如何显示对话框片段从ImageView onClick在回收视图适配器

Question

我有ActionBarDialog（DialogFragment），CarAdapter（RecycleView）和SportFragment。我在SportFragment中创建方法（infoMethod）以显示DialogFragment并正常工作。但是，如果我想调用infoMethod在CarAdapter是不行的（显示java.lang.NullPointerException）

infoMethod在SportFragment

public void infoMethod(){ 
    Bundle args = new Bundle(); 
    args.putString("title", "Dialog with Action Bar"); 
    ActionBarDialog actionbarDialog = new ActionBarDialog(); 
    actionbarDialog.setArguments(args); 
    actionbarDialog.show(getActivity().getSupportFragmentManager(), 
      "action_bar_frag"); 
} 

我尝试从CarAdapter

 public MyViewHolder(View view) { 
     super(view); 

     image= (ImageView) view.findViewById(R.id.imageViewlist); 
     image.setOnClickListener(this); 

    } 
    @Override 
    public void onClick(View v) { 
     SportFragment infoFrag = new SportFragment(); 
     if (v.getId() == image.getId()){ 
      v.startAnimation(AnimationUtils.loadAnimation(v.getContext(), R.anim.imagelist)); 
      infoFrag.infoMethod(); //call infoMethod not work 

      Toast.makeText(v.getContext(), "ITEM PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show(); 
     } else { 
      Toast.makeText(v.getContext(), "ROW PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show(); 
     } 
    } 

logcat的

调用infoMethod

09-29 13:30:09.292 18661-18661/com.paijostudio.hitungmasa E/AndroidRuntime: FATAL EXCEPTION: main 
                      java.lang.NullPointerException 
                       at com.paijostudio.hitungmasa.fragment.SportFragment.infoMethod(SportFragment.java:210) 
                       at com.paijostudio.hitungmasa.adapter.CarAdapter$MyViewHolder.onClick(CarAdapter.java:73) 
                       at android.view.View.performClick(View.java:4204) 
                       at android.view.View$PerformClick.run(View.java:17355) 
                       at android.os.Handler.handleCallback(Handler.java:725) 
                       at android.os.Handler.dispatchMessage(Handler.java:92) 
                       at android.os.Looper.loop(Looper.java:137) 
                       at android.app.ActivityThread.main(ActivityThread.java:5041) 
                       at java.lang.reflect.Method.invokeNative(Native Method) 
                       at java.lang.reflect.Method.invoke(Method.java:511) 
                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
                       at dalvik.system.NativeStart.main(Native Method) 

任何解决方案显示DialogFragment？谢谢

Answer 1

似乎

infoFrag.infoMethod(); //call infoMethod not work 

确实不工作，因为@SunnySydeUp可能是正确的。也许尝试为

显示java.lang.NullPointerException 在com.paijostudio.hitungmasa.fragment.SportFragment.infoMethod在前面加了行号（SportFragment.java:210）

是非常具体的关于它。你试图对一些空的东西做些什么。从这里发生的事情看，这很可能是SportFragment。

我的建议是为了调试而分解。所以我会移动方法

public void infoMethod(){ 

SportFragment之外。并将其移动到类

CarAdapter 

这意味着SportFragment可以为null。只要检查一下是否有效。如果是这样，那就是我所期望的，你必须在创建SportFragment时解决这个问题。一旦解决了问题，您可以将方法移回原处。寻找获取，或在Android文档中创建Fragments。

https://developer.android.com/guide/components/fragments.html

UPDATE： 作为补充和接收的详细信息。由于SportFragment创建不正确，碎片没有附加任何活动。

看一看下面的答案正确传达给你的片段 How to create interface between Fragment and adapter?

Answer 2

既然你想在应用中创建两个独立的区域对话，我建议把它出它自己的类

public class DialogHelper { 
    public static void infoMethod(FragmentManager fragmentManager) { 
     Bundle args = new Bundle(); 
     args.putString("title", "Dialog with Action Bar"); 
     ActionBarDialog actionbarDialog = new ActionBarDialog(); 
     actionbarDialog.setArguments(args); 
     actionbarDialog.show(fragmentManager, "action_bar_frag"); 
    } 
} 

然后在SportFragment更换DialogHelper.infoMethod(getActivity().getSupportFragmentManager());

至于你的电话你CarAdapter，你需要参加一个FragmentManager。

recyclerView.setAdapter(new CarAdapter(getActivity().getSupportFragmentManager())) 

... 

public class CarAdapter extends RecyclerView.Adapter<MyViewHolder> { 
    private FragmentManager fragmentManager; 

    public CarAdapter(FragmentManager fragmentManager) { 
     this.fragmentManager = fragmentManager; 
    } 

    public class MyViewHolder { 
     ... 

     @Override 
     public void onClick(View v) { 
      if (v.getId() == image.getId()){ 
       v.startAnimation(AnimationUtils.loadAnimation(v.getContext(), R.anim.imagelist)); 
       DialogHelper.infoMethod(fragmentManager); 

       Toast.makeText(v.getContext(), "ITEM PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show(); 
      } else { 
       Toast.makeText(v.getContext(), "ROW PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show(); 
      } 
     } 
    } 
}