Question

我是devexpress WPF应用中的新用户。我真的想学习如何检测文本框事件的任何变化？例如;有2个文本框（devexpress）（txt1，txt2）。如果我擦除txt1上的值，txt2必须擦除自己的值。

像那样：

  private void txt1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Delete)
        {
            txt2.Text = String.Empty;
        }
    }

是真的吗？你能救我吗？

Answer 1

如果txt2的文本必须与txt1完全相同，请使用绑定：

<TextBox Name="txt2" Text="{Binding ElementName=txt1, Path=Text}"/>

如果您只想获得更改，请尝试此操作（使用TextChanged-Event代替KeyDown，因为您还可以将字符串粘贴到文本框中）：

string oldtext = "";
private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
    string removedstring = "";
    string addedstring = "";
    TextBox source = (TextBox)e.Source;
    TextChange t = e.Changes.First();

    if (t.RemovedLength > 0)
    {
        removedstring = oldtext.Substring(t.Offset, t.RemovedLength);
    }

    if (t.AddedLength > 0)
    {
        addedstring = source.Text.Substring(t.Offset, t.AddedLength);
    }

    oldtext = source.Text;
}

如果要按代码

设置txt2.Text = txt1.Text

private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
    {
        TextBox source = (TextBox)e.Source;
        TextChange t = e.Changes.First();

        string first = txt2.Text.Substring(0, t.Offset);
        string added = source.Text.Substring(t.Offset, t.AddedLength);
        string last = (t.Offset+1>tbrt.Text.Length)?"":txt2.Text.Substring(t.Offset, txt2.Text.Length-1);
        last = last.Remove(0, t.RemovedLength);
        txt2.Text = first + added + last;
    }

如何处理Devexpress WPF TextBox Changed Event？

1 个答案: