Notification中Intent攜帶資料重複問題

Notification中多個Intent使用putExtra方法攜帶資料，在目的activity中通過getIntent方法取出傳遞資料時，有時候會發現取出來的資料都是第一次putExtra中放入的資料。

下面看下代碼，比較簡單：

package com.example.notificationdemo;import android.app.Activity;import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class FirstActivity extends Activity {private Button mButton;private NotificationManager mNotificationManager;private Intent mIntent;private PendingIntent mPendingIntent;Notification mNotification;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.first);mNotification = new Notification();mIntent = new Intent(FirstActivity.this, MainActivity.class);mIntent.putExtra("hello", "first");Log.v("@@@@@@", "this is put in intent first....");mNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);//主要在於PendingIntent的getActivity方法中的參數mPendingIntent = PendingIntent.getActivity(FirstActivity.this, 0, mIntent, PendingIntent.FLAG_UPDATE_CURRENT);//如果使用下面注釋掉的代碼，將會出現上面說講到的問題,當然在SecondActivity中也必須做修改//mPendingIntent = PendingIntent.getActivity(FirstActivity.this, 0, mIntent, 0);mButton = (Button)findViewById(R.id.first_button);mButton.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View view) {showNotification();}});}private void showNotification() {  mNotification.icon = R.drawable.message;mNotification.defaults = Notification.DEFAULT_SOUND; mNotification.flags |= Notification.FLAG_AUTO_CANCEL;mNotification.tickerText = "第一個";mNotification.setLatestEventInfo(FirstActivity.this, "第一個","第一個", mPendingIntent);mNotificationManager.notify(0, mNotification);}}

第二個Activity：

package com.example.notificationdemo;import android.app.Activity;import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class SecondActivity extends Activity {private Button mButton;private NotificationManager mNotificationManager2;private Intent mIntent;private PendingIntent mPendingIntent2;Notification mNotification2;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.second);mNotification2 = new Notification();mIntent = new Intent(SecondActivity.this, MainActivity.class);mIntent.putExtra("hello", "second");Log.v("@@@@@@", "this is doing in second activity");mNotificationManager2 = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);mPendingIntent2 = PendingIntent.getActivity(SecondActivity.this, 1, mIntent, PendingIntent.FLAG_UPDATE_CURRENT);//如果使用下面注釋掉的代碼，將會出現上面說講到的問題,當然在FirstActivity中也必須做修改（把上面代碼注釋掉，使用下面行代碼，就會重現）//mPendingIntent2 = PendingIntent.getActivity(SecondActivity.this, 0, mIntent, 0);mButton = (Button) findViewById(R.id.second_button);mButton.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View view) {showNotification();}});}private void showNotification() {    mNotification2.icon = R.drawable.message2;mNotification2.defaults = Notification.DEFAULT_SOUND; mNotification2.flags |= Notification.FLAG_AUTO_CANCEL;mNotification2.tickerText = "第二個";Log.v("@@@@@@", "intent put second ...");mNotification2.setLatestEventInfo(SecondActivity.this, "第二個", "第二個", mPendingIntent2);Log.v("@@@@@@", "do shownotification in second activity");mNotificationManager2.notify(0, mNotification2);}}

在MainActivity中接受兩個Activity中的Notification傳過來的資料：

package com.example.notificationdemo;import android.os.Bundle;import android.app.TabActivity;import android.content.Intent;import android.graphics.Color;import android.util.Log;import android.view.Menu;import android.widget.RadioButton;import android.widget.RadioGroup;import android.widget.RadioGroup.OnCheckedChangeListener;import android.widget.TabHost;public class MainActivity extends TabActivity implements OnCheckedChangeListener{private TabHost mTabHost;private RadioGroup mRadioGroup;private RadioButton mFirstRadio, mSecondRadio;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                mTabHost = getTabHost();mTabHost.addTab(mTabHost.newTabSpec("first").setIndicator("First").setContent(new Intent(this, FirstActivity.class)));mTabHost.addTab(mTabHost.newTabSpec("second").setIndicator("Second").setContent(new Intent(this, SecondActivity.class)));                mRadioGroup = (RadioGroup) findViewById(R.id.radiogroup);mRadioGroup.setOnCheckedChangeListener(this);mFirstRadio = (RadioButton)findViewById(R.id.first_radio);mSecondRadio = (RadioButton) findViewById(R.id.second_radio);Log.v("@@@@@@", "this is doing  in onCreate");        ChangeChecked(true);        String str = getIntent().getStringExtra("hello");    Log.v("@@@@@@", "the str is " + str);    if (str != null && str.equals("first")) {    ChangeChecked(true);    mTabHost.setCurrentTabByTag("first");    } else if (str != null && str.equals("second")) {    ChangeChecked(false);    mTabHost.setCurrentTabByTag("second");    }            }        @Override    protected void onNewIntent(Intent intent) {        String str = intent.getStringExtra("hello");    if (str != null && str.equals("first")) {    ChangeChecked(true);    mTabHost.setCurrentTabByTag("first");    } else if (str != null && str.equals("second")) {    ChangeChecked(false);    mTabHost.setCurrentTabByTag("second");    }    super.onNewIntent(intent);        }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId) {switch (checkedId) {case R.id.first_radio:mTabHost.setCurrentTabByTag("first");ChangeChecked(true);break;case R.id.second_radio:mTabHost.setCurrentTabByTag("second");ChangeChecked(false);break;default :break;}}private void ChangeChecked(boolean bool) {if (bool) {mFirstRadio.setTextColor(Color.RED);mFirstRadio.setBackgroundResource(R.drawable.tab_front_bg);mSecondRadio.setTextColor(Color.BLACK);mSecondRadio.setBackgroundColor(Color.TRANSPARENT);} else {mSecondRadio.setTextColor(Color.RED);mSecondRadio.setBackgroundResource(R.drawable.tab_front_bg);mFirstRadio.setTextColor(Color.BLACK);mFirstRadio.setBackgroundColor(Color.TRANSPARENT);}}}

問題主要出自：

mPendingIntent2 = PendingIntent.getActivity(SecondActivity.this, 1, mIntent, PendingIntent.FLAG_UPDATE_CURRENT);//如果使用下面注釋掉的代碼，將會出現上面說講到的問題,當然在FirstActivity中也必須做修改（把上面代碼注釋掉，使用下面行代碼，就會重現）//mPendingIntent2 = PendingIntent.getActivity(SecondActivity.this, 0, mIntent, 0);

看一下getActivity方法：

 PendingIntent android.app.PendingIntent.getActivity(Context context, int requestCode, Intent intent, int flags)Retrieve a PendingIntent that will start a new activity, like calling Context.startActivity(Intent). Note that the activity will be started outside of the context of an existing activity, so you must use the Intent.FLAG_ACTIVITY_NEW_TASK launch flag in the Intent.Parameters:context The Context in which this PendingIntent should start the activity.requestCode Private request code for the sender (currently not used).intent Intent of the activity to be launched.flags May be FLAG_ONE_SHOT, FLAG_NO_CREATE, FLAG_CANCEL_CURRENT, FLAG_UPDATE_CURRENT, or any of the flags as supported by Intent.fillIn() to control which unspecified parts of the intent that can be supplied when the actual send happens.Returns:Returns an existing or new PendingIntent matching the given parameters. May return null only if FLAG_NO_CREATE has been supplied.

參數requestCode用於區分Intent，如果flag為FLAG_UPDATE_CURRENT會即使更新intent中資料。

關於該方法的詳細概述，敬請查看後面關於notification的源碼解析，打算在周末的時候看一下notification源碼，那個時候再詳細分析下。