ListView适配器setResult()和Finish()错误

Question

我想startActivity为结果使用startActivityForResult()方法。现在开始的活动有一个带有适配器类的listview。我已经写了以下Listview适配器，所以当用户选择任何项目，它应该返回到调用活动与选定的项目名称。我不能调用两个方法

setResult() and finish() in following code

适配器代码:

view.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View arg0) {
            SharedPreferences prefernces = mContext.getSharedPreferences("MyKey111", Context.MODE_PRIVATE);
            SharedPreferences.Editor editor1 = prefernces.edit();
            editor1.putString("Custname",customerpopulationlist.get(position).getName());
            editor1.putString("let_id", customerpopulationlist.get(position).getLetId());
            editor1.commit();
            Intent intentMessage = new Intent();
            // put the message in Intent
            intentMessage.putExtra("MESSAGE", "hello");
            intentMessage.putExtra("selected_refer", customerpopulationlist.get(position).getLetId());
            setResult(RESULT_OK, intentMessage);
            finish();
        }
    });

Answer 1

您必须持有一个对创建适配器的活动的引用，然后将结果设置为该活动。你正在做的事情是设置OnClickListener对象的结果!!

将Activity对象添加到适配器构造函数中，并将其保存在适配器的局部变量中，然后调用act，然后调用setResult()活动，如下所示:

view.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View arg0) {
        SharedPreferences prefernces = mContext.getSharedPreferences("MyKey111", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor1 = prefernces.edit();
        editor1.putString("Custname",customerpopulationlist.get(position).getName());
        editor1.putString("let_id", customerpopulationlist.get(position).getLetId());
        editor1.commit();
        Intent intentMessage = new Intent();
        // put the message in Intent
        intentMessage.putExtra("MESSAGE", "hello");
        intentMessage.putExtra("selected_refer", customerpopulationlist.get(position).getLetId());
        //THESE TWO LINES NEED TO BE CHANGED
        act.setResult(RESULT_OK, intentMessage);
        act.finish();
    }
});

Answer 2

您需要在您需要返回的活动上使用override方法protected void onActivityResult(int requestCode, int resultCode, intent data，即您调用startActivityforResult()的活动。

  @override
    protected void onActivityResult(int requestCode, int resultCode, intent data){
    if(resultCode == -1) // -1 for RESULT_OK
    { // your logic goes here...
    }
    }

Answer 3

活动对象和上下文对象之间是有区别的(如果有混淆，最好阅读文档以便更好地理解)所以，答案很简单，

当你想做一个基于活动的操作时，像这样执行

Activity activity = this; 
Context context = ActivityName.this;

传递适配器中的两个对象，然后使用

activity.setResult(Activity.RESULT_OK,intent); 
activity.finish();

对于基于上下文的操作，使用Intent i = new Intent(ListViewAdapter.this.mContext,EventPrivacyAndTicketPrice.class);

见下面的完整活动代码:

    public class ActivityX extends AppCompatActivity {
Intent intent;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_x);
        intent = getIntent();
        ListView listView = findViewById(R.id.list_x);
        ArrayList<ETypeObject> allTypes= new ArrayList<>();
        allTypes = GetData();
        ListViewAdapter listViewAdapter= new       ListViewAdapter(allTypes,ActivityX.this,intent,this);
        listView.setAdapter(listViewAdapter);
    }
    public ArrayList<ETypeObject> GetData(){
        ArrayList<ETypeObject> allTypes= new ArrayList<>();
        allTypes.add(new ETypeObject("Object1",0));
        allTypes.add(new ETypeObject("Object2, Talk",0));
        allTypes.add(new ETypeObject("Object3",0));
   return allTypes;
    }

}
class ETypeObject {
   public String name;
    public int imageId;
    public ETypeObject(String name, int imageId) {
        this.name = name;
        this.imageId = imageId;
    }
    public ETypeObject() {
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getImageId() {
        return imageId;
    }
    public void setImageId(int imageId) {
        this.imageId = imageId;
    }
}


 class ListViewAdapter extends BaseAdapter{
    Activity activity;
    Context mContext;
    ArrayList<ETypeObject> allTypes= new ArrayList<>();
    Intent intent;
    public ListViewAdapter(){}
    public ListViewAdapter(ArrayList<ETypeObject> AllTypes, Context context,Intent intent,Activity activity){
        mContext = context;
        allTypes = AllTypes;
        activity =activity;
        this.intent = intent;
    }

    @Override
    public int getCount() {
        return allTypes.size();
    }
    @Override
    public Object getItem(int i) {
        return allTypes.get(i);
    }
    @Override
    public long getItemId(int i) {
        return i;
    }
    @Override
    public View getView(int i1, View view, ViewGroup viewGroup) {
        LayoutInflater layoutInflater= (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (layoutInflater!=null){
            view = layoutInflater.inflate(R.layout.lay1,null);
        }
        TextView type;

        type = view.findViewById(R.id.parentInteresttext);
        type.setText(allTypes.get(i1).getName());
        view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               // Toast.makeText(mContext,allTypes.get(i1).getName(),Toast.LENGTH_LONG).show();
                if (intent.getBooleanExtra("fromThirdActivty",false)){
                    Intent i = new Intent();
                    i.putExtra("eventType",allTypes.get(i1).getName());
                    activity.setResult(Activity.RESULT_OK,intent);
                    activity.finish();
                }

                Intent i = new Intent( ListViewAdapter.this.mContext,OtherActivity.class);
                i.putExtra("eventType",allTypes.get(i1).getName());
                ListViewAdapter.this.mContext.startActivity(i);
            }
        });
        return view;
    }
}