Android--activity獲取返回值淺析

寫了一個DEMO：短信選擇聯系人的數據傳遞

主activity：

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

public class MainActivity extends Activity {

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

	public void click(View c){
		//跳轉至選擇聯系人Activity
		Intent intent = new Intent(this, ContactActivity.class);
//		startActivity(intent);
		//用這個api啟動的Activity，在銷毀時，系統會回調onActivityResult
		startActivityForResult(intent, 10);
	}
	
	
	public void click2(View v){
		//跳轉至選擇快捷回復的Activity
		Intent intent = new Intent(this, CallbackActivity.class);
		startActivityForResult(intent, 20);
	}
	//如果有Activity在銷毀時返回了數據，那麼就會調用此方法來接收數據
	//requestCode:用來區分數據來自於哪一個Activity
	//resultCode:用來區分返回的數據是什麼類型的
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		// TODO Auto-generated method stub
		super.onActivityResult(requestCode, resultCode, data);
		
		String name = data.getStringExtra("name");
		if(requestCode == 10){
			EditText et = (EditText)findViewById(R.id.et);
			et.setText(name);
		}
		else if(requestCode == 20){
			EditText et_content = (EditText)findViewById(R.id.et_content);
			et_content.setText(name);
		}
	}
	

}

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class ContactActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_contact);
		
		ListView lv = (ListView) findViewById(R.id.lv);
		
		final String[] objects = new String[]{
				"小志",
				"逼哥",
				"世界級XXX",
				"國服第一"
		};
		
		lv.setAdapter(new ArrayAdapter(this, R.layout.item_listview, R.id.tv, objects));
	
		//給listview設置條目的點擊偵聽
		lv.setOnItemClickListener(new OnItemClickListener() {

			//當某個條目被點擊時，此方法調用
			@Override
			public void onItemClick(AdapterView parent, View view,
					int position, long id) {
				
				//Activity返回時傳遞數據，也是通過意圖對象
				Intent data = new Intent();
				//把要傳遞的數據封裝至意圖對象中
				data.putExtra("name", objects[position]);
				
				//當前Activity銷毀時，data這個意圖就會傳遞給啟動當前Activity的那個Activity
				setResult(1, data);
				
				//銷毀當前Activity
				finish();
			}
		});
	}
	
	@Override
	public void onBackPressed() {
		// TODO Auto-generated method stub
		super.onBackPressed();
	}
}

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class CallbackActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_contact);
		
		ListView lv = (ListView) findViewById(R.id.lv);
		
		final String[] objects = new String[]{
				"免談，沒戲，滾犢子",
				"媳婦我錯了，求原諒",
				"老子才是一家之主"
		};
		lv.setAdapter(new ArrayAdapter(this, R.layout.item_listview, R.id.tv, objects));
		
		lv.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView parent, View view,
					int position, long id) {
				Intent data = new Intent();
				data.putExtra("name", objects[position]);
				
				setResult(2, data);
				finish();
				
			}
		});
	}
}