Android判斷apk是否存在

Android判斷某個apk是否存在：

public  boolean isPkgInstalled(Context context, String packageName) {

        if (packageName == null || "".equals(packageName))

            return false;

        android.content.pm.ApplicationInfo info = null;

        try {

            info = context.getPackageManager().getApplicationInfo(packageName, 0);

            return info != null;

        } catch (NameNotFoundException e) {

            return false;

        }

packageName：apk的 包名