我在将Android.Support.V7.Widget.SwitchCompat绑定到我的视图模型时遇到麻烦（Mvvmcross是我正在使用的框架）
我所做的完全与另一个对象上的单击绑定完全一样，效果很好。
查看视图时出现的错误如下：
12-21 10:32:06.459 I/MvxBind (22969): 42,82 Failed to create target binding for binding CheckedChange for OnCheckedChanged
[0:] MvxBind:Warning: 42,82 Failed to create target binding for binding CheckedChange for OnCheckedChanged
多次开关我有。
他们说，由于反射魔术的原因，它可能必须对链接器做一些不包括其他内容的操作。
他们说，您必须创建一个文件“ LinkerPleaseInclude”以保留对switchcompat的引用。我这样做如下，但错误仍然存在。
链接器请包括
class LinkerPleaseInclude
{
public void Include(TextView text)
{
text.AfterTextChanged += (sender, args) => text.Text = "" + text.Text;
text.Hint = "" + text.Hint;
}
public void Include(CompoundButton cb)
{
cb.CheckedChange += (sender, args) => cb.Checked = !cb.Checked;
cb.Hint = "" + cb.Hint;
}
public void Include(SwitchCompat cb)
{
cb.CheckedChange += (sender, args) => cb.Checked = !cb.Checked;
cb.Hint = "" + cb.Hint;
}
public void Include(ICommand command)
{
command.CanExecuteChanged += (s, e) => { if (command.CanExecute(null)) command.Execute(null); };
}
public void Include(CheckBox checkBox)
{
checkBox.CheckedChange += (sender, args) => checkBox.Checked = !checkBox.Checked;
}
}
我的ViewLayout：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:local="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="@dimen/md_list_single_line_item_height"
android:gravity="center_vertical"
android:paddingLeft="@dimen/md_list_item_horizontal_edges_padding"
android:paddingRight="@dimen/md_list_item_horizontal_edges_padding">
<android.support.v7.widget.SwitchCompat
android:id="@+id/mySwitch"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
local:MvxBind="Checked IsActive; Click OnSwitchClick; CheckedChange OnCheckedChanged" />
<TextView
android:id="@+id/Name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:textColor="@color/md_text_dark_primary_87"
android:textSize="@dimen/md_list_item_primary_text"
local:MvxBind="Text Name"/>
<TextView
android:id="@+id/Kind"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:textColor="@color/md_text_dark_secondary_54"
android:textSize="@dimen/md_list_item_secondary_text"
android:layout_below="@+id/Name"
local:MvxBind="Text Kind"/>
</RelativeLayout>
此布局是其他布局的子级：
<?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="vertical"
android:layout_width="match_parent"
android:layout_height="@dimen/md_list_two_line_item_height"
android:paddingTop="?android:attr/actionBarSize"
android:fitsSystemWindows="true">
<MvxClickableLinearLayout
android:id="@+id/animalSelectionsList"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:divider="@drawable/divider_horizontal"
android:showDividers="middle"
local:MvxBind="ItemsSource SelectionsList"
local:MvxItemTemplate="@layout/listitem_animal_selections" />
</LinearLayout>
最佳答案
CheckedChange是事件，因此不是公共财产。您不能直接在MvvmCross中绑定事件，除非您创建自己的目标绑定来处理该事件并公开一个Command。
看起来可能像这样：
public class MvxCompoundButtonCheckedChangeBinding : MvxAndroidTargetBinding
{
private ICommand _command;
private IDisposable _checkedChangeSubscription;
private IDisposable _canExecuteSubscription;
private readonly EventHandler<EventArgs> _canExecuteEventHandler;
protected CompoundButton View => (CompoundButton)Target;
public MvxCompoundButtonCheckedChangeBinding(CompoundButton view)
: base(view)
{
_canExecuteEventHandler = OnCanExecuteChanged;
_checkedChangeSubscription = view.WeakSubscribe<CompoundButton, CompoundButton.CheckedChangeEventArgs>(nameof(view.CheckedChange), ViewOnCheckedChangeClick);
}
private void ViewOnCheckedChangeClick(object sender, CompoundButton.CheckedChangeEventArgs args)
{
if (_command == null)
return;
if (!_command.CanExecute(null))
return;
_command.Execute(view.Checked);
}
protected override void SetValueImpl(object target, object value)
{
_canExecuteSubscription?.Dispose();
_canExecuteSubscription = null;
_command = value as ICommand;
if (_command != null)
{
_canExecuteSubscription = _command.WeakSubscribe(_canExecuteEventHandler);
}
RefreshEnabledState();
}
private void RefreshEnabledState()
{
var view = View;
if (view == null)
return;
var shouldBeEnabled = false;
if (_command != null)
{
shouldBeEnabled = _command.CanExecute(null);
}
view.Enabled = shouldBeEnabled;
}
private void OnCanExecuteChanged(object sender, EventArgs e)
{
RefreshEnabledState();
}
public override MvxBindingMode DefaultMode => MvxBindingMode.OneWay;
public override Type TargetType => typeof(ICommand);
protected override void Dispose(bool isDisposing)
{
if (isDisposing)
{
_checkedChangeSubscription?.Dispose();
_checkedChangeSubscription = null;
_canExecuteSubscription?.Dispose();
_canExecuteSubscription = null;
}
base.Dispose(isDisposing);
}
}
然后，您需要在您的Setup.cs中以
FillTargetFactories替代方式进行注册：registry.RegisterCustomBindingFactory<View>("MyCheckedChange",
view => new MvxCompoundButtonCheckedChangeBinding(view));
然后，您可以将MyCheckedChange绑定到您的命令。
关于android - MvxBind CheckedChange SwitchCompat，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41259474/