获取listview-Xamarin.forms中复选框选中项的计数

我有一个xamarin.forms应用程序，其中包含一个带有复选框的列表视图。单击按钮后，我可以获取列表视图中的复选框选中项。但我试图实现的是，当用户单击每个列表项上的复选框时，顶部的标签将显示已单击的复选框计数用于eg；已选中20个复选框中的11个。当用户选中或取消选中复选框时，如何实现此复选框选中的计数值

我的数据模型

  public class TimeSheetListData : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        public string EmployeeID { get; set; }         
        public string EndDate { get; set; }
        public string SlNo { get; set; }


    //Checkbox selection
        private bool selected;
        public bool Selected
        {

            get
            {
                return selected;
            }

            set
            {
                if (value != null)
                {
                    selected = value;
                    NotifyPropertyChanged("Selected");
                }
            }
        }
    }

    <StackLayout HorizontalOptions="FillAndExpand" Orientation="Vertical"> 
     // Where Iam trying to show count
 <Label x:Name="Count" Text="" FontSize="Small" TextColor="Black" VerticalOptions="Center" >
     <ListView  x:Name="TimesheetListView"  ItemsSource="{Binding} "                                                                   
                  HeightRequest="{Binding Path=Height, Source={x:Reference ListLayout}}"                      
                  BackgroundColor="Transparent" 
                  CachingStrategy="RecycleElement"
                  SeparatorVisibility="None"
                  HasUnevenRows="True"                       
                  HorizontalOptions="FillAndExpand"        
                  Margin="11,2,11,2"            
                  VerticalOptions="FillAndExpand">
                        <ListView.ItemTemplate>
                            <DataTemplate>
                                <ViewCell>
                                    <ViewCell.View>                                
                                     <Frame ClassId="{Binding EmployeeID}"  BorderColor="LightGray" >      
                                    <StackLayout HorizontalOptions="FillAndExpand" Orientation="Vertical">                               
                                     <Label Text="{Binding EndDate}" FontSize="Small" TextColor="Black" VerticalOptions="Center" >
                                                    </Label>
                                     <Label Text="{Binding SlNo}" FontSize="Small" TextColor="Black" VerticalOptions="Center" >
                                      </Label>
                                     <CheckBox x:Name="MultiSelectCheckBox" Grid.Column="2" Color="#004d6f" IsChecked="{Binding Selected}"  IsVisible="{Binding IsCheckBoxVisible}"  HorizontalOptions="End" VerticalOptions="Center"></CheckBox>
                                     </StackLayout>                                                
                                     </Frame>             
                                    </ViewCell.View>
                                </ViewCell>
                            </DataTemplate>
                        </ListView.ItemTemplate>
                    </ListView          
        </StackLayout>

我的xaml

  public class TimeSheetListData : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        public string EmployeeID { get; set; }         
        public string EndDate { get; set; }
        public string SlNo { get; set; }


    //Checkbox selection
        private bool selected;
        public bool Selected
        {

            get
            {
                return selected;
            }

            set
            {
                if (value != null)
                {
                    selected = value;
                    NotifyPropertyChanged("Selected");
                }
            }
        }
    }

    <StackLayout HorizontalOptions="FillAndExpand" Orientation="Vertical"> 
     // Where Iam trying to show count
 <Label x:Name="Count" Text="" FontSize="Small" TextColor="Black" VerticalOptions="Center" >
     <ListView  x:Name="TimesheetListView"  ItemsSource="{Binding} "                                                                   
                  HeightRequest="{Binding Path=Height, Source={x:Reference ListLayout}}"                      
                  BackgroundColor="Transparent" 
                  CachingStrategy="RecycleElement"
                  SeparatorVisibility="None"
                  HasUnevenRows="True"                       
                  HorizontalOptions="FillAndExpand"        
                  Margin="11,2,11,2"            
                  VerticalOptions="FillAndExpand">
                        <ListView.ItemTemplate>
                            <DataTemplate>
                                <ViewCell>
                                    <ViewCell.View>                                
                                     <Frame ClassId="{Binding EmployeeID}"  BorderColor="LightGray" >      
                                    <StackLayout HorizontalOptions="FillAndExpand" Orientation="Vertical">                               
                                     <Label Text="{Binding EndDate}" FontSize="Small" TextColor="Black" VerticalOptions="Center" >
                                                    </Label>
                                     <Label Text="{Binding SlNo}" FontSize="Small" TextColor="Black" VerticalOptions="Center" >
                                      </Label>
                                     <CheckBox x:Name="MultiSelectCheckBox" Grid.Column="2" Color="#004d6f" IsChecked="{Binding Selected}"  IsVisible="{Binding IsCheckBoxVisible}"  HorizontalOptions="End" VerticalOptions="Center"></CheckBox>
                                     </StackLayout>                                                
                                     </Frame>             
                                    </ViewCell.View>
                                </ViewCell>
                            </DataTemplate>
                        </ListView.ItemTemplate>
                    </ListView          
        </StackLayout>

//我想让你知道我在哪里
从列表的绑定源获取选中的列表项。。i、 e.如果项目来源是时间表列表

var totalSelectedItems = TimeSheetList.Where(t => t.Selected== true).Count();

另一个答案有一个漏洞：


由于您要从UI对模型进行更改，因此始终建议您使用双向绑定，否则UI的更改将永远不会反映在集合中。因此，您的复选框绑定如下所示

IsChecked="{Binding Selected, Mode=TwoWay}" // this reflects the changes from View to VM/Model.


一旦您这样做，您只需检查计数，如下所示：

var count = TimeSheetList.Count(t => t.Selected); //In case your Collection is a List

int count = TimeSheetList.Where(p => p.IsActiveUserControlChecked).Count; //If its an observable collection


这里的binding属性是什么
ItemsSource=“{binding}
？您可以使用它来获取计数。@AndroDevil请查看我的答案您可能会遇到当前的问题！！！！