提到过活动的工具类的android [英] Passing reference to activity to utility class android

问题描述

我知道这个问题已经被问了很多次，但我仍然无法完全理解这个概念。在我的应用程序，我使用的是静态的工具类，以保持通用的方法（如显示错误对话框）

I realise this question has been asked many times, but I am still unable to completely understand this concept. In my application, I am using a static utility class to keep common methods (like showing error dialogs)

下面是我的静态类是这样的：

Here is how my static class looks like:

    public class GlobalMethods {

//To show error messages
        public static final void showSimpleAlertDialog(final Activity activity, String  message, final boolean shouldFinishActivity) {

            if (!activity.isFinishing()) {

                AlertDialog.Builder builder = new AlertDialog.Builder(activity, AlertDialog.THEME_HOLO_DARK);
                builder.setCancelable(true).setMessage("\n" + message + "\n").setNeutralButton(activity.getResources().getString(R.string.label_ok), new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        dialog.cancel();

                    }
                }).setOnCancelListener(new DialogInterface.OnCancelListener() {

                    @Override
                    public void onCancel(DialogInterface dialog) {
                        // TODO Auto-generated method stub
                        if (shouldFinishActivity)
                            activity.finish();
                    }
                }).show();
            }

        }

//check for connectivity
    public static final boolean isOnline(Context context) {
        NetworkInfo networkInfo = ((ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
        return (networkInfo != null && networkInfo.isConnectedOrConnecting());
    }

//for the 'HOME' button on every activity
    public static final void goToDashboard(Activity activity) {
        goToActivity(ActivityDashboard.class, activity);

    }

    }

在我的主要活动中，我这样调用这个函数

In my main activity, I call this function like this

GlobalMethods.showSimpleAlertDialog(this, R.string.error_msg_failed_load, true);

这是一个好方法？这是否导致内存泄漏？如果是，请指导我的最佳实践使用的工具类

Is this a good approach? Does this cause memory leaks? If yes, please guide me on the best practices on using utility classes

推荐答案

没有，这是一个不错的办法。 你最好通的WeakReference＆LT;活动＆GT; 来你的方法，并实现这样的方法：

No, it's a bad approach. You better pass WeakReference<Activity> to your methods, and implement methods like this:

public static final void showSimpleAlertDialog(final WeakReference<Activity> mReference, String  message, final boolean shouldFinishActivity) {
    Activity activity = mReference.get();
    if (activity != null) {
        //your code goes here
    }

延伸阅读： HTTP：//android-developers.blogspot .AE / 2009/01 /避免内存，leaks.html

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