初学移动开发技术_两个页面相互跳转，并且向上一个活动传递数据并显示

一、实验内容：

     从MainActivity跳转到SecondActivity，当从SecondActivity向MainActivity跳转时，传递并显示数据

二、代码

  （1）MainActivity

package cn.bzu.tong.tiaozhuan;

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

public class MainActivity extends Activity
{

	private Button btnClick1;
	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		btnClick1=(Button) findViewById(R.id.btnClick1);
		btnClick1.setOnClickListener(new OnClickListener()
		{
			
			public void onClick(View view)
			{
				Intent intent = new Intent(MainActivity.this,SecondActivity.class) ;
	            startActivityForResult(intent,1) ;
			}
		});
		
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data)
	{
		super.onActivityResult(requestCode, resultCode, data);
		switch (resultCode)//判断数据来源
		{
		case 1:
			if(reultCode==RESULT_OK){//看数据是否正常返回
				String returnData = data.getStringExtra("data_return");
				Toast.makeText(this, "returnData="+returnData, Toast.LENGTH_LONG).show();
			  
				Log.d("MainActivity", "returnData="+returnData);
				
			}
			break;

	
		}
		
	}
	
	@Override
	public boolean onCreateOptionsMenu(Menu menu)
	{
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

(2) SecondActivity

package cn.bzu.tong.tiaozhuan;

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

public class SecondActivity extends Activity
{

	private Button btnClick2;
	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_second);
		
		btnClick2=(Button) findViewById(R.id.btnClick2);
		btnClick2.setOnClickListener(new OnClickListener()
		{
			
			@Override
			public void onClick(View view)
			{
				Intent intent=new Intent();
				
				intent.putExtra("data_return","相信自己");
				setResult(RESULT_OK,intent);
				finish();
							}
		});
	}

	
	@Override
	public boolean onCreateOptionsMenu(Menu menu)
	{
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.second, menu);
		return true;
	}

}

三、要实现好向上一活动传递数据并显示，要充分利用好