Android中Activity处理返回结果的实现方式

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout
 3     xmlns:android="http://schemas.android.com/apk/res/android"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:id="@+id/activity_main"
 6     android:layout_width="match_parent"
 7     android:layout_height="match_parent"
 8     android:orientation="vertical"
 9     tools:context="com.example.administrator.testactivity.MainActivity">
10     <TextView
11         android:id="@+id/tv1"
12         android:layout_width="match_parent"
13         android:layout_height="wrap_content"
14         android:hint="潘侯爷的属相"
15         android:gravity="center"
16         android:textSize="30sp"/>
17     <Button
18         android:id="@+id/btn1"
19         android:layout_width="wrap_content"
20         android:layout_height="wrap_content"
21         android:layout_gravity="right"
22         android:text="确定"/>
23 </LinearLayout>

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:tools="http://schemas.android.com/tools"
 4     android:id="@+id/activity_main2"
 5     android:layout_width="match_parent"
 6     android:layout_height="match_parent"
 7     tools:context="com.example.administrator.day15.Main2Activity">
 8     <ListView
 9         android:id="@+id/lv"
10         android:layout_width="match_parent"
11         android:layout_height="match_parent"></ListView>
12 </RelativeLayout>

 1 import android.content.Intent;
 2 import android.support.v7.app.AppCompatActivity;
 3 import android.os.Bundle;
 4 import android.view.Gravity;
 5 import android.view.View;
 6 import android.widget.Button;
 7 import android.widget.TextView;
 8 import android.widget.Toast;
 9 public class MainActivity extends AppCompatActivity {
10     private Button btn1;
11     private TextView tv1;
12     @Override
13     protected void onCreate(Bundle savedInstanceState) {
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.activity_main);
16         btn1 = (Button) findViewById(R.id.btn1);
17         tv1 = (TextView) findViewById(R.id.tv1);
18         tv1.setClickable(true);
19         tv1.setOnClickListener(new View.OnClickListener() {
20             @Override
21             public void onClick(View v) {
22                 Intent intent = new Intent(MainActivity.this, Main2Activity.class);
23                 //设置启动intent以及对应的请求码
24                 startActivityForResult(intent, 2);
25             }
26         });
27         btn1.setOnClickListener(new View.OnClickListener() {
28             @Override
29             public void onClick(View v) {
30               Toast t=  Toast.makeText(MainActivity.this, tv1.getText().toString(), Toast.LENGTH_SHORT);
31                 t.setGravity(Gravity.TOP,0,0);
32                 t.show();
33             }
34         });
35     }
36     @Override
37     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
38         super.onActivityResult(requestCode, resultCode, data);
39         //建议添加逻辑判断（使请求码与结果码配对，确保返回结果是请求码所请求的）
40         tv1.setText(data.getStringExtra("select"));
41     }
42 }

 1 import android.content.Intent;
 2 import android.support.v7.app.AppCompatActivity;
 3 import android.os.Bundle;
 4 import android.view.View;
 5 import android.widget.AdapterView;
 6 import android.widget.ArrayAdapter;
 7 import android.widget.ListView;
 8 public class Main2Activity extends AppCompatActivity {
 9     private ListView lv;
10     String[] names={"马","牛","虎","兔","龙"};
11     @Override
12     protected void onCreate(Bundle savedInstanceState) {
13         super.onCreate(savedInstanceState);
14         setContentView(R.layout.activity_main2);
15         lv = (ListView) findViewById(R.id.lv);
16         //使用ArrayAdapter为ListView每个单元格填充数据
17         ArrayAdapter<String> adapter = new ArrayAdapter<String>(Main2Activity.
18                 this,android.R.layout.simple_list_item_single_choice,names);
19         //设置ListView为单选模式
20         lv.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
21         //为ListView中的每个ITERM设置单击事件
22         lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
23             @Override
24             public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
25                 Intent intent =new Intent(Main2Activity.this, MainActivity.class);;
26                 //将选中的item对应的信息配上键值装入Extra中供传递用
27                 intent.putExtra("select",names[position]);
28                 //设置3为结果码
29                 setResult(3,intent);
30                 finish();//结束当前Activity，返回上一个activity
31             }
32         });
33         lv.setAdapter(adapter);
34     }
35 }