使用绑定 属性 更新 UserControl UI
Update UserControl UI with a binding property
我有一个可以绑定到 属性 的 UserControl。此 属性 需要更新 UserControl UI。 UserControl 有两个文本块，属性 需要用字符串的一半更新一个文本块，用另一半更新另一个文本块。
用户控件XAML:
<UserControl x:Class="HexView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:LearningWPF"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TextBlock x:Name="txtOne" Width="100" Height="100" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,0,0">Hola</TextBlock>
<TextBlock x:Name="txtTwo" Width="100" Height="100" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="120,10,0,0">Adios</TextBlock>
</Grid>
</UserControl>
UserControl 代码隐藏（VB）
Imports System.ComponentModel
Public Class HexView
Private s_Rawstring As String
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
Public Shared ReadOnly RawStringProperty As DependencyProperty = DependencyProperty.Register("RawString", GetType(String), GetType(HexView))
Public Property Rawstring As String
Get
Return GetValue(RawStringProperty)
End Get
Set(value As String)
SetValue(RawStringProperty, value)
Parse()
End Set
End Property
Private Sub Parse()
txtOne.Text = Rawstring.Substring(0, Rawstring.Length / 2)
txtTwo.Text = Rawstring.Substring(Rawstring.Length / 2)
End Sub
End Class
如果我将 属性 设置为
hexview.rawstring = "This is a sample property"
UserControlUI 已更新，因为它使用 setter 访问器并执行方法 Parse()。但是使用数据绑定不会。
b如有任何反馈，我们将不胜感激。
谢谢
当您使用绑定访问依赖项 属性 时，"Get" 和 "Set" 后面的代码实际上不会被调用。 get'r 和 set'r 只是 "GetValue()" 和 "SetValue()" 的包装器，以方便代码隐藏使用。
我对您问题的简短回答是更改以下代码以至少使其以当前形式运行：
在您的依赖项 属性 上利用 属性ChangedCallback 委托并让它调用 "Parse()" 方法。
Public Shared ReadOnly RawStringProperty As DependencyProperty = DependencyProperty.Register("RawString", GetType(String), GetType(HexView), New PropertyMetadata(New PropertyChangedCallback(AddressOf RawStringPropertyChanged)))
Public Property Rawstring As String
Get
Return GetValue(RawStringProperty)
End Get
Set(value As String)
SetValue(RawStringProperty, value)
End Set
End Property
Private Shared Sub RawStringPropertyChanged(ByVal d As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
Dim control As HexView = CType(d, HexView)
control.Parse()
End Sub
我对你问题的正确回答有点啰嗦：
虽然这是合法的，但您通常应该避免在代码隐藏中按名称引用控件。对于这两个字符串，您应该分别具有依赖属性，然后将文本框绑定到它们。
希望对您有所帮助！
Ryan Flohr的回答可以如你所愿，但既然他提到了啰嗦的方法，我想我也会提出啰嗦的方法。啰嗦的方法绝对是推荐的方法。
后面的代码：
Imports System.ComponentModel
Public Class HexView
Private s_Rawstring As String
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
Public Shared ReadOnly RawStringProperty As DependencyProperty = DependencyProperty.Register("RawString", GetType(String), GetType(HexView), New PropertyMetadata(New PropertyChangedCallback(AddressOf RawStringPropertyChanged)))
Public Property Rawstring As String
Get
Return GetValue(RawStringProperty)
End Get
Set(value As String)
SetValue(RawStringProperty, value)
End Set
End Property
Private Shared Sub RawStringPropertyChanged(ByVal d As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
Dim control As HexView = CType(d, HexView)
control.Parse()
End Sub
Public Shared ReadOnly ParsedStringOneProperty As DependencyProperty = DependencyProperty.Register("ParsedStringOne", GetType(String), GetType(HexView), New PropertyMetadata(String.Empty))
Public Property ParsedStringOne As String
Get
Return GetValue(ParsedStringOneProperty)
End Get
Set(value As String)
SetValue(ParsedStringOneProperty, value)
End Set
End Property
Public Shared ReadOnly ParsedStringTwoProperty As DependencyProperty = DependencyProperty.Register("ParsedStringTwo", GetType(String), GetType(HexView), New PropertyMetadata(String.Empty))
Public Property ParsedStringTwo As String
Get
Return GetValue(ParsedStringTwoProperty)
End Get
Set(value As String)
SetValue(ParsedStringTwoProperty, value)
End Set
End Property
Private Sub Parse()
ParsedStringOne = Rawstring.Substring(0, Rawstring.Length / 2)
ParsedStringTwo = Rawstring.Substring(Rawstring.Length / 2)
End Sub
End Class
XAML:
<UserControl x:Class="HexView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:LearningWPF"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TextBlock x:Name="txtOne" Width="100" Height="100"
HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,0,0"
Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:HexView}},Path=ParsedStringOne}"/>
<TextBlock x:Name="txtTwo" Width="100" Height="100"
HorizontalAlignment="Left" VerticalAlignment="Top" Margin="120,10,0,0"
Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:HexView}},Path=ParsedStringTwo}" />
</Grid>
</UserControl>
编写一个 IValueConverter ，它将为您完成工作。
class ParseStringConv : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (parameter.ToString() == "Left")
return value.ToString().Substring(0, value.ToString().Length / 2);
return value.ToString().Substring(value.ToString().Length / 2);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
用法：
<TextBlock Text="{Binding Name, Converter={StaticResource ParseConv}, ConverterParameter='Left'}" />
<TextBlock Text="{Binding Name, Converter={StaticResource ParseConv}, ConverterParameter='Right'}" />
传递适当的 ConverterParameter。
我有一个可以绑定到 属性 的 UserControl。此 属性 需要更新 UserControl UI。 UserControl 有两个文本块，属性 需要用字符串的一半更新一个文本块，用另一半更新另一个文本块。
用户控件XAML:
<UserControl x:Class="HexView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:LearningWPF"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TextBlock x:Name="txtOne" Width="100" Height="100" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,0,0">Hola</TextBlock>
<TextBlock x:Name="txtTwo" Width="100" Height="100" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="120,10,0,0">Adios</TextBlock>
</Grid>
</UserControl>
UserControl 代码隐藏（VB）
Imports System.ComponentModel
Public Class HexView
Private s_Rawstring As String
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
Public Shared ReadOnly RawStringProperty As DependencyProperty = DependencyProperty.Register("RawString", GetType(String), GetType(HexView))
Public Property Rawstring As String
Get
Return GetValue(RawStringProperty)
End Get
Set(value As String)
SetValue(RawStringProperty, value)
Parse()
End Set
End Property
Private Sub Parse()
txtOne.Text = Rawstring.Substring(0, Rawstring.Length / 2)
txtTwo.Text = Rawstring.Substring(Rawstring.Length / 2)
End Sub
End Class
如果我将 属性 设置为
hexview.rawstring = "This is a sample property"
UserControlUI 已更新，因为它使用 setter 访问器并执行方法 Parse()。但是使用数据绑定不会。
b如有任何反馈，我们将不胜感激。
谢谢
当您使用绑定访问依赖项 属性 时，"Get" 和 "Set" 后面的代码实际上不会被调用。 get'r 和 set'r 只是 "GetValue()" 和 "SetValue()" 的包装器，以方便代码隐藏使用。
我对您问题的简短回答是更改以下代码以至少使其以当前形式运行：
在您的依赖项 属性 上利用 属性ChangedCallback 委托并让它调用 "Parse()" 方法。
Public Shared ReadOnly RawStringProperty As DependencyProperty = DependencyProperty.Register("RawString", GetType(String), GetType(HexView), New PropertyMetadata(New PropertyChangedCallback(AddressOf RawStringPropertyChanged)))
Public Property Rawstring As String
Get
Return GetValue(RawStringProperty)
End Get
Set(value As String)
SetValue(RawStringProperty, value)
End Set
End Property
Private Shared Sub RawStringPropertyChanged(ByVal d As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
Dim control As HexView = CType(d, HexView)
control.Parse()
End Sub
我对你问题的正确回答有点啰嗦：
虽然这是合法的，但您通常应该避免在代码隐藏中按名称引用控件。对于这两个字符串，您应该分别具有依赖属性，然后将文本框绑定到它们。
希望对您有所帮助！
Ryan Flohr的回答可以如你所愿，但既然他提到了啰嗦的方法，我想我也会提出啰嗦的方法。啰嗦的方法绝对是推荐的方法。
后面的代码：
Imports System.ComponentModel
Public Class HexView
Private s_Rawstring As String
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
Public Shared ReadOnly RawStringProperty As DependencyProperty = DependencyProperty.Register("RawString", GetType(String), GetType(HexView), New PropertyMetadata(New PropertyChangedCallback(AddressOf RawStringPropertyChanged)))
Public Property Rawstring As String
Get
Return GetValue(RawStringProperty)
End Get
Set(value As String)
SetValue(RawStringProperty, value)
End Set
End Property
Private Shared Sub RawStringPropertyChanged(ByVal d As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
Dim control As HexView = CType(d, HexView)
control.Parse()
End Sub
Public Shared ReadOnly ParsedStringOneProperty As DependencyProperty = DependencyProperty.Register("ParsedStringOne", GetType(String), GetType(HexView), New PropertyMetadata(String.Empty))
Public Property ParsedStringOne As String
Get
Return GetValue(ParsedStringOneProperty)
End Get
Set(value As String)
SetValue(ParsedStringOneProperty, value)
End Set
End Property
Public Shared ReadOnly ParsedStringTwoProperty As DependencyProperty = DependencyProperty.Register("ParsedStringTwo", GetType(String), GetType(HexView), New PropertyMetadata(String.Empty))
Public Property ParsedStringTwo As String
Get
Return GetValue(ParsedStringTwoProperty)
End Get
Set(value As String)
SetValue(ParsedStringTwoProperty, value)
End Set
End Property
Private Sub Parse()
ParsedStringOne = Rawstring.Substring(0, Rawstring.Length / 2)
ParsedStringTwo = Rawstring.Substring(Rawstring.Length / 2)
End Sub
End Class
XAML:
<UserControl x:Class="HexView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:LearningWPF"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TextBlock x:Name="txtOne" Width="100" Height="100"
HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,10,0,0"
Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:HexView}},Path=ParsedStringOne}"/>
<TextBlock x:Name="txtTwo" Width="100" Height="100"
HorizontalAlignment="Left" VerticalAlignment="Top" Margin="120,10,0,0"
Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:HexView}},Path=ParsedStringTwo}" />
</Grid>
</UserControl>
编写一个 IValueConverter ，它将为您完成工作。
class ParseStringConv : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (parameter.ToString() == "Left")
return value.ToString().Substring(0, value.ToString().Length / 2);
return value.ToString().Substring(value.ToString().Length / 2);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
用法：
<TextBlock Text="{Binding Name, Converter={StaticResource ParseConv}, ConverterParameter='Left'}" />
<TextBlock Text="{Binding Name, Converter={StaticResource ParseConv}, ConverterParameter='Right'}" />
传递适当的 ConverterParameter。