Obter ligação da classe view
Eu tenho uma classe CustomView com um layout de banco de dados que aceita uma variável. No layout que contém o CustomView, desejo passar um atributo para o CustomView e fazer com que o CustomView passe esse atributo na ligação do seu próprio layout. Aqui está o que eu tenho:
public class CustomView extends LinearLayout
{
public CustomView(Context inContext, AttributeSet inAttrs)
{
super(inContext, inAttrs);
inflate(inContext, R.layout.custom_view, null);
}
@BindingAdapter({"app:variable"})
public static void SetVariable(CustomView inCustomView, VariableType inMyVariable)
{
CustomViewBinding binding = DataBindingUtil.getBinding(inCustomView);
binding.setMyVariable(inMyVariable);
}
}
Isso trava ao tentar extrair a ligação da exibição. Isso é possível? Aqui está o rastreamento de pilha:
java.lang.NullPointerException: Attempt to invoke virtual method 'void xxx.databinding.CustomViewBinding.setVariableType(xxx.VariableType)' on a null object reference
at xxx.CustomView.SetDynamicList(CustomView.java:32)
at xxx.MyFragmentBinding.executeBindings(MyFragmentBinding.java:116)
at android.databinding.ViewDataBinding.executePendingBindings(ViewDataBinding.java:350)
at android.databinding.ViewDataBinding$6.run(ViewDataBinding.java:167)
at android.databinding.ViewDataBinding$7.doFrame(ViewDataBinding.java:233)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:856)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:603)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
E se eu mudar
DataBindingUtil.getBinding(inCustomView)
para
DataBindingUtil.bind(inCustomView)
então eu entendi:
java.lang.IllegalArgumentException: View is not a binding layout
at android.databinding.DataBindingUtil.bind(DataBindingUtil.java:166)
at android.databinding.DataBindingUtil.bind(DataBindingUtil.java:140)
at xxx.CustomView.SetDynamicList(CustomView.java:30)
- at xxx.databinding.MyFragmentBinding.executeBindings(MyFragmentBinding.java:116)
at android.databinding.ViewDataBinding.executePendingBindings(ViewDataBinding.java:350)
at android.databinding.ViewDataBinding$6.run(ViewDataBinding.java:167)
at android.databinding.ViewDataBinding$7.doFrame(ViewDataBinding.java:233)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:856)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:603)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Isso pode implicar que o arquivo de layout não esteja formatado para ligação de dados, mas sim. Ele tem o elemento de layout e o elemento de dados com variáveis e tudo.