两个Activity之间的交互startActivityForResult的使用

代码如下：

package com.zzw.teststartintentforrequest;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class MainActivity extends Activity {

    private final int REQUESTCODE_MAIN = 1;

    private final String KEY_MAIN = "key_main";
    private final String KEY_B = "key_b";

    private TextView textView;

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

        textView = (TextView) findViewById(R.id.textView_main);

        findViewById(R.id.button_main).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, ActivityB.class);
                int a=(int) (Math.random()*100);
                int b=(int) (Math.random()*100);
                int[] nums = { a, b };
                intent.putExtra(KEY_MAIN, nums);
                startActivityForResult(intent, REQUESTCODE_MAIN);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(data!=null){
            Log.d("-------", "requestCode:"+requestCode+"   resultCode:"+resultCode);
            textView.setText(data.getIntExtra(KEY_B, 0)+"");
        }
    }
}

package com.zzw.teststartintentforrequest;

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

public class ActivityB extends Activity {
    
    private final int RESULTCODE_B=2;
    
    private final String KEY_MAIN="key_main";
    private final String KEY_B="key_b";
    
    private TextView textView;
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activityb);
        
        textView=(TextView) findViewById(R.id.textView_B);
        
        int nums[]=this.getIntent().getIntArrayExtra(KEY_MAIN);
        
        final int sum=nums[0]+nums[1];
        
        textView.setText(nums[0]+"+"+nums[1]+"="+sum);
        
        findViewById(R.id.button_B).setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(ActivityB.this,MainActivity.class);
                intent.putExtra(KEY_B,sum);
                ActivityB.this.setResult(RESULTCODE_B, intent);
                ActivityB.this.finish();
            }
        });
    }
    
    
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/holo_blue_light"
    tools:context="com.zzw.teststartintentforrequest.MainActivity" >

    <TextView
        android:id="@+id/textView_main"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="0"
        android:textColor="@android:color/holo_red_light"
        android:textSize="30sp" />

    <Button
        android:id="@+id/button_main"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="38dp"
        android:background="@android:color/holo_blue_light"
        android:text="点击跳转AcyivityB"
        android:textColor="@android:color/holo_red_light" />

</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/black"
    tools:context="com.zzw.teststartintentforrequest.MainActivity" >

    <TextView
        android:id="@+id/textView_B"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textColor="@android:color/white"
        android:textSize="30sp" />

    <Button
        android:id="@+id/button_B"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:background="@android:color/black"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="38dp"
        android:text="点击返回MainAcyivity" />

</RelativeLayout>