首先要知道你要打开apk文件的包名。

可以使用包名查看器查看。百度搜索:android包名查看器

得到包名然后调用以下方法,把包名传入进去就行了。。。

代码:

public void invokingApk(String packageName){
    //实例化PackageManager
    PackageManager packageManager = this.getPackageManager();
    Intent localIntent = new Intent("android.intent.action.MAIN", null);
    localIntent.addCategory("android.intent.category.LAUNCHER");
    Iterator<ResolveInfo> it1 = packageManager.queryIntentActivities(localIntent, 0).iterator();
    //遍历包名
    while (it1.hasNext()) {
        ResolveInfo resolveInfo = it1.next();
        //如果相等,就执行以下程序
        if (!packageName.equals(resolveInfo.activityInfo.applicationInfo.packageName))
            continue;
        ComponentName componentName = new ComponentName(resolveInfo.activityInfo.applicationInfo.packageName,
                resolveInfo.activityInfo.name);
        localIntent.setComponent(componentName);
        //localIntent.addFlags(268435456);
        this.startActivity(localIntent);//跳转到apk
    }
}