在文本框中更改粘贴内容

Question

如何动态更改将在TextBox中粘贴的内容.

以下是我订阅活动的方式:

DataObject.AddPastingHandler (uiTextBox, TextBoxPaste);

以下是我定义事件处理程序的方法:

private void TextBoxPaste (object sender, DataObjectPastingEventArgs args)
{
    string clipboard = args.DataObject.GetData (typeof (string)) as string;

    Regex nonNumeric = new System.Text.RegularExpressions.Regex (@"\D");
    string result = nonNumeric.Replace (clipboard, String.Empty);

    // I can't just do "args.DataObject.SetData (result)" here.
}

Answer 1

因为DataObject被冻结,所以不能调用args.DataObject.SetData("some data").你可以做的是完全替换DataObject:

private void TextBoxPaste(object sender, DataObjectPastingEventArgs e) {
        string text = (String)e.DataObject.GetData(typeof(String));
        DataObject d = new DataObject();
        d.SetData(DataFormats.Text, text.Replace(Environment.NewLine, " "));
        e.DataObject = d;
 }

Answer 2

我可以想到两种方式,其中没有一种非常有吸引力:)两种方式都包括取消粘贴命令.

第一种方法是取消粘贴命令,然后计算粘贴后粘贴后文本的样子result.

private void TextBoxPaste(object sender, DataObjectPastingEventArgs args)
{
    string clipboard = args.DataObject.GetData(typeof(string)) as string;

    Regex nonNumeric = new System.Text.RegularExpressions.Regex(@"\D");
    string result = nonNumeric.Replace(clipboard, String.Empty);

    int start = uiTextBox.SelectionStart;
    int length = uiTextBox.SelectionLength;
    int caret = uiTextBox.CaretIndex;

    string text = uiTextBox.Text.Substring(0, start);
    text += uiTextBox.Text.Substring(start + length);

    string newText = text.Substring(0, uiTextBox.CaretIndex) + result;
    newText += text.Substring(caret);
    uiTextBox.Text = newText;
    uiTextBox.CaretIndex = caret + result.Length;

    args.CancelCommand();
}

另一种方法是取消粘贴命令,更改剪贴板中的文本,然后重新执行粘贴.这还需要您在实际粘贴命令和手动调用粘贴命令之间有所不同.像这样的东西

bool m_modifiedPaste = false;
private void TextBoxPaste(object sender, DataObjectPastingEventArgs args)
{
    if (m_modifiedPaste == false)
    {
        m_modifiedPaste = true;
        string clipboard = args.DataObject.GetData(typeof(string)) as string;

        Regex nonNumeric = new System.Text.RegularExpressions.Regex(@"\D");
        string result = nonNumeric.Replace(clipboard, String.Empty);

        args.CancelCommand();

        Clipboard.SetData(DataFormats.Text, result);
        ApplicationCommands.Paste.Execute(result, uiTextBox);
    }
    else
    {
        m_modifiedPaste = false;
    }
}