WPF TextBox 验证输入

//验证输入为数字
private void txt_time_KeyDown(object sender, KeyEventArgs e)
{
if (!((e.Key >= Key.D0 && e.Key <= Key.D9) || (e.Key >= Key.NumPad0 && e.Key <= Key.NumPad9)))
{
e.Handled = true;
}
}

//屏蔽粘贴非法字符
private void txt_time_TextChanged(object sender, TextChangedEventArgs e)
{
var textBox = sender as TextBox;
TextChange[] change = new TextChange[e.Changes.Count];
e.Changes.CopyTo(change, 0);

int offset = change[0].Offset;
if (change[0].AddedLength > 0)
{
double num = 0;
if (!Double.TryParse(textBox.Text, out num))
{
textBox.Text = textBox.Text.Remove(offset, change[0].AddedLength);
textBox.Select(offset, 0);
}
}
}

//屏蔽非法按键
private void txtAge_KeyDown(object sender, KeyEventArgs e)
{
TextBox txt = sender as TextBox;
if ((e.Key >= Key.NumPad0 && e.Key <= Key.NumPad9) || e.Key == Key.Decimal)
{
if (txt.Text.Contains(".") && e.Key == Key.Decimal)
{
e.Handled = true;
return;
}
e.Handled = false;
}
else if (((e.Key >= Key.D0 && e.Key <= Key.D9) || e.Key == Key.OemPeriod) && e.KeyboardDevice.Modifiers != ModifierKeys.Shift)
{
if (txt.Text.Contains(".") && e.Key == Key.OemPeriod)
{
e.Handled = true;
return;
}
e.Handled = false;
}
else
{
e.Handled = true;
}
}

//屏蔽中文输入和非法字符粘贴输入
private void txtAge_TextChanged(object sender, TextChangedEventArgs e)
{
TextBox textBox = sender as TextBox;
TextChange[] change = new TextChange[e.Changes.Count];
e.Changes.CopyTo(change, 0);
int offset = change[0].Offset;
if (change[0].AddedLength > 0)
{
double num = 0;
if (!Double.TryParse(textBox.Text, out num))
{
textBox.Text = textBox.Text.Remove(offset, change[0].AddedLength);
textBox.Select(offset, 0);
}
}
}