startActivity与startActivityForResult中的intent使用

Intent中指定程序要执行的动作（如：view,edit,dial）以及执行到该动作时所需要的资料，最后调用startActivity()。

1、作用

程序跳转、传递数据

Action/Data/Type/Catogory(对执行动作的附加信息进行描述)/Extras(其它附加信息)/Component(对目标组件的描述)

2、3种形式
startActivity()/startActivityForResult()
BroadcastReceiver
startService(Intent)和bindService(Intent,ServiceConnection,int)

3、相关方法

intent.putExtra(name,value);
intent.putExtras(bundle);
intent.getExtra();
getIntent();

4、常用action

Intent.ACTION_DIAL
Intent.ACTION_CALL
Intent.ACTION_VIEW
Intent.ACTION_EDIT
Intent.ACTION_DELETE
Intent.ACTION_PICK(选择数据)

//这是一个MainActivity，会分别发送startActivity和startActivityForResult
package com.browan.server;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
 protected static final int REQUST_CODE = 0;
 /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);//相关布局模板文件main.xml
        find_and_modif_button();    
        
        
        //startActivityForResult示例
        Button.OnClickListener listener1 = new Button.OnClickListener()
        {
         public void onClick(View v)
         {
          Intent intent1 =  new Intent(MainActivity.this,Activity1.class);
          intent1.putExtra("MainActivity", "这是来自MainActivity的数据。");
          startActivityForResult(intent1,REQUST_CODE);
         }
        };
            //startActivity示例
        Button.OnClickListener listener2 = new Button.OnClickListener()
        {
         public void onClick(View v)
         {
          setTitle("这是在MainActivity");
          Intent intent2 = new Intent(MainActivity.this,Activity2.class);
          startActivity(intent2);
         }
        };
        
        Button button1 = (Button) findViewById(R.id.button1);
        button1.setOnClickListener(listener1);
        
        Button button2 = (Button) findViewById(R.id.button2);
        button2.setOnClickListener(listener2);
        
    }
   //对于返回结果的反映，startActivityForResult返回的结果指令的处理
 protected void onActivityResult(int requst_code,int result_code,Intent data){
     if(requst_code == REQUST_CODE)
     {
      if(result_code == RESULT_CANCELED)
      {
       setTitle("取消");
      }
      else if(result_code == RESULT_OK)
      {
       String temp = "";
       Bundle extras = data.getExtras();
       if(extras != null)
       {
        temp = extras.getString("store");
       }
       setTitle(temp);
      }
      else
      {
       setTitle("Others");
      }
     }
    }
 
}

下面再来看看Activity1.class部分：

package com.browan.server;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class Activity1 extends Activity{
  public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity1);
         
         Button.OnClickListener listener3 = new Button.OnClickListener(){
       public void onClick(View v){     
           Bundle bundle = new Bundle();
           bundle.putString("store", "这是Activity1返回的数据。");
           Intent mIntent = new Intent();
           mIntent.putExtras(bundle);      
           setResult(RESULT_OK,mIntent); //这个就是返回去的消息，setResult在收到消息之后才会被触发返回发送
                                         //MainActivity里面的onActivityResult就会对intent里面的result_code（RESULT_OK）处理

           finish();
       }
      };
      
         Button button3 = (Button) findViewById(R.id.button3);
         button3.setOnClickListener(listener3); 
         
         Bundle extras = getIntent().getExtras();//这里读取到了MainActivity传来的消息内容
         String data = null;
   if(extras != null)
         {
          data  = extras.getString("MainActivity");
         }
         setTitle("现在是在Activity1里：" + data);
  }
}

Activity2.class：

package com.browan.server;
import android.app.Activity;
import android.os.Bundle;
public class Activity2 extends Activity{
  public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity2);
         
         setTitle("这里是在Activity2里。");
  }
}

xml各个的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >    
<Button android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="启动Activity1" />
<Button android:id="@+id/button2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="启动Activity2" />  
</LinearLayout>
5.5 activity1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
  
  <Button android:id="@+id/button3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="点击此按钮返回到MainActivity" />  
</LinearLayout>
5.6 activity2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
</LinearLayout>

 AndroidManifest. xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.browan.server"
      android:versionCode="1"
      android:versionName="1.0">
 <uses-permission android:name="android.permission.NEW_BROADCAST1" /> 
 <uses-permission android:name="android.permission.NEW_BROADCAST2" />  
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
                
        <activity android:name="Activity1">
        </activity>
        <activity android:name="Activity2">
        </activity>
        
    </application>
</manifest>