WPF DataTrigger的两个用法
1.用在textbox等输入控件上，验证输入是否合法。
首先定义一个Converter，
1
class
DataConverter : IValueConverter
2
{
3
object
IValueConverter.Convert(
object
value, Type targetType,
object
parameter, System.Globalization.CultureInfo culture)
4
{
5
if
(value
==
null
)
return
false
;
6
if
(
string
.IsNullOrEmpty(value.ToString()))
return
false
;
7
if
(
!
Regex.IsMatch(value.ToString(),
"
^[1-9]\\d*$
"
))
return
false
;
8
return
Convert.ToInt32(value)
<
100
;
9
}
10
11
object
IValueConverter.ConvertBack(
object
value, Type targetType,
object
parameter, System.Globalization.CultureInfo culture)
12
{
13
return
null
;
14
}
15
}
2.Xaml里面这样子写，意思是输入的数字，如果小于100则显示为红色。
代码
1
<
TextBox Canvas.Left
=
"
146
"
Canvas.Top
=
"
199
"
Height
=
"
23
"
Name
=
"
textBox2
"
Width
=
"
120
"
Margin
=
"
62,47,321,241
"
>
2
<
TextBox.Resources
>
3
<
Style TargetType
=
"
{x:Type TextBox}
"
>
4
<
Style.Triggers
>
5
<
DataTrigger Binding
=
"
{Binding RelativeSource={RelativeSource Self},Path=Text,Converter={StaticResource dc}}
"
Value
=
"
True
"
>
6
<
Setter Property
=
"
Foreground
"
Value
=
"
Red
"
></
Setter
>
7
</
DataTrigger
>
8
</
Style.Triggers
>
9
</
Style
>
10
</
TextBox.Resources
>
11
</
TextBox
>
3.combox等列表控件里面，也可以用做数据筛选。下面例子中筛选出小于100的项目，红色显示
数据源定义为：
代码
1
List
<
object
>
objList
=
new
List
<
object
>
();
2
for
(
int
i
=
0
; i
<
200
; i
+=
10
)
3
{
4
objList.Add(
new
{ Display
=
"
d
"
+
i.ToString(), Tag
=
i.ToString() });
5
}
6
7
comboBox1.ItemsSource
=
objList;
Xaml：
代码
1
<
ComboBox Canvas.Left
=
"
694
"
Canvas.Top
=
"
24
"
Height
=
"
23
"
Name
=
"
comboBox1
"
Width
=
"
120
"
Margin
=
"
205,47,178,241
"
>
2
<
ComboBox.ItemTemplate
>
3
<
DataTemplate
>
4
<
StackPanel Orientation
=
"
Horizontal
"
>
5
<
TextBlock Text
=
"
{Binding Display}
"
Name
=
"
t1
"
></
TextBlock
>
6
<
TextBlock Text
=
"
--
"
Name
=
"
t2
"
/>
7
<
TextBlock Text
=
"
{Binding Tag}
"
Name
=
"
t3
"
></
TextBlock
>
8
</
StackPanel
>
9
<
DataTemplate.Triggers
>
10
<
DataTrigger Binding
=
"
{Binding Path=Tag,Converter={StaticResource dc}}
"
Value
=
"
True
"
>
11
<
Setter Property
=
"
Foreground
"
TargetName
=
"
t1
"
Value
=
"
Red
"
/>
12
<
Setter Property
=
"
Foreground
"
TargetName
=
"
t2
"
Value
=
"
Red
"
/>
13
<
Setter Property
=
"
Foreground
"
TargetName
=
"
t3
"
Value
=
"
Red
"
/>
14
</
DataTrigger
>
15
</
DataTemplate.Triggers
>
16
</
DataTemplate
>
17
</
ComboBox.ItemTemplate
>
18
</
ComboBox
>
源码下载 http://files.cnblogs.com/xiaokang088/WpfDataTrigger.rar