WPF TextBox限制输入控制

WPF TextBox限制输入控制

设置TextBox只能输入整数和小数；

<TextBox x:Name="textBox" Width="100" Height="22" input:InputMethod.IsInputMethodEnabled="False" PreviewTextInput="textBox_PreviewTextInput" LostFocus="textBox_LostFocus"/>

private void textBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
    var textElem = (sender as TextBox);

    if(textElem.Text.StartsWith("0") && textElem.Text.Length == 1)
    {
        if (e.Text == "0")
        {
            e.Handled = true;
            return;
        }
        else if (e.Text == ".")
        {
            e.Handled = false;
        }
        else
            textElem.Text = "";
    }

    if(textElem.Text.Length == 1 && e.Text == ".")
    {
        e.Handled = true;
        textElem.Text = "0.";
        textElem.SelectionStart = textElem.Text.Length;
        return;
    }

    //解决连续输入很多.
    if ((string.IsNullOrWhiteSpace(textElem.Text)|| textElem.Text.Contains(".")) && e.Text == ".")
    {
        e.Handled = true;
        return;
    }

    //禁止在0前面继续输入0
    //int index = ((System.Windows.Controls.TextBox)e.Source).CaretIndex;
    //if (textElem.Text.StartsWith("0.") && index == 0 && e.Text == "0")
    //{
    //    e.Handled = true;
    //    return;
    //}

    //不能输入非数字
    if (Regex.IsMatch(e.Text, @"[^\d+\.{0,1}\d+]+"))
    {
        e.Handled = true;
        return;
    }            
}

private void textBox_LostFocus(object sender, RoutedEventArgs e)
{
    var textElem = (sender as TextBox);
    if (string.IsNullOrEmpty(textElem.Text))
        textElem.Text = "0";
    else if (textElem.Text.EndsWith("."))
        textElem.Text = textElem.Text.Remove(textElem.Text.Length - 1, 1);
}