在Android中startActivityForResult主要作用就是:

A-Activity需要在B-Activtiy中执行一些数据操作，而B-Activity又要将，执行操作数据的结果返回给A-Activtiy

//看效果

//看代码

package sn.len.actres;

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

public class ActivityResultDemoActivity extends Activity
{
	private Button button_start_task;
	private TextView TextView_result;
	@Override
	public void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		button_start_task=(Button) findViewById(R.id.button_start_task);
		TextView_result=(TextView) findViewById(R.id.TextView_result);
		button_start_task.setOnClickListener(new button_start_task_Listener());
	}
	private class button_start_task_Listener implements OnClickListener
	{
		public void onClick(View v)
		{
			Intent intent=new Intent(ActivityResultDemoActivity.this,SimpleTaskActivity.class);
			//关键点来了，使用startActivityForResult来启动
			startActivityForResult(intent, 100);
		}
	}
	/**
	 * 复写onActivityResult，这个方法
	 * 是要等到SimpleTaskActivity点了提交过后才会执行的
	 */
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data)
	{
		//可以根据多个请求代码来作相应的操作
		if(20==resultCode)
		{
			String bookname=data.getExtras().getString("bookname");
			String booksale=data.getExtras().getString("booksale");
			TextView_result.setText("书籍名称:"+bookname+"书籍价钱"+booksale+"元");
		}
		super.onActivityResult(requestCode, resultCode, data);
	}
}

//任务处理类