从usercontrol发送（或绑定参数）到WPF MVVM中的另一个用户控件 [英] Send (or bind parameters) from a usercontrol to another usercontrol in WPF MVVM

问题描述

我们用户MVVM模型，有一个UserControl，它有一个ItemControl，在ItemTemlate中有一个usercontrol（usercontrol2），如下所示：

We user MVVM Model, There is a UserControl that has a ItemControl which in ItemTemlate a usercontrol (usercontrol2) is located, like this:

<UserControl x:Class="usercontrol1">

...

< ItemsControl ItemsSource =" {Binding GroupsList}" ">

<ItemsControl ItemsSource="{Binding GroupsList}" ">

...

< ItemsControl.ItemTemplate>&NBSP;

<ItemsControl.ItemTemplate> 

<的DataTemplate>&NBSP;

<DataTemplate> 

< span style ="white-space：pre"> < local：usercontrol2  /> 

<local:usercontrol2  /> 

< / DataTemplate> 

</DataTemplate> 

< /ItemsControl.ItemTemplate> 

</ItemsControl.ItemTemplate> 

< / ItemsControl>

</ItemsControl>

< / UserControl>

</UserControl>

我们将发送（或使用绑定）参数GroupNumber（GroupList的属性） 从  usercontrol1到usercontrol2，怎么做？

we are going to to sent (or using binding) parameter GroupNumber ( a propery of GroupList)  from usercontrol1 to usercontrol2,How can do that?

推荐答案

默认情况下， UserControl 的 DataContext 是从其父
除非您指定其他数据源。

In default, the DataContext of UserControl is inherited from its parent unless you specify another data source.

所以 如果
GroupNumber 是
GroupsList的项目，您可以直接绑定它。

So if the GroupNumber  is a property of GroupsList's Item, you can bind it directly.

我做了一个样本供你参考。

I made a sample for your reference.

MainWindow：

MainWindow:

<Window x:Class="wpfAppDemo.wpfTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:wpfAppDemo.wpfTest"
        mc:Ignorable="d"
       x:Name="mainwindow"
        Title="MainWindow" Height="300" Width="800">
    <StackPanel x:Name="rootGrid" DataContext="{Binding ElementName=mainwindow}">      
        <local:UserControl1/>
    </StackPanel>
</Window>

In 代码背后，我有一个GroupItem列表，它有两个名为  GroupName和GroupNumber的属性。

In  Code behind , I have a list of GroupItem which have two properties named  GroupName and GroupNumber.

namespace wpfAppDemo.wpfTest
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public ObservableCollection<GroupItem> GroupList { get; set; }

        public MainWindow()
        {
            InitializeComponent();

            GroupList = new ObservableCollection<GroupItem> {
                new GroupItem { GroupName="Bob", GroupNumber=7 },
                new GroupItem { GroupName ="Emily", GroupNumber=7 },
                new GroupItem { GroupName ="James", GroupNumber=8 },};
        }
    }

    public class GroupItem
    {
        public string GroupName { get; set; }

        public int GroupNumber { get; set; }
    }
}

$

UserControl1：

UserControl1:

<UserControl
    x:Class="wpfAppDemo.wpfTest.UserControl1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:wpfAppDemo.wpfTest"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    d:DesignHeight="300"
    d:DesignWidth="300"
    mc:Ignorable="d">
    <StackPanel>
        <TextBlock Text="this is user control 1" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="20"/>
        <ItemsControl  
            Background="#E4CECE"
            ItemsSource="{Binding Path=GroupList}">
            <ItemsControl.ItemTemplate>
                <DataTemplate DataType="{x:Type GroupItem}">
                    <StackPanel Orientation="Horizontal">
                        <TextBlock
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center"
                            FontSize="20"
                            Margin="0,0,5,0"
                            Text="{Binding GroupName}" />
                        <TextBlock
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center"
                            FontSize="20"
                            Margin="0,0,10,0"
                            Text=":" />
                        <TextBlock
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center"
                            FontSize="20"
                            Margin="0,0,10,0"
                            Text="{Binding GroupNumber}" />
                        <local:UserControl2 />
                    </StackPanel>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </StackPanel>
</UserControl>

在UserControl2中：

In UserControl2:

<UserControl
    x:Class="wpfAppDemo.wpfTest.UserControl2"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:wpfAppDemo.wpfTest"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    d:DesignHeight="100"
    d:DesignWidth="300"
    x:Name="uc1"
    Background="Transparent"
    mc:Ignorable="d">
    <Border
        Padding="0"
        Background="#C69A9A"
        BorderBrush="Black"
        BorderThickness="1"
        CornerRadius="8">
        <StackPanel
            Margin="10"
            AllowDrop="True"
            Background="AntiqueWhite" >    
           <TextBlock Text="this is user control 2" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="20"/>          
            <TextBlock Text="{Binding GroupNumber}" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="20"/>
        </StackPanel>
    </Border>
</UserControl>

此致，

鲍勃

Bob

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