将命令绑定到视图的Loaded事件

Question

我正在尝试在视图加载完成后运行一个方法。我尝试将一个命令绑定到视图中的Loaded事件，但它无法运行。抛出的内部异常是

"在"System.Windows.Data.Binding"上提供值引发了异常。"行号"14"和行位置"14"

<UserControl x:Class="Components.Map.MapView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:map="clr-namespace:Components.Map"
             xmlns:controls="clr-namespace:Windows.Controls;assembly=Windows.Controls"
             xmlns:ValidationRules="clr-namespace:Windows.Controls.ValidationRules;assembly=Windows.Controls"
             xmlns:directGraphicsControl="clr-namespace:Windows.DirectGraphicsControl;assembly=Windows.DirectGraphicsControl"
             xmlns:colorBar="clr-namespace:Components.Common.ColorBar;assembly=Components.Common"
             xmlns:RefinedRibbonControls="clr-namespace:Components.Common.Controls.RefinedRibbonControls;assembly=Components.Common"
             xmlns:UserControls="clr-namespace:Components.Common.UserControls;assembly=Components.Common"
             xmlns:map1="clr-namespace:Models.Map;assembly=Models.Map"
             xmlns:utilities="clr-namespace:Windows.Utilities;assembly=Windows.Utilities"
             xmlns:system="clr-namespace:System;assembly=mscorlib"
             Loaded="{Binding Path=MapControlViewModel.MapLoadedCommand}">

如何绑定到视图；s的Loaded事件，以便在视图加载完成后运行某些内容？

Answer 1

如果要将命令绑定到Loaded事件，则应使用"System.Windows.Interactive"程序集。

<UserControl x:Class="Components.Map.MapView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:map="clr-namespace:Components.Map"
             xmlns:controls="clr-namespace:Windows.Controls;assembly=Windows.Controls"
             xmlns:ValidationRules="clr-namespace:Windows.Controls.ValidationRules;assembly=Windows.Controls"
             xmlns:directGraphicsControl="clr-namespace:Windows.DirectGraphicsControl;assembly=Windows.DirectGraphicsControl"
             xmlns:colorBar="clr-namespace:Components.Common.ColorBar;assembly=Components.Common"
             xmlns:RefinedRibbonControls="clr-namespace:Components.Common.Controls.RefinedRibbonControls;assembly=Components.Common"
             xmlns:UserControls="clr-namespace:Components.Common.UserControls;assembly=Components.Common"
             xmlns:map1="clr-namespace:Models.Map;assembly=Models.Map"
             xmlns:utilities="clr-namespace:Windows.Utilities;assembly=Windows.Utilities"
             xmlns:system="clr-namespace:System;assembly=mscorlib"
             xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity">
             <i:Interaction.Triggers>
                <i:EventTrigger EventName="Loaded">
                    <i:InvokeCommandAction Command="{Binding LoadedCommand}" />
                </i:EventTrigger>
            </i:Interaction.Triggers>
</UserControl>

System.Windows.Interactivity.dll位于Microsoft Expression Blend软件开发工具包（SDK）（下载链接）中，也可以作为NuGet包提供。

Answer 2

1. 安装nuget包Microsoft.Xaml.Behaviors.Wpf（不赞成使用System.Windows.Interactivity）

2. 将xmlns添加到窗口/用户控件中。xmlns:b="http://schemas.microsoft.com/xaml/behaviors"

3. 将触发器添加到主窗口

    <b:Interaction.Triggers>
        <b:EventTrigger EventName="Loaded">
            <b:InvokeCommandAction
                CommandParameter="{Binding}"
                Command="{Binding MyLoadedCommand}"/>
        </b:EventTrigger>
    </b:Interaction.Triggers>