Question

我正在将数据从Json对象设置为MyData类，并添加到ArrayList，并希望将此ArrayList发送到另一个Activity，以在RecyclerView上显示数据。 / p>

我尝试使用parcelable，但它对我不起作用。

public class MyData implements Parcelable {

    private String name,password;

    public MyData() {
        this.name = name;
        this.password = password;
    }
 public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

protected MyData(Parcel in) {
    name = in.readString();
    password = in.readString();
}

public static final Creator<MyData> CREATOR = new Creator<MyData>() {
    @Override
    public MyData createFromParcel(Parcel in) {
        return new MyData(in);
    }

    @Override
    public MyData[] newArray(int size) {
        return new MyData[size];
    }
};



@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeString(name);
    dest.writeString(password);
}

}

Mydata Calss的此部分与Getter和Setter一起

class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {

private Context context;
private List<MyData> myData;

public CustomAdapter(Context context, List<MyData> myData) {
    this.context = context;
    this.myData = myData;
}

@NonNull
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int i) {

    View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_inflater, parent, false);

    return new ViewHolder(itemView);

}

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

    holder.name.setText(myData.get(position).getName());
    holder.pass.setText(myData.get(position).getPassword());

}

@Override
public int getItemCount() {
    return myData.size();
}


public class ViewHolder extends RecyclerView.ViewHolder {

    TextView name,pass;


    public ViewHolder(View itemView) {
        super(itemView);
        name = (TextView) itemView.findViewById(R.id.name_txt);
        pass = (TextView) itemView.findViewById(R.id.pass_txt);
    }
}

} //我的适配器Plz Hlep

MainActivity1

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


    data_list = new ArrayList<>();




}



public void GoOnClick(View view) {

    load_from_data();

    Intent intent = new Intent(MainActivity.this , Main2Activity.class);
    Bundle bundle = new Bundle();
    bundle.putParcelableArrayList("key", (ArrayList<? extends Parcelable>) data_list);
    intent.putExtras(bundle);
    startActivity(intent);


}



 private void load_from_data() 
{

        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST, get_info_url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {

                    JSONArray jsonArray = response.getJSONArray("users");

                    for (int i = 0 ; i < jsonArray.length() ; i++)
                    {
                        JSONObject users = jsonArray.getJSONObject(i);
                        MyData myData = new MyData();

                        myData.setName(users.getString("name"));
                        myData.setPassword(users.getString("password"));

                        data_list.add(myData);

                    }



                } catch (Exception e) {}



            }

        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        });

        //setrecyclerview(data_list);
        requestQueue = Volley.newRequestQueue(MainActivity.this);
        requestQueue.add(jsonObjectRequest);

    }

//获取Json Object数据的方法

MainActivity2

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);

    mainList = new ArrayList<>();
    mainList = this.getIntent().getExtras().getParcelableArrayList("key");
    setrecyclerview(mainList);

}

private void setrecyclerview(List<MyData> data_list) {

    CustomAdapter adapter = new CustomAdapter(this, data_list);
    DividerItemDecoration divider = new DividerItemDecoration(recyclerView.getContext(), new LinearLayoutManager(this).getOrientation());
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.addItemDecoration(divider);
    recyclerView.setHasFixedSize(true);
    recyclerView.setAdapter(adapter);
}

//在Recycler视图上设置数据，但不起作用：（

06-07 17：04：30.190 6255-6255 / com.example.bat.ivolleyrecycler E / Android运行时：致命异常：主要流程：com.example.bat.ivolleyrecycler，PID：6255 java.lang.IllegalStateException：无法执行android：onClick的方法在android.support.v7.app.AppCompatViewInflater $ DeclaredOnClickListener.onClick（AppCompatViewInflater.java:390）在android.view.View.performClick（View.java:4780）在android.view.View $ PerformClick.run（View.java:19866）在android.os.Handler.handleCallback（Handler.java:739）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5293）在java.lang.reflect.Method.invoke（本机方法）在java.lang.reflect.Method.invoke（Method.java:372）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:903）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:698）造成原因：java.lang.reflect.InvocationTargetException 在java.lang.reflect.Method.invoke（本机方法）在java.lang.reflect.Method.invoke（Method.java:372）在android.support.v7.app.AppCompatViewInflater $ DeclaredOnClickListener.onClick（AppCompatViewInflater.java:385）在android.view.View.performClick（View.java:4780）在android.view.View $ PerformClick.run（View.java:19866）在android.os.Handler.handleCallback（Handler.java:739）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5293）在java.lang.reflect.Method.invoke（本机方法）在java.lang.reflect.Method.invoke（Method.java:372）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:903）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:698）原因：java.lang.ClassCastException：无法将java.util.ArrayList强制转换为android.os.Parcelable 在com.example.bat.ivolleyrecycler.MainActivity.GoOnClick（MainActivity.java:55）

//错误

我希望在MainActivity1中单击“打开”按钮时在MainActivity2上的Recycler View上向我显示数据

Answer 1

尝试这样：

ArrayList<MyData> list = new ArrayList<MyData>();
Intent intent = new Intent(MainActivity.this, Main2Activity.class);
Bundle args = new Bundle();
args.putSerializable("myList",(Serializable)list);
intent.putExtra("myKey",args);
startActivity(intent);

将数组列表放入MainActivity.java中，如下所示：

Bundle args = getIntent().getBundleExtra("myKey");
ArrayList<MyData> newList = (ArrayList<MyData>) args.getSerializable("myList");

Answer 2

Gson gson = new Gson;

    //this code to send data via intent

        String json = new Gson().toJson(yourList);

     Intent intent = new Intent(MainActivity.this , Main2Activity.class);
     intent.putExtra("key",json);

        startActivity(intent);


    //this code to get data from intent
    mainList = new ArrayList<>();
 mainList = gson.fromJson(getIntent().getStringExtra("key"), new TypeToken<List<MyData>>() {
        }.getType());

Answer 3

您可以在线在jsonpojo中创建JSON数据的模型，然后重新设计模型类。 http://www.jsonschema2pojo.org/。然后它将起作用。

Intent intent = new Intent(context, Activity.class);
                intent.putExtra("A", ArrayList.);
                context.startActivity(intent);

在下一个活动中

if(getIntent().getParcelableExtra("A") != null){ list = getIntent().getParcelableExtra("A");}

希望有帮助

Answer 4

使用putExtra代替putParcelableArrayList，而使用getParcelableExtra代替getParcelableArrayList。

传递数据：

intent.putExtra(key, list)

获取数据：

list=getIntent().getParcelableExtra(key)

使用ArrayList

4 个答案: