Question

我想使用数组在strings.xml RecycleView中显示来自multi ViewHolder的数据，当我显示不包含array的数据时可以，但是如果我使用{{1 }}，我在数组代码中出现错误。不幸的是，该应用程序已停止。 array是：

logcat

您能解决这个问题吗？

DoaPagi.java

07-27 23:49:58.466 8159-8159/com.alexzh.tutorial.multiplerowlayoutsrecyclerview E/AndroidRuntime: FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.alexzh.tutorial.multiplerowlayoutsrecyclerview/com.alexzh.tutorial.multiplerowlayoutsrecyclerview.DoaSore}: java.lang.NullPointerException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
        at android.app.ActivityThread.access$600(ActivityThread.java:141)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:5103)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:525)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
        at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
        at com.alexzh.tutorial.multiplerowlayoutsrecyclerview.DoaPagi.getData(DoaPagi.java:40)
        at com.alexzh.tutorial.multiplerowlayoutsrecyclerview.DoaSore.onStart(DoaSore.java:28)
        at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1171)
        at android.app.Activity.performStart(Activity.java:5143)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
        at android.app.ActivityThread.access$600(ActivityThread.java:141) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:137) 
        at android.app.ActivityThread.main(ActivityThread.java:5103) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:525) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
        at dalvik.system.NativeStart.main(Native Method) 
07-27 23:54:58.846 8159-8159/? I/Process: Sending signal. PID: 8159 SIG: 9

AdapterDoa.java

public class DoaPagi extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_doa_pagi);

}

@Override
protected void onStart() {
    super.onStart();

    AdapterDoa adapter = new AdapterDoa(DoaPagi.getData());

    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(DoaPagi.this);
    RecyclerView mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
    mRecyclerView.setLayoutManager(linearLayoutManager);
    mRecyclerView.setItemAnimator(new DefaultItemAnimator());
    mRecyclerView.setAdapter(adapter);
}

public static Context context;
public static List<ModelDoa> getData() {

    String[] data = context.getResources().getStringArray(R.array.doasore);

    List<ModelDoa> list = new ArrayList<>();

    list.add(new ModelDoa("London", ModelDoa.DOA_PAGI));
    list.add(new ModelDoa("Amsterdam", ModelDoa.DOA_PAGI));
    list.add(new ModelDoa("Berlin", ModelDoa.DOA_PAGI));

    // error code is here
    for (int i = 0; i < data.length; i++) {
        list.add(new ModelDoa(data[i], ModelDoa.DOA_PAGI));
    }

    return list;
}


}

PagiViewHolder.java

public class AdapterDoa extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

private List<ModelDoa> mList;

public AdapterDoa(List<ModelDoa> list) {

    this.mList = list;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    switch (viewType) {

        case DOA_PAGI:
            View vieu = LayoutInflater.from(parent.getContext()).inflate(R.layout.content_doa, parent, false);
            PagiViewHolder rcv = new PagiViewHolder(vieu);
            return rcv;

        case DOA_SORE:
            View doa = LayoutInflater.from(parent.getContext()).inflate(R.layout.content_doa, parent, false);
            SoreViewHolder mdoa = new SoreViewHolder(doa);
            return mdoa;
    }
    return null;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

    ModelDoa object = mList.get(position);

    if (object != null) {

        switch (object.getType()) {

            case DOA_PAGI:
                ((PagiViewHolder) holder).mTitle.setText(object.getName());
                break;

            case DOA_SORE:
                ((SoreViewHolder) holder).mTitle.setText(object.getName());
                break;
        }
    }
}

@Override
public int getItemCount() {
    if (mList == null)
        return 0;
    return mList.size();
}

@Override
public int getItemViewType(int position) {
    if (mList != null) {
        ModelDoa object = mList.get(position);
        if (object != null) {
            return object.getType();
        }
    }
    return 0;
}


}

Answer 1

我相信问题出在这里：

String[] data = context.getResources().getStringArray(R.array.doasore);

您正在使用context的{{1}}变量，因为尚未初始化。一种可能的解决方案如下：

null

Answer 2

将上面的代码更改为下面的代码，就可以了：

public static List<ModelDoa> getData() {

String[] data = getResources().getStringArray(R.array.doasore);

List<ModelDoa> list = new ArrayList<>();

list.add(new ModelDoa("London", ModelDoa.DOA_PAGI));
list.add(new ModelDoa("Amsterdam", ModelDoa.DOA_PAGI));
list.add(new ModelDoa("Berlin", ModelDoa.DOA_PAGI));

// error code is here
for (int i = 0; i < data.length; i++) {
    list.add(new ModelDoa(data[i], ModelDoa.DOA_PAGI));
}

return list; }

如何在RecycleView Multi ViewHolder中使用数组显示数据？

2 个答案: