我在Xamarin中遇到Android应用问题。我有MenuCardView.axml，其中MvxGridView与ItemSource在一起，但我不想在这里使用ItemClick。我要使用MvxBind单击MvxItemTemplate上的Button。但是Click在这里不起作用。
这是我的MenuCardView.axml：
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:local="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:stretchColumns="0">
<TableRow>
<LinearLayout
android:orientation="vertical"
android:layout_weight="1"
android:background="@color/white"
android:layout_width="match_parent"
android:layout_height="match_parent">
<MvxGridView
android:id="@+id/menuCardDetailGrid"
android:layout_weight="1"
android:background="@android:color/transparent"
local:MvxBind="ItemsSource MenuItems"
local:MvxItemTemplate="@layout/menucarddetailitemview"
android:numColumns="1"
android:verticalSpacing="5dp"
android:horizontalSpacing="5dp"
android:stretchMode="columnWidth"
android:gravity="center"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
android:choiceMode="singleChoice"
android:listSelector="@drawable/list_color_selector"
android:layout_width="match_parent"
android:layout_height="300dp"
android:layout_marginBottom="25dp" />
</LinearLayout>
</TableRow>
</TableLayout>
这是我的MenuCardDetailItemView.axml：
<?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:layout_width="match_parent"
android:layout_weight="1"
android:layout_height="match_parent"
android:background="@android:color/white"
android:orientation="vertical"
android:gravity="center_horizontal"
android:id="@+id/menucarddetailitemview">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_gravity="fill"
android:orientation="horizontal">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:layout_marginLeft="10dp">
<TextView
local:MvxBind="Text Name"
android:textSize="15dp"
android:layout_height="wrap_content"
android:textColor="@android:color/black"
android:layout_gravity="center_vertical"
android:lines="2"
android:maxLines="2"
android:layout_width="185dp" />
</LinearLayout>
<LinearLayout
android:layout_width="60dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center_horizontal">
<TextView
local:MvxBind="Text Price"
android:textSize="15dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@android:color/black"
android:layout_gravity="center_vertical" />
</LinearLayout>
<LinearLayout
android:layout_width="50dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center_horizontal"
android:layout_marginRight="10dp"
android:layout_marginLeft="10dp">
<Button
local:MvxBind="Click MenuItemClickCommand"
android:background="@color/red"
android:text="CLICK"
android:layout_width="60dp"
android:layout_height="20dp"
android:id="@+id/buttonMenuDetail"
android:layout_gravity="center_vertical"
android:textSize="13dp"
android:textColor="@color/white"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
</LinearLayout>
这是我的MenuCardViewModel.cs：
public class MenuCardViewModel : BaseViewModel
{
public MenuCardViewModel(IMvxMessenger messenger) : base(messenger)
{
}
public void Init(Menu menu)
{
Header = menu.Header;
InitializeMenuItems(menu);
}
private void InitializeMenuItems(Menu menu)
{
if (menu.MenuItemsList == null)
{
var offline = Mvx.Resolve<IOfflineContent>();
var loadedMenu = offline.GetMenuDetailFromApi(menu.Id);
MenuItems = loadedMenu.MenuItemsList;
}
else
{
MenuItems = menu.MenuItemsList;
}
}
private string _header;
public string Header
{
get { return _header; }
set
{
_header = value;
RaisePropertyChanged(() => Header);
}
}
private List<MenuItem> _menuItems;
public List<MenuItem> MenuItems
{
get { return _menuItems; }
set
{
_menuItems = value;
RaisePropertyChanged(() => MenuItems);
}
}
private ICommand _menuItemClickCommand;
public ICommand MenuItemClickCommand
{
get
{
_menuItemClickCommand = _menuItemClickCommand ?? new MvxCommand(DoMenuItemClickCommand);
return _menuItemClickCommand;
}
}
private void DoMenuItemClickCommand()
{
// code here...
}
}
我想在MenuCardVideDetailView的按钮上绑定MenuItemClickCommand。一些提示如何解决这个问题？
更新：
我试过了，但我不知道这是否是一个好的解决方案：
public class MenuCardViewModel : BaseViewModel
{
public MenuCardViewModel(IMvxMessenger messenger) : base(messenger)
{
}
public void Init(Menu menu)
{
Header = menu.Header;
InitializeMenuItems(menu);
}
private void InitializeMenuItems(Menu menu)
{
if (menu.MenuItemsList == null)
{
var offline = Mvx.Resolve<IOfflineContent>();
var loadedMenu = offline.GetMenuDetailFromApi(menu.Id);
//MenuItems = loadedMenu.MenuItemsList;
MenuItems = new List<MenuItemHolder>();
foreach(var item in loadedMenu.MenuItemsList)
{
MenuItems.Add(new MenuItemHolder(item, this));
}
}
else
{
//MenuItems = menu.MenuItemsList;
}
}
private string _header;
public string Header
{
get { return _header; }
set
{
_header = value;
RaisePropertyChanged(() => Header);
}
}
private List<MenuItemHolder> _menuItems;
public List<MenuItemHolder> MenuItems
{
get { return _menuItems; }
set
{
_menuItems = value;
RaisePropertyChanged(() => MenuItems);
}
}
}
public class MenuItemHolder
{
MenuCardViewModel _parent;
public int Id { get; set; }
private string _name;
public string Name
{
get { return _name; }
set
{
_name = value;
}
}
private string _price;
public string Price
{
get { return _price; }
set
{
_price = value;
}
}
public MenuItemHolder(MenuItem item, MenuCardViewModel parent)
{
_parent = parent;
Id = item.Id;
Name = item.Name;
Price = item.Price;
}
private ICommand _menuItemClickCommand;
public ICommand MenuItemClickCommand
{
get
{
_menuItemClickCommand = _menuItemClickCommand ?? new MvxCommand(DoMenuItemClickCommand);
return _menuItemClickCommand;
}
}
private void DoMenuItemClickCommand()
{
var item = this;
//here I can use BaseViewModel
_parent.Credit = 1337;
_parent.Bonus = 68;
}
}
}
最佳答案
MvxGridView ItemsSource绑定到作为MenuItems的List<MenuItem>，因此每个MvxItemTemplate都绑定到MenuItem。如果要将Button绑定到MenuItemClickCommand，则需要将该命令移至MenuItem类。
您无权访问子级中的父级DataContext。您可以实现一些方法，可以使用MvvmCross Messenger plugin进行通信并向父级请求一个对象。
要么
您可以将父项（MenuCardViewModel）包装在MenuItem中，如下所示：
public class MenuItem
{
MenuCardViewModel parent;
//// pass parent to menuItem
public MenuItem(MenuCardViewModel parent)
{
this.parent=parent;
}
public ICommand MenuItemClickCommand
{
get
{
return MvxCommand(() -> this.parent.DoMenuItemClickCommand(this));
}
}
}
并在
MenuCardViewModel中：public class MenuCardViewModel
{
....
public MenuCardViewModel(MenuItem menu)
{
/// do something
}
}
关于c# - MvxBind单击按钮在MvxGridView中不起作用，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41872637/