xamarinform框架里前端用imagebutton里的Clicked事件取消任务，调用接口，如何写方法，
下面是我写的前端后端和接口，这个方法怎么写
前端： <StackLayout Spacing="5" Orientation="Horizontal" HorizontalOptions="Start">
<Label WidthRequest="65" FontAttributes="Bold" HorizontalTextAlignment="Center" BackgroundColor="Blue">起点</Label>
<Label WidthRequest="65" FontAttributes="Bold" HorizontalTextAlignment="Center" BackgroundColor="Blue">终点</Label>
<Label WidthRequest="70" FontAttributes="Bold" HorizontalTextAlignment="Center" BackgroundColor="Blue" >执行状态</Label>
<Label WidthRequest="70" FontAttributes="Bold" HorizontalTextAlignment="Center" BackgroundColor="Blue">取消任务</Label>
</StackLayout>
<StackLayout>
<ListView x:Name="lvAgvTask" ItemsSource="{Binding AgvTaskDataSource, Mode=OneWay}" CachingStrategy="RecycleElement" RowHeight="35" SelectionMode="None">
<!--Custom View Cells-->
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Spacing="5" VerticalOptions="Center">
<Label WidthRequest="65" Text="{Binding SaddrEx}" HorizontalTextAlignment="Center" FontSize="14" />
<Label ClassId="{Binding ID} " WidthRequest="65" Text="{Binding EaddrEx}" HorizontalTextAlignment="Center" FontSize="14"/>
<Label WidthRequest="70" Text="{Binding TaskStatus }" HorizontalTextAlignment="Center" FontSize="14"/>
<ImageButton Source="delete.jpeg" WidthRequest="50" HeightRequest="20" BackgroundColor="Green" Clicked="AgvTask_Delete"/>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</StackLayout>
接口名：CancelAgvTask
后台的clicked事件，怎么搞，这是我写的
private async void AgvTask_Delete(object sender, EventArgs e)
{
var result = new ResultEntity { ResultCode = 1 };
result = AgvApiHelper.CallEmiApi("CancelAgvTask", string.Empty, 1);
List<WMSTask> lstTask = JsonConvert.DeserializeObject<List<WMSTask>>(result.ResultMsg.ToString());

    }
}