【WPF系列】Textbox

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Style定义实例

给Textbox定义一个阴影效果。

UpdateSourceTrigger

默认UpdateSourceTrigger为LostFoucs，有时需要及时CommitValue，则需要设置为PropertyChanged。这样当Text属性的值发生变化时，我们的值就能及时更新到Datasource中。

更多参考

How to: Control When the TextBox Text Updates the Source

NumberTextbox

使用NubmberTextboxBehavior
将TextBox的binding属性中Delay设置为1000

//NumericTextBoxBehavior
/// <summary>
/// This forces a TextBoxBase control to be numeric-entry only
/// </summary>
/// <example>
/// <![CDATA[ <TextBox Cinch:NumericTextBoxBehavior.IsEnabled="True" /> ]]>
/// </example>
public static class NumericTextBoxBehavior
{
#region IsEnabled DP
/// <summary>
/// Dependency Property for turning on numeric behavior in a TextBox.
/// </summary>
public static readonly DependencyProperty IsEnabledProperty =
DependencyProperty.RegisterAttached("IsEnabled",
typeof(bool), typeof(NumericTextBoxBehavior),
new UIPropertyMetadata(false, OnEnabledStateChanged)); /// <summary>
/// Attached Property getter for the IsEnabled property.
/// </summary>
/// <param name="source">Dependency Object</param>
/// <returns>Current property value</returns>
public static bool GetIsEnabled(DependencyObject source)
{
return (bool)source.GetValue(IsEnabledProperty);
} /// <summary>
/// Attached Property setter for the IsEnabled property.
/// </summary>
/// <param name="source">Dependency Object</param>
/// <param name="value">Value to set on the object</param>
public static void SetIsEnabled(DependencyObject source, bool value)
{
source.SetValue(IsEnabledProperty, value);
} /// <summary>
/// This is the property changed handler for the IsEnabled property.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private static void OnEnabledStateChanged(DependencyObject sender,
DependencyPropertyChangedEventArgs e)
{
TextBox tb = sender as TextBox;
if (tb == null)
return; tb.PreviewTextInput -= tbb_PreviewTextInput;
DataObject.RemovePastingHandler(tb, OnClipboardPaste); bool b = ((e.NewValue != null && e.NewValue.GetType() == typeof(bool))) ?
(bool)e.NewValue : false;
if (b)
{
tb.PreviewTextInput += tbb_PreviewTextInput;
DataObject.AddPastingHandler(tb, OnClipboardPaste);
}
} #endregion #region Private Methods /// <summary>
/// This method handles paste and drag/drop events
/// onto the TextBox. It restricts the character
/// set to numerics and ensures we have consistent behavior.
/// </summary>
/// <param name="sender">TextBox sender</param>
/// <param name="e">EventArgs</param>
private static void OnClipboardPaste(object sender, DataObjectPastingEventArgs e)
{
TextBox tb = sender as TextBox;
string text = e.SourceDataObject.GetData(e.FormatToApply) as string; if (tb != null && !string.IsNullOrEmpty(text) && !Validate(tb, text))
e.CancelCommand();
} /// <summary>
/// This checks if the resulting string will match the regex expression
/// </summary>
static void tbb_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
TextBox tb = sender as TextBox; if (tb != null && !Validate(tb, e.Text))
e.Handled = true;
} #endregion private static bool Validate(TextBox tb, string newContent)
{
string testString = string.Empty;
// replace selection with new text.
if (!string.IsNullOrEmpty(tb.SelectedText))
{
string pre = tb.Text.Substring(0, tb.SelectionStart);
string after = tb.Text.Substring(tb.SelectionStart + tb.SelectionLength,
tb.Text.Length - (tb.SelectionStart + tb.SelectionLength));
testString = pre + newContent + after;
}
else
{
string pre = tb.Text.Substring(0, tb.CaretIndex);
string after = tb.Text.Substring(tb.CaretIndex,
tb.Text.Length - tb.CaretIndex);
testString = pre + newContent + after;
} Regex regExpr = new Regex(@"^([-+]?)(\d*)([,.]?)(\d*)$");
if (regExpr.IsMatch(testString))
return true; return false;
}
}

WaterMark/HintText/PlaceHoder

通过Style
通过AttachBehavior
通过自定义控件

1.给TextBox添加水印效果（提示文字）

<Style x:Key="placeHolder" TargetType="{x:Type TextBox}" BasedOn="{StaticResource {x:Type TextBox}}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TextBox}">
<Grid>
<TextBox Text="{Binding Path=Text,
RelativeSource={RelativeSource TemplatedParent},
Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged,
Delay=1000}"
x:Name="textSource"
Background="Transparent"
Panel.ZIndex="2" />
<TextBox Text="{TemplateBinding Tag}" Background="{TemplateBinding Background}" Panel.ZIndex="1">
<TextBox.Style>
<Style TargetType="{x:Type TextBox}">
<Setter Property="Foreground" Value="Transparent" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=Text, Source={x:Reference textSource}}" Value="">
<Setter Property="Foreground" Value="LightGray" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>