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
代码语言：javascript复制<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
代码语言：javascript复制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();
}
}
} 以上就是本文的全部内容，希望对大家的学习有所帮助。
