WPF 特性之一 附加属性 在本文里实现文本框内容的验证
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public
class
TextBoxHelper:
DependencyObject
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{
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public static bool GetisOnlyNumber(DependencyObject obj)
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{
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return (
bool)obj.GetValue(isOnlyNumberProperty);
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}
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public static void SetisOnlyNumber(DependencyObject obj, bool value)
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{
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obj.SetValue(isOnlyNumberProperty,
value);
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}
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// Using a DependencyProperty as the backing store for isOnlyNumber. This enables animation, styling, binding, etc...
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public
static
readonly DependencyProperty isOnlyNumberProperty =
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DependencyProperty.RegisterAttached(
"isOnlyNumber",
typeof(
bool),
typeof(TextBoxHelper),
new PropertyMetadata(
false,OnIsOnlyNumberChange));
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private static void OnIsOnlyNumberChange(DependencyObject d, DependencyPropertyChangedEventArgs e)
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{
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var text = d
as TextBox;
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if ((
bool)e.NewValue)
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{
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text.PreviewTextInput += text_PreviewTextInput;
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}
else{
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text.PreviewTextInput -= text_PreviewTextInput;
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}
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}
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static void text_PreviewTextInput(object sender, System.Windows.Input.TextCompositionEventArgs e)
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{
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e.Handled = IsNotNumber(e.Text);
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}
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private static bool IsNotNumber(string content)
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{
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Regex regex =
new Regex(
"[^0-9]");
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return regex.IsMatch(content);
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}
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}
引用命名空间
xmlns:bhx ="clr-namespace:WPF.Behaviors"
<TextBox bhx:TextBoxHelper.isOnlyNumber="True" HorizontalAlignment="Left" Height="23" Margin="10,131,0,0" TextWrapping="Wrap" Text="{Binding CurrentBook.Pages}" VerticalAlignment="Top" Width="120"/>