Android开发获取系统中已安装程序信息的方法

public class AppInfoParser {
  private static String tag = "AppInfoParser";
  public static List getAppInfos(Context context){
   //首先获取到包的管理者
    PackageManager packageManager = context.getPackageManager();
    //获取到所有的安装包
    List installedPackages = packageManager.getInstalledPackages(0);
    ArrayList appInfos = new ArrayList<>();
    for (PackageInfo installedPackage : installedPackages) {
      AppInfo appInfo = new AppInfo();
      //程序包名
      String packageName = installedPackage.packageName;
      appInfo.setPackageName(packageName);
      //获取到图标
      Drawable icon = installedPackage.applicationInfo.loadIcon(packageManager);
      appInfo.setIcon(icon);
      //获取到应用的名字
      String appName = installedPackage.applicationInfo.loadLabel(packageManager).toString();
      appInfo.setAppName(appName);
      //获取到安装包的路径
      String sourceDir = installedPackage.applicationInfo.sourceDir;
      File file = new File(sourceDir);
      //获取到安装apk的大小
      long apkSize = file.length();
      //格式化apk的大小
      appInfo.setApkSize(Formatter.formatFileSize(context,apkSize));
      int flags = installedPackage.applicationInfo.flags;
      //判断当前是否是系统app
      if((flags & ApplicationInfo.FLAG_SYSTEM) !=0){
        //那么就是系统app
        appInfo.setUserApp(false);
      }else{
        //那么就是用户app
        appInfo.setUserApp(true);
      }
      if((flags & ApplicationInfo.FLAG_EXTERNAL_STORAGE)!=0){
       //那么当前安装的就是sd卡
        appInfo.setSD(true);
      }else{
        //那么就是手机内存
        appInfo.setSD(false);
      }
      appInfos.add(appInfo);
    }
    return appInfos;
  }
}

public class AppInfo {
  //应用图标
  private Drawable icon;
  //应用的名字
  private String appName;
  //应用程序的大小
  private String apkSize;
  //表示用户程序
  private boolean isUserApp;
  //存储的位置.
  private boolean isSD;
  private String packageName;
  public String getPackageName() {
    return packageName;
  }
  public void setPackageName(String packageName) {
    this.packageName = packageName;
  }
  public Drawable getIcon() {
    return icon;
  }
  public void setIcon(Drawable icon) {
    this.icon = icon;
  }
  public String getAppName() {
    return appName;
  }
  public void setAppName(String appName) {
    this.appName = appName;
  }
  public String getApkSize() {
    return apkSize;
  }
  public void setApkSize(String apkSize) {
    this.apkSize = apkSize;
  }
  public boolean isUserApp() {
    return isUserApp;
  }
  public void setUserApp(boolean isUserApp) {
    this.isUserApp = isUserApp;
  }
  public boolean isSD() {
    return isSD;
  }
  public void setSD(boolean isSD) {
    this.isSD = isSD;
  }
  @Override
  public String toString() {
    return "AppInfo{" +
        "appName='" + appName + '\'' +
        ", apkSize='" + apkSize + '\'' +
        ", isUserApp=" + isUserApp +
        ", isSD=" + isSD +
        '}';
  }
}