Question

我有index.php，它使用recyclerview将所有人显示为列表。每个人都有年龄，性别，姓名属性以及复选框以便删除它。

我无法弄清楚如何在MainViewModel中捕获用户复选框事件？

MainView.axml

MainViewModel

PersonTemplate.axml

    <CheckBox
      android:id="@+id/checkbox"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1"
      local:MvxBind="Checked IsAllSelected" />

    <TextView
      android:layout_width="0dp"
      android:layout_weight="1"
      android:layout_height="wrap_content"
      android:text="Name"
      android:layout_weight="1" />

    <TextView
      android:layout_width="0dp"
      android:layout_weight="1"
      android:layout_height="wrap_content"
      android:text="Age" />

    <TextView
      android:layout_width="0dp"
      android:layout_weight="1"
      android:layout_height="wrap_content"
      android:text="Gender" />
 </LinearLayout>

 <MvxRecyclerView
    android:id="@+id/personRecyclerView"
    android:scrollbars="vertical"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    local:MvxItemTemplate="@layout/persontemplate"
    local:MvxBind="ItemsSource Items; ItemClick ItemSelected" />
 </LinearLayout>

我正在尝试根据每个项目的<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:local="http://schemas.android.com/apk/res-auto" android:orientation="horizontal" android:layout_width="match_parent" android:gravity="center_vertical" android:layout_height="60dp"> <CheckBox android:id="@+id/chked" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" local:MvxBind="Checked IsSelected; Click CheckBoxSelectionCommand;" /> <TextView android:id="@+id/Name" android:layout_width="0dp" android:layout_height="wrap_content" local:MvxBind="Text Name" android:layout_weight="1" /> <TextView android:id="@+id/Age" android:layout_width="0dp" android:layout_height="wrap_content" local:MvxBind="Text Age" android:layout_weight="1" /> <TextView android:id="@+id/Gender" android:layout_width="0dp" android:layout_height="wrap_content" local:MvxBind="Text Gender android:layout_weight="1" /> </LinearLayout>选项更新IsDeleteBtnShow。

MainViewModel.cs

checkbox

我有以下viewmodel，public bool IsAllSelected { get { return _isAllSelected; } set { _isAllSelected= value; Items.ForEach(x => x.IsSelected = _isAllSelected); IsDeleteBtnShow = _isAllSelected; RaisePropertyChanged(() => IsAllSelected); } }用来将人员列表为列表。

PersonRecyclerViewModel.cs

RecyclerView

Answer 1

您可以将回调或命令传递给ItemViewModel的cration。 CreateViewModel(Person person, Action<PersonViewModel> checkboxSelectedCallback)并将其直接用作CheckBoxSelectionCommand或public ICommand CheckBoxSelectionCommand { get { return new MvxCommand(() => { var isChecked = IsSelected; ParentCheckBoxSelectionCallback(this); }); } }。像这样：

<强> CheckBoxSelectionCommand

public static PersonViewModel CreateViewModel(Person person, Action<PersonViewModel> checkboxSelectedCallback)
{
    return new PersonViewModel 
    {
        IsSelected = entity.IsSelected,
        Age = entity.Age,
        ParentCheckBoxSelectionCallback = checkboxSelectedCallback,
        Gender= entity.Gender,
        Name= entity.Name,
    };
}

<强> CreateViewModel

// only create once. 
_checkedChangedCallback = (person =>  
{
    // do what you have to do if a item got selected
});

// where you create persons
CreateViewModel(person, _checkedChangedCallback );

<强> MainViewModel

usort

Answer 2

如果不在模型中添加操作或任何逻辑，另一种方法是使模型实现 INotifyPropertyChanged ：

class PersonRecyclerViewModel : INotifyPropertyChanged

最快捷的方法是使用Fody PropertyChanged，因为只需在模型中添加属性即可获得界面的整个实现：

[ImplementPropertyChanged]
class PersonRecyclerViewModel {}

在ViewModel中，当您获取或刷新数据源时，for循环将侦听项属性更改：

foreach(var item in Items)
{
    var n = (INotifyPropertyChanged)item;
    n.PropertyChanged += OnItemPropertyChanged;
}

private void OnItemPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)
{
    if(propertyChangedEventArgs.PropertyName == "IsSelected")
    {
       // do whatever you need here
    }
}

在recyclerview中捕获复选框事件

2 个答案: