检查packageName对应app是否安装

// 检查packageName对应app是否安装
	public static boolean checkApkExist(Context context, String packageName) {
		if (packageName == null || "".equals(packageName))
			return false;
		try {
			context.getPackageManager().getApplicationInfo(packageName,
					PackageManager.GET_UNINSTALLED_PACKAGES);
			return true;
		} catch (NameNotFoundException e) {
			return false;
		}
	}