MvvmCross绑定在Windows Phone参数命令 [英] MvvmCross bind command with parameter in Windows Phone

问题描述

我目前正在与Xamarin和MvvmCross一个简单的应用程序developped。
我有一个项目一个简单的列表，我想上的项目点击打开一个新的视角。

我能够做到，在与Android的：

这code视图的.axml

ListCustomersView.xaml

 ＆LT; MvxListView
        安卓了minWidth =25像素
        安卓了minHeight =25像素
        机器人：layout_width =match_parent
        机器人：layout_height =WRAP_CONTENT
        本地：MvxItemTemplate =@布局/ listcustomerscell
        本地：MvxBind =的ItemsSource ListCustomers;项目单击ShowCommand
        机器人：ID =@ + ID / listCustomersView/＆GT;
 

这code。在视图模型文件：

ListCustomersViewModel.cs

 私人MvxCommand＆LT; CustomerListDTO＆GT; _showCommand;
公众的ICommand ShowCommand
{
     {返回_showCommand？ （_showCommand =新Mv​​xCommand＆LT; CustomerListDTO＆GT;（C =＆GT; this.ShowCustomerDetail（C）））; }
}公共无效ShowCustomerDetail（CustomerListDTO C）
{
    ShowViewModel＆所述; CustomerDetailViewModel＆GT;（新CustomerDetailParameters（）{客户id = c.Id}）;
}
 

正如你所看到的，我通过命令传递一个参数：该CustomerDetailParameters类的一个实例。它的工作原理以及在Android中，但我不设法做，在Windows Phone的。

我米的ListCustomersView.xaml使用这种code：

 ＆LT;列表框名称=列表框的ItemsSource ={结合ListCustomers}＆GT;
        ＆LT; ListBox.ItemContainerStyle＆GT;
            ＆LT;风格的TargetType =ListBoxItem的＆GT;
                ＆LT; setter属性=Horizo​​ntalContentAlignmentVALUE =弹力/＆GT;
            ＆LT; /样式和GT;
        ＆LT; /ListBox.ItemContainerStyle>
        ＆LT; ListBox.ItemTemplate＆GT;
            ＆LT;＆DataTemplate的GT;
                ＆LT;控制：ListCustomersCell /＆GT;
            ＆LT; / DataTemplate中＆GT;
        ＆LT; /ListBox.ItemTemplate>
        ＆LT; I：Interaction.Triggers＆GT;
            ＆LT; I：的EventTrigger事件名称=的SelectionChanged＆GT;
                ＆LT; I：InvokeCommandAction命令={结合ShowCommand}/＆GT;
            ＆LT; /我：＆的EventTrigger GT;
        ＆LT; /我：Interaction.Triggers＆GT;
＆LT; /列表框＆GT;
 

该ShowCommand很好调用，但应该发送的CustomerListDTO为空。我想我没有使用好code。如果您有什么想法，我会带他们。

感谢您的帮助，有一个美好的一天！

解决方案

命令放慢参数是不是传递到命令

。试试下面code。通过传递CommandParameter到VM

  CommandParameter ={绑定的ElementName =列表框，路径=的SelectedItem}
 

i am currently working on a simple app developped with Xamarin and MvvmCross. I have a simple list of items and i want a click on an item open a new view.

I managed to do that in Android with :

this code in the .axml of the view

ListCustomersView.xaml

<MvxListView
        android:minWidth="25px"
        android:minHeight="25px"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        local:MvxItemTemplate="@layout/listcustomerscell"
        local:MvxBind="ItemsSource ListCustomers; ItemClick ShowCommand"
        android:id="@+id/listCustomersView" />

and this code in the ViewModel file :

ListCustomersViewModel.cs

private MvxCommand<CustomerListDTO> _showCommand;
public ICommand ShowCommand
{
     get { return _showCommand ?? (_showCommand = new MvxCommand<CustomerListDTO>(c => this.ShowCustomerDetail(c))); }
}

public void ShowCustomerDetail(CustomerListDTO c)
{
    ShowViewModel<CustomerDetailViewModel>(new CustomerDetailParameters() { CustomerID = c.Id });
}

As you can see, i send a parameter through the command : an instance of the CustomerDetailParameters class. It works well in Android, but i do not manage to do that in Windows Phone.

I m using this code in the ListCustomersView.xaml :

<ListBox Name="listBox" ItemsSource="{Binding ListCustomers}">
        <ListBox.ItemContainerStyle>
            <Style TargetType="ListBoxItem">
                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            </Style>
        </ListBox.ItemContainerStyle>
        <ListBox.ItemTemplate>
            <DataTemplate>
                <controls:ListCustomersCell />
            </DataTemplate>
        </ListBox.ItemTemplate>
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="SelectionChanged">
                <i:InvokeCommandAction Command="{Binding ShowCommand}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
</ListBox>

The ShowCommand is well called but the CustomerListDTO which should be sent is null. I imagine i am not using the good code. If you have any idea, i will take them.

Thanks for any help and have a good day !

解决方案

Command paramter is not passed to the command. Try below code by passing CommandParameter to the VM

CommandParameter="{Binding ElementName=listBox, Path=SelectedItem}

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