【发布时间】：2014-06-24 07:40:05
【问题描述】：
我正在为 Windows 8.1 通用应用程序创建自定义按钮。我想用它绑定 MVVM 命令。我的所有代码如下。命令绑定适用于默认按钮，但不适用于自定义按钮。此外，视觉状态在自定义按钮中也不起作用。我在 VS 2012/2013 中都尝试了我的代码。我的代码有什么问题？
MyButton.xaml（后面的代码除了构造函数什么都没有）
<ButtonBase
x:Class="App5.MyButton"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App5"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="400">
<ButtonBase.Resources>
<Style TargetType="local:MyButton">
<Setter Property="Background" Value="{ThemeResource ButtonBackgroundThemeBrush}"/>
<Setter Property="Foreground" Value="{ThemeResource ButtonForegroundThemeBrush}"/>
<Setter Property="BorderBrush" Value="{ThemeResource ButtonBorderThemeBrush}"/>
<Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}"/>
<Setter Property="Padding" Value="12,4,12,4"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
<Setter Property="FontWeight" Value="SemiBold"/>
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:MyButton">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Border">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPointerOverBackgroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPointerOverForegroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Border">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPressedBackgroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPressedForegroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Border">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonDisabledBackgroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="Border">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonDisabledBorderThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonDisabledForegroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisualWhite"/>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisualBlack"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Unfocused"/>
<VisualState x:Name="PointerFocused"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Margin="3">
<ContentPresenter x:Name="ContentPresenter" AutomationProperties.AccessibilityView="Raw" ContentTemplate="{TemplateBinding ContentTemplate}" ContentTransitions="{TemplateBinding ContentTransitions}" Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Border>
<Rectangle x:Name="FocusVisualWhite" IsHitTestVisible="False" Opacity="0" StrokeDashOffset="1.5" StrokeEndLineCap="Square" Stroke="{ThemeResource FocusVisualWhiteStrokeThemeBrush}" StrokeDashArray="1,1"/>
<Rectangle x:Name="FocusVisualBlack" IsHitTestVisible="False" Opacity="0" StrokeDashOffset="0.5" StrokeEndLineCap="Square" Stroke="{ThemeResource FocusVisualBlackStrokeThemeBrush}" StrokeDashArray="1,1"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ButtonBase.Resources>
<Grid>
</Grid>
</ButtonBase>
MainPage.xaml
<Page x:Name="page"
......>
<Grid x:Name="root" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<local:MyButton x:Name="btn" Content="Custom" Command="{Binding ViewModel.DoWorkCommand, ElementName=page}" />
<Button HorizontalAlignment="Right" Content="Default" Command="{Binding ViewModel.DoWorkCommand, ElementName=page}" />
</Grid>
MainPage.xaml.cs
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
viewModel = new ViewModel();
//btn.Command = viewModel.DoWorkCommand; That's working but I don't want that.
}
private ViewModel viewModel;
public ViewModel ViewModel
{
get { return this.viewModel; }
}
}
ViewModel.cs
public class ViewModel
{
RelayCommand _doWorkCommand;
public RelayCommand DoWorkCommand
{
get
{
if (_doWorkCommand == null)
{
_doWorkCommand = new RelayCommand(DoWork);
}
return _doWorkCommand;
}
set
{
_doWorkCommand = value;
}
}
public void DoWork()
{
}
}
RelayCommand.cs
public class RelayCommand : ICommand
{
private readonly Action _execute;
private readonly Func<bool> _canExecute;
public event EventHandler CanExecuteChanged;
public RelayCommand(Action execute)
: this(execute, null)
{
}
public RelayCommand(Action execute, Func<bool> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
return _canExecute == null ? true : _canExecute();
}
public void Execute(object parameter)
{
_execute();
}
public void RaiseCanExecuteChanged()
{
var handler = CanExecuteChanged;
if (handler != null)
{
handler(this, EventArgs.Empty);
}
}
}
【问题讨论】：
标签： c# xaml mvvm windows-runtime winrt-xaml