Question

我在ListView中有Button和Cell。当我单击单元格的按钮时，我要获取当前项目。

这是ListView

<ListView x:Name="list1" ItemsSource="{Binding StudentList}">
        <ListView.ItemTemplate>
        <DataTemplate>
            <ViewCell>
                <StackLayout>
                    <Image x:Name="Image1"  Source="other.png" />
                    <Label TextColor="{StaticResource mainColor}" 
                           Text="{Binding StudentName}" />
                    <Button x:Name="mybtn"                                
                    BindingContext="{Binding Source={x:Reference list1}, Path=BindingContext}" 
                    BackgroundColor="{DynamicResource CaribGreenPresent}"
                    Text="{Binding AttendanceTypeStatusIdGet, Converter={x:StaticResource IDToStringConverter}}">
                    </Button>
                </StackLayout>
            </ViewCell>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

当我单击mybtn时要在ViewModel中获取当前项目，该怎么做？

这是我的ViewModel代码

private List<Student> _studentList;
public List<Student> StudentList
{
    get { return _studentList; }
    set { SetProperty(ref _studentList, value); }
}

列出屏幕截图：

修改1： 在ViewModel中出现错误：

参数1：无法从“方法组”转换为“操作”

这是代码

//Constructor
public StudentAttendanceListPageViewModel(INavigationService _navigationService):base(_navigationService)
{
    ItemCommand=new DelegateCommand<Student>(BtnClicked);
}

public DelegateCommand<Student> ItemCommand { get; }
public void BtnClicked(object sender, EventArgs args)
{
    var btn = (Button)sender;
    var item = (Student)btn.CommandParameter;
    // now item points to the Student selected from the list
}

按钮XAML

<Button x:Name="mybtn"                                
BindingContext="{Binding Source={x:Reference list1}, Path=BindingContext}" 
Command="{Binding ItemCommand }" 
CommandParameter="{Binding Source={x:Reference mybtn}}"              
Text="{Binding AttendanceTypeStatusId, Converter={x:StaticResource IDToStringConverter}}">
</Button>

错误截图：

Answer 1

您可以通过命令绑定来做到这一点：

<Page x:Name="ThePage"
  ...>
  <ListView>
    <ListView.ItemTemplate>
      <DataTemplate>
        <ViewCell>
          ...
          <Button Command="{Binding Source={x:Reference ThePage}, Path=BindingContext.ItemCommand}"
                  CommandParameter="{Binding .}" />
        </ViewCell>
      </DataTemplate
    </ListView.ItemTemplate>
  </ListView>
</Page>

// Now in the VM...
ItemCommand = new DelegateCommand<Student>(ButtonClicked);
private void ButtonClicked(Student student)
{
  // Do something with the clicked student...
}

Answer 2

首先，请勿更改按钮的BindingContext

<Button Clicked="BtnClicked" CommandParameter="{Binding .}" ... />

然后在代码后面

protected void BtnClicked(object sender, EventArgs args)
{
  var btn = (Button)sender;
  var item = (Student)btn.CommandParameter;
  // now item points to the Student selected from the list
}

单击“单元格控件”之类的按钮时获取ListView项目

2 个答案: