android notification及TaskStackBuilder

　　app开发中，通知栏通知是比较常见的需求，这里有一个体验细节。弹出通知，用户下拉通知栏，点击后进入app中对应页面，看完后想返回上一页，于是点击了左上角或者右上角的返回按钮(一般来说应该都有)，如果用户是从桌面点击通知进入app的，那么app栈内就没有对应的页面，返回上一页就不能通过常规的销毁当前页面来实现，这时就需要使用TaskStackBuilder了.

　　TaskStackBuilder，我的理解就是一个栈构建器，在xml里面给activity1配置一个parentActivityName=activity2,那么通过TaskStackBuilder启动activity1时，系统会先把activity2压入栈，然后再启动activity1，这时如果销毁activity1,activity2就会变为栈顶页面呈现在用户面前。这样就模拟出了历史页面效果，体验要比用户点击返回直接回到桌面要好.

public class NotificationUtil {

    /**
     * 展示通知
     */
    public static void showNotifiation(Context context, String title, String content, int nid, PushReceiverModel pushModel) {
        StaticMethod.debugEMSG("发送通知到通知栏");
        NotificationCompat.Builder mBuilder =
                new NotificationCompat.Builder(context)
                        .setSmallIcon(R.drawable.push)
                        .setContentTitle(title)
                        .setContentText(content);
        TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
        Intent resultIntent;
        if (StaticVariable.rid != null && !StaticVariable.rid.equals("")) {
            if (StaticVariable.rid.equals("3")||StaticVariable.rid.equals("5")) {
                if (pushModel.getMessageType().equals(StaticConstant.系统通知)) {
                    resultIntent = new Intent(context, XSJL_SysytemMsgActivity.class);
                    stackBuilder.addParentStack(XSJL_SysytemMsgActivity.class);
                }else{
                    resultIntent = new Intent(context, XSJL_MsgBoxActivity.class);
                    stackBuilder.addParentStack(XSJL_MsgBoxActivity.class);
                }
            } else if (StaticVariable.rid.equals("6")||StaticVariable.rid.equals("7")) {
                if (pushModel.getMessageType().equals(StaticConstant.微信对话)) {
                    resultIntent = new Intent(context, WeChat_2_Activity.class);
                    resultIntent.putExtra("cid", pushModel.getUid());
                    resultIntent.putExtra("title", pushModel.getName());
                    stackBuilder.addParentStack(WeChat_2_Activity.class);
                } else if (pushModel.getMessageType().equals(StaticConstant.销售新用户)) {
                    resultIntent = new Intent(context, GJXQ_1_Activity.class);
                    if (StaticMethod.isNotNull(pushModel.getUid())) {
                        resultIntent.putExtra("cid", pushModel.getUid());
                    } else {
                        resultIntent.putExtra("cid", pushModel.getAdvid());
                    }
                    stackBuilder.addParentStack(GJXQ_1_Activity.class);
                } else if (pushModel.getMessageType().equals(StaticConstant.系统通知)) {
                    resultIntent = new Intent(context, XSGW_SysytemMsgActivity.class);
                    stackBuilder.addParentStack(XSGW_SysytemMsgActivity.class);
                } else if (pushModel.getMessageType().equals(StaticConstant.抢客户)) {
                    resultIntent = new Intent(context, MainActivity.class);
                } else {
                    resultIntent = new Intent(context, XSGW_TaskNotifyActivity.class);
                    stackBuilder.addParentStack(XSGW_TaskNotifyActivity.class);
                }
            } else {
                resultIntent = new Intent(context, LaunchActivity.class);
            }
        } else {
            resultIntent = new Intent(context, LaunchActivity.class);
        }
        if (stackBuilder.getIntentCount() > 0) {
            stackBuilder.editIntentAt(0).putExtra("aid", StaticVariable.aid);
            stackBuilder.editIntentAt(0).putExtra("uid", StaticVariable.uid);
        }

        stackBuilder.addNextIntent(resultIntent);
        PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT | Intent.FLAG_ACTIVITY_NEW_TASK);

        mBuilder.setContentIntent(resultPendingIntent);
        NotificationManager mNotificationManager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        Notification notification = mBuilder.build();
        notification.flags = Notification.FLAG_AUTO_CANCEL;
        notification.defaults = Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE;
        long[] vibrate = {0, 100, 200, 300};
        notification.vibrate = vibrate;

        mNotificationManager.notify(nid, notification);
    }
}

　　里面有一个比较容易搞混的地方，就是parentActivity。这里用XSJL_SysytemMsgActivity来举例.

　　下面就是XSJL_SystemMsgActivity在AndroidManifest.xml里面的声明

<activity
            android:name=".page.base.xsjl.activity.XSJL_SysytemMsgActivity"
            android:parentActivityName=".page.base.xsjl.activity.MainActivity" />

　　parentActivityName指定的就是当XSJL_SystemMsgActivity被销毁时，需要显示的历史页面.

　　在代码里面这么写

resultIntent = new Intent(context, XSJL_SysytemMsgActivity.class);
//resultIntent.putExtra("cid", pushModel.getUid());给XSJL_SysytemMsgActivity页面传递启动参数
//stackBuilder.editIntentAt(0).putExtra("aid", StaticVariable.aid);给parent页面传递启动参数，
stackBuilder.addParentStack(XSJL_SysytemMsgActivity.class);

　　关键部分就这些，剩下的就是照着官网例子写的。

stackBuilder.addNextIntent(resultIntent);

PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT | Intent.FLAG_ACTIVITY_NEW_TASK);

获取到了PendingIntent，历史页面这一块就结束了，剩下的就是通知部分，没什么难点，抄代码改参数就ok了