ex4_1_subactivity

//AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.ml.ex_4_1">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".SubActivity1">

        </activity>
        <activity android:name=".SubActivity2">

        </activity>
    </application>

</manifest>

//MainActivity.java

package com.example.ml.ex_4_1;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    private static final int SUBACTIVITY1 = 1;
    private static final int SUBACTIVITY2 = 2;

    TextView textView;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (TextView)findViewById(R.id.textShow);
        final Button btn1 = (Button)findViewById(R.id.btn1);
        final Button btn2 = (Button)findViewById(R.id.btn2);

        btn1.setOnClickListener(new OnClickListener(){
            public void onClick(View view){
                Intent intent = new Intent(MainActivity.this, SubActivity1.class);
                startActivityForResult(intent, SUBACTIVITY1);
            }
        });

        btn2.setOnClickListener(new OnClickListener(){
            public void onClick(View view){
                Intent intent = new Intent(MainActivity.this, SubActivity2.class);
                startActivityForResult(intent, SUBACTIVITY2);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch(requestCode){
            case SUBACTIVITY1:
            v    if (resultCode == RESULT_OK){
                    Uri uriData = data.getData();
                    textView.setText(uriData.toString());
                }
                break;
            case SUBACTIVITY2:
                break;
        }
    }
}

//SubActivity1.java

package com.example.ml.ex_4_1;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class SubActivity1 extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.subactivity1);
        
        final EditText editText = (EditText)findViewById(R.id.edit);
        Button btnOK = (Button)findViewById(R.id.btn_ok);
        Button btnCancel = (Button)findViewById(R.id.btn_cancel);
        
        btnOK.setOnClickListener(new OnClickListener(){
           public void onClick(View view){
              String uriString = editText.getText().toString();
              Uri data = Uri.parse(uriString);
              
              Intent result = new Intent(null, data);
              
              setResult(RESULT_OK, result);
              finish();
           }
        });
        
        btnCancel.setOnClickListener(new OnClickListener(){
           public void onClick(View view){
              setResult(RESULT_CANCELED, null);
              finish();
           }
        });
    }
}

//SubActivity2.java

package com.example.ml.ex_4_1;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class SubActivity2 extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.subactivity2);
        
        Button btnReturn = (Button)findViewById(R.id.btn_return);
        
        btnReturn.setOnClickListener(new OnClickListener(){
           public void onClick(View view){
              setResult(RESULT_CANCELED, null);
              finish();
           }
        });
    }
}

//activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
   android:id="@+id/textShow"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text=""
    />
<Button
   android:id="@+id/btn1"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="启动Activity1"
   />
<Button
   android:id="@+id/btn2"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="启动Activity2"
   />
</LinearLayout>

//subactivity1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
   android:id="@+id/textShow"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="SubActivity 1"
    />
<EditText
   android:id="@+id/edit"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text=""
   />
<Button
   android:id="@+id/btn_ok"
   android:layout_width="100dip"
   android:layout_height="wrap_content"
   android:text="接受"
   />
<Button
   android:id="@+id/btn_cancel"
   android:layout_width="100dip"
   android:layout_height="wrap_content"
   android:text="撤销"
   />
   />
</LinearLayout>

//subactivity2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
   android:id="@+id/textShow"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="SubActivity 2"
    />
<Button
   android:id="@+id/btn_return"
   android:layout_width="100dip"
   android:layout_height="wrap_content"
   android:text="关闭"
   />
</LinearLayout>