Android开发：向下一个activity传递数据，返回数据给上一个activity

 1         Button button=(Button) findViewById(R.id.button1);
 2         button.setOnClickListener(new OnClickListener() {
 3             
 4             @Override
 5             public void onClick(View v) {
 6                 Intent intent=new Intent("1111111111111111111");
 7                 intent.addCategory("android.intent.category.MY_CATEGORY");
 8                 intent.putExtra("aaa", "this is a message");
 9                 startActivityForResult(intent, 0x11);
10             }
11         });

1         Intent intent=getIntent();
2         String data=intent.getStringExtra("aaa");
3         Toast.makeText(activity2.this, data, Toast.LENGTH_SHORT).show();

 1         Button jumpButton=(Button) findViewById(R.id.jumpButton);
 2         jumpButton.setOnClickListener(new OnClickListener() {
 3             @Override
 4             public void onClick(View v) {
 5                 Intent intent=new Intent();
 6                 intent.putExtra("xxx", "This is second activity data!");
 7                 setResult(RESULT_OK,intent);
 8                 finish();
 9             }
10         });

 1     @Override
 2     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 4         super.onActivityResult(requestCode, resultCode, data);
 5           if (requestCode==0x11) {
 6             if (resultCode==RESULT_OK) {
 7                  returnData=data.getStringExtra("xxx");
 8             }
 9         }  
10     }