enable copy and cut only if some text is selected
copyMenuItem.Enabled = cutMenuItem.Enabled = textBox1.SelectionLength > 0;
//enable paste only if there's some text in the clipboard to paste
pasteMenuItem.Enabled = Clipboard.ContainsText();
}
并将其附加到editMenuItem.DropDownOpened
事件(使用Forms时)或editMenuItem.SubmenuOpened
事件(使用WPF时;在这种情况下,您可能还希望使用RoutedEventArgs
而不是EventArgs
)。
或者,如果您正在使用WPF,则可以使用textBox1.SelectionChanged
事件。它不存在于Forms中,因此在这种情况下,您可能应该使用textBox1.MouseUp
和textBox1.KeyUp
事件的组合。
对于问题的后半部分:
textbox1.TextChanged += new TextChangedEventHandler(textbox1_TextChanged);
private void textbox1_TextChanged(object sender, EventArgs e)
{
if (textbox1.Text.Length > 0)
{
// enable delete, copy & paste functions
}
else
{
// disable delete, copy & paste functions
}
}
private void textBox1_SelectionChanged(object sender, EventArgs e)
{
if (textBox1.SelectedText.Length > 0)
{
txtTextSelected.Text = textBox1.SelectedText;
Clipboard.SetText(textBox2.Text);//This is optional
}
else
{
textBox2.Text = "";
Clipboard.Clear();//This is optional
}
}