确定何时以及在文本框中添加或删除哪个字符

Determine when and which character is added or deleted in a Text Box(确定何时以及在文本框中添加或删除哪个字符)

问题描述

我在 WPF 应用程序中有一个简单的文本框.

I have a simple text box in a WPF application.

我需要知道何时在文本框中添加/删除了一个字符、哪个字符以及在何处添加或删除了该字符.

I need to know when a character was added/deleted in the text box, which character and where it was added or deleted.

我想过使用TextBox.KeyDown事件，但是有一些问题:

I thought about using the TextBox.KeyDown event, but it has some problems:

• 我不知道角色是在哪里添加或删除的.
• 我不知道如何确定添加了哪个字符(来自 KeyEventArgs).

有什么想法吗?

推荐答案

找到了解决方案.在 WPF 中，TextBox.TextChanged 事件有一个 TextChangedEventArgs.在这个类中，有一个名为 Changes 的属性.

Found the solution. In WPF, the TextBox.TextChanged event has a TextChangedEventArgs. In this class, there is a property named Changes.

这是我的代码:

private void textBox1_TextChanged(object sender, TextChangedEventArgs e)
{
    foreach (var change in e.Changes)
    {
        if (change.AddedLength > 0 && change.RemovedLength == 0)
        {
            if (change.AddedLength == 1)
            {
                AddCharacter(textBox1.Text[change.Offset], change.Offset);
            }
            else
            {
                AddString(textBox1.Text.Substring(change.Offset, change.AddedLength), change.Offset);  
            }
        }
        else if (change.AddedLength == 0 && change.RemovedLength > 0)
        {
            if (change.RemovedLength == 1)
            {
                RemoveCharacter(change.Offset);
            }
            else
            {
                RemoveString(change.Offset, change.RemovedLength + change.Offset);
            }
        }
        else if (change.AddedLength == 1 & change.RemovedLength == 1)
        {
            ReplaceCharacter(change.Offset, textBox1.Text[change.Offset]);
        }
        else
        {
            ReplaceString(change.Offset, change.Offset + change.RemovedLength, textBox1.Text.Substring(change.Offset, change.AddedLength));
        }
    }
}

现在我只需要等待两天就可以接受这个答案.:)

Now I just need to wait two days to accept this answer. :)

还是谢谢.

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