activity的开启和关闭数据返回

1.打开的activity需要在清单文件中设置：

<activity name ="" icon="">

　　<intent-filter>

　　　　<action name="acfroid.intent.action.MAIN">

　　　　<catogory name="android.intent.catagory.LAUNCHER"/>

　　</intent-filter>

</activity>

2.开启一个activity

（1）开启一个一直的activity

Intent intent = new Intent(this, SignInActivity.class); startActivity(intent);
(2)开启一个短信

Intent intent = new Intent(Intent.ACTION_SEND); intent.putExtra(Intent.EXTRA_EMAIL, recipientArray); startActivity(intent);
3.打开activity的数据返回

private void pickContact() {    
 // Create an intent to "pick" a contact, as defined by the content provider URI    
 Intent intent = new Intent(Intent.ACTION_PICK, Contacts.CONTENT_URI);     
startActivityForResult(intent, PICK_CONTACT_REQUEST); 
}
@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    // If the request went well (OK) and the request was PICK_CONTACT_REQUEST 
    if (resultCode == Activity.RESULT_OK && requestCode == PICK_CONTACT_REQUEST) {  
       // Perform a query to the contact's content provider for the contact's name  
       Cursor cursor = getContentResolver().query(data.getData(),
         new String[] {Contacts.DISPLAY_NAME}, null, null, null);
         if (cursor.moveToFirst()) { 
　　　　　　　　// True if the cursor is not empty 
            int columnIndex = cursor.getColumnIndex(Contacts.DISPLAY_NAME)
            String name = cursor.getString(columnIndex); 
            // Do something with the selected contact's name...         }     } }