Android 如何在App中启动系统闹钟

由于不同Android手机厂商提供的系统闹钟包名都不一致，所以只能通过过滤当前手机所有的应用，以确定闹钟应用的包名，进而启动它。

这里采用的过滤规则是：系统应用 && 应用的PackageName包含"widget" 和 "clock"

1>布局文件  activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/start_system_clock_bt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="启动系统闹钟" />

</RelativeLayout>

2>MainActivity.java

package com.demo.cxc.systemclocksample;

import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private Button startSystemClockButton = null;


    private List<PackageInfo> allPackageInfos;//系统安装所有软件
    private List<PackageInfo> clockPackageInfos;//系统时钟软件

    private static final int HANDLE_MESSAGE_KEY = 1001;
    private Handler myHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            if (msg != null) {
                switch (msg.what) {
                    case HANDLE_MESSAGE_KEY:
                        Toast.makeText(getApplicationContext(), "--app scan over--", Toast.LENGTH_SHORT).show();
                        Log.d("CXC", "--app scan over--");
                        break;

                    default:
                        break;

                }

            }

        }
    };

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

        //begin scan installed applications;
        //// TODO: 16/1/15
        new Thread(new ScanInstalledAppsRunnable()).start();
    }

    private void initViews() {
        startSystemClockButton = (Button) findViewById(R.id.start_system_clock_bt);
        startSystemClockButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //// TODO: 16/1/15
                startSystemClock();
            }
        });
    }

    private void initData() {
        clockPackageInfos = new ArrayList<PackageInfo>();
    }


    class ScanInstalledAppsRunnable implements Runnable {
        @Override
        public void run() {
            allPackageInfos = getPackageManager()
                    .getInstalledPackages(0);

            if (allPackageInfos == null || allPackageInfos.size() == 0) {
                //// TODO: 16/1/15 todo nothing
                return;
            }

            if (clockPackageInfos == null) {
                clockPackageInfos = new ArrayList<PackageInfo>();
            }

            PackageInfo tempPackageInfo = null;
            for (int i = 0; i < allPackageInfos.size(); i++) {
                tempPackageInfo = allPackageInfos.get(i);
                if (tempPackageInfo != null) {

                    if (isSystemApplication(tempPackageInfo.applicationInfo) &&
                            isClockApplication(tempPackageInfo.packageName)) {
                        clockPackageInfos.add(tempPackageInfo);
                    }

                }
            }


            Message message = myHandler.obtainMessage();
            message.what = MainActivity.HANDLE_MESSAGE_KEY;
            myHandler.sendMessage(message);
        }
    }


    private boolean isSystemApplication(ApplicationInfo applicationInfo) {
        boolean isSystemApp = false;
        if (applicationInfo != null) {
            if ((applicationInfo.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0
                    || (applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
                isSystemApp = true;

            }
        }
        return isSystemApp;
    }


    private boolean isClockApplication(String packageName) {
        boolean isClockApp = false;
        if (packageName != null && packageName.contains("clock") && !packageName.contains("widget")) {
            isClockApp = true;
        }
        return isClockApp;
    }

    private void startSystemClock() {
        if (clockPackageInfos == null || clockPackageInfos.size() == 0) {
            Toast.makeText(getApplicationContext(), "--启动系统闹钟失败1--", Toast.LENGTH_SHORT).show();
            return;
        }

        Log.d("CXC", "---clock package size :" + clockPackageInfos.size());
        Log.d("CXC", "---clock package [0] :" + clockPackageInfos.get(0).packageName);
        try {
            Intent startSysClockIntent = getPackageManager().getLaunchIntentForPackage(clockPackageInfos.get(0).packageName);
            startActivity(startSysClockIntent);
        } catch (Exception e) {
            Toast.makeText(getApplicationContext(), "--启动系统闹钟失败2--", Toast.LENGTH_SHORT).show();
        }


    }

}