C# ListView.ItemTemplate中的UWP-状态触发器
在我的ListViewC# ListView.ItemTemplate中的UWP-状态触发器,c#,xaml,uwp,uwp-xaml,visualstatemanager,C#,Xaml,Uwp,Uwp Xaml,Visualstatemanager,在我的ListViewItemTemplate中将ColorAnimation添加到VisualStateManager时遇到问题。VisualStateManager似乎没有更改其视觉状态 我在这里试图做的是启动一个情节提要,它将开始平滑地更改矩形。只要其基础viewmodel的IsReady属性值更改,就在列表ViewItem上填充颜色 我做错了什么?如何正确地做到这一点(最好没有无意义的用户控制) 这是XAML: <Page x:Class="App1.MainPage"
ItemTemplate
中将ColorAnimation
添加到VisualStateManager
时遇到问题。VisualStateManager似乎没有更改其视觉状态
我在这里试图做的是启动一个情节提要
,它将开始平滑地更改矩形。只要其基础viewmodel的IsReady属性值更改,就在列表ViewItem
上填充颜色
我做错了什么?如何正确地做到这一点(最好没有无意义的用户控制)
这是XAML:
<Page
x:Class="App1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App1"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<ListView ItemsSource="{x:Bind MyList}">
<ListView.ItemTemplate>
<DataTemplate x:DataType="local:B">
<UserControl>
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="group">
<VisualState x:Name="state1">
<VisualState.StateTriggers>
<StateTrigger IsActive="{x:Bind IsReady, Mode=OneWay}"/>
</VisualState.StateTriggers>
<Storyboard>
<ColorAnimation Duration="0:0:1.8" To="Red" Storyboard.TargetProperty="(Rectangle.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="rect" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Rectangle x:Name="rect" Fill="Blue" Width="20" Height="20" />
</Grid>
</UserControl>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Button Click="Button_Click">Test</Button>
</Grid>
</Page>
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
namespace App1
{
public abstract class NotifyPropertyChangedBase : INotifyPropertyChanged
{
protected NotifyPropertyChangedBase()
{
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void RaisePropertyChanged([CallerMemberName]string propertyName = null)
{
this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
public class B : NotifyPropertyChangedBase
{
private bool isReady;
public bool IsReady
{
get { return isReady; }
set { if (isReady != value) { isReady = value; RaisePropertyChanged(); } }
}
}
public sealed partial class MainPage : Page
{
public ObservableCollection<B> MyList { get; private set; } = new ObservableCollection<B>();
public MainPage()
{
this.InitializeComponent();
for (int i = 0; i < 10; i++)
{
MyList.Add(new B());
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
MyList[2].IsReady = !MyList[2].IsReady;
}
}
}
试验
下面是隐藏的代码:
<Page
x:Class="App1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App1"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<ListView ItemsSource="{x:Bind MyList}">
<ListView.ItemTemplate>
<DataTemplate x:DataType="local:B">
<UserControl>
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="group">
<VisualState x:Name="state1">
<VisualState.StateTriggers>
<StateTrigger IsActive="{x:Bind IsReady, Mode=OneWay}"/>
</VisualState.StateTriggers>
<Storyboard>
<ColorAnimation Duration="0:0:1.8" To="Red" Storyboard.TargetProperty="(Rectangle.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="rect" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Rectangle x:Name="rect" Fill="Blue" Width="20" Height="20" />
</Grid>
</UserControl>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Button Click="Button_Click">Test</Button>
</Grid>
</Page>
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
namespace App1
{
public abstract class NotifyPropertyChangedBase : INotifyPropertyChanged
{
protected NotifyPropertyChangedBase()
{
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void RaisePropertyChanged([CallerMemberName]string propertyName = null)
{
this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
public class B : NotifyPropertyChangedBase
{
private bool isReady;
public bool IsReady
{
get { return isReady; }
set { if (isReady != value) { isReady = value; RaisePropertyChanged(); } }
}
}
public sealed partial class MainPage : Page
{
public ObservableCollection<B> MyList { get; private set; } = new ObservableCollection<B>();
public MainPage()
{
this.InitializeComponent();
for (int i = 0; i < 10; i++)
{
MyList.Add(new B());
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
MyList[2].IsReady = !MyList[2].IsReady;
}
}
}
使用System.Collections.ObjectModel;
使用系统组件模型;
使用System.Runtime.CompilerServices;
使用Windows.UI.Xaml;
使用Windows.UI.Xaml.Controls;
名称空间App1
{
公共抽象类NotifyPropertyChangedBase:INotifyPropertyChanged
{
受保护的NotifyPropertyChangedBase()
{
}
公共事件属性更改事件处理程序属性更改;
受保护的虚拟void RaisePropertyChanged([CallerMemberName]字符串propertyName=null)
{
this.PropertyChanged?.Invoke(this,newpropertychangedeventargs(propertyName));
}
}
公共类B:NotifyPropertyChangedBase
{
私人住宅已准备就绪;
公共图书馆已经准备好了
{
获取{return isReady;}
设置{if(isReady!=value){isReady=value;RaisePropertyChanged();}}
}
}
公共密封部分类主页面:第页
{
public ObservableCollection MyList{get;private set;}=new ObservableCollection();
公共主页()
{
this.InitializeComponent();
对于(int i=0;i<10;i++)
{
添加(新的B());
}
}
私有无效按钮\u单击(对象发送者,路由目标e)
{
MyList[2]。IsReady=!MyList[2]。IsReady;
}
}
}
这里需要一个用户控件。如你所见,如果没有它,我们可能会出错。为了管理可视状态,我们需要一个子类,然而,它不是一个子类,而是继承自
视觉状态有时对于您想要更改UI中某个区域的状态(该区域不是立即的子类)的场景非常有用。不能直接执行此操作,因为该方法的控制参数需要一个子类,该子类引用VisualStateManager作用的对象
我们建议您将自定义定义为要应用状态的其他内容(例如)的根目录或容器。然后,您可以调用并应用状态,而不管其余内容是否为
有关更多信息,请参见的下的非控件元素的视觉状态。您的问题是什么?我用你的代码进行了测试,它在我这边运行得很好。@JayZuo MSFT,没有使用UserControl
,我在MainPage.g.cs中的Set\u Windows\u UI\u Xaml\u StateTrigger\u IsActive中得到了NullReferenceException