findViewById 在不同类的静态方法中 [英] findViewById in static method in different class

问题描述

在我的 android 片段内部，我对我的应用程序是否在平板电脑上运行进行了以下简单检查(在平板电脑上我打开了 3 个视图，在手机上看不到视图 2 和 3，只有第一个一个看到了)

Inside on of my android fragments I have the following simple check as to whether my app runs on a tablet or not (on a tablet I have 3 views open, view 2 and 3 are not seen on a phone, only the first one is seen)

boolean mDualPane;
View detailsFrame = getActivity().findViewById(R.id.content1);
mDualPane = detailsFrame != null && detailsFrame.getVisibility() == View.VISIBLE;

这在片段本身中工作正常，但我需要在许多片段中进行完全相同的检查，因此我希望将它放在我用于多个类中常用方法的MiscMethods"类中.现在我班上同样的鳕鱼看起来像这样:

This works fine in the fragment itself, but I need the exact same check in many fragments and so I wanted to have it in my "MiscMethods" class that I use for frequently used methods in multiple classes. Now the same cod in my class looks like this:

public class MiscMethods{    
public static boolean landscapeChecker(){
    boolean mDualPane;
    View detailsFrame = getActivity().findViewById(R.id.content1);
    mDualPane = detailsFrame != null && detailsFrame.getVisibility() == View.VISIBLE;
    return mDualPane;   
}
}

getActivity(如果我删除了 findViewById)对于 MiscMethods 类型是未定义的.

getActivity (and if I delete that findViewById) is undefined for the type MiscMethods.

现在我有一个像这里这样的上下文的应用程序类

Now I have an Application class for context like here

public static void ErrorToast(int errorCode) {
    String errorString = null;
    switch (errorCode) {
    case 1:
        errorString = App.getContext().getString(R.string.error_tooManyFieldsEmpty);
        break;
    case 2:
        errorString = App.getContext().getString(R.string.error_featureComingSoon);
        break;
    case 3:
        errorString = App.getContext().getString(R.string.error_SwitchBreak);
        break;
    default:
        errorString="Wrong Error Code";
        break;
    }
    Toast errormsg = Toast.makeText(App.getContext(), errorString, Toast.LENGTH_SHORT);
    errormsg.setGravity(Gravity.CENTER, 0, 0);
    errormsg.show();
}

但是这个 App.getContext() 也没有帮助.

but this App.getContext() also does not help.

我该如何解决这个问题?

How can I fix this?

推荐答案

看起来您正在寻找一个快速而肮脏的解决方案，所以这里有两个:

It looks like you're searching for a quick-and-dirty solution, so here are two:

• 更改方法签名以将活动作为参数:

• Change the method signature's to take the activity as a parameter:

public static boolean LandscapeChecker(Activity activity).

在方法中，使用传入的activity 代替getActivity().从您的各种活动中调用它，例如 boolean mDualPane = LandscapeChecker(this).

In the method, use the passed-in activity in place of getActivity(). Call it from your various activities like boolean mDualPane = landscapeChecker(this).

子类 Activity 并将方法放在那里.对于此解决方案，您将创建一个类 MyActivity extends Activity，然后让您的各种活动 extend MyActivity 而不是 extend Activity.在方法中，使用this代替getActivity().

Subclass Activity and put the method there instead. For this solution, you would create a class MyActivity extends Activity, then make your various activities extend MyActivity instead of extend Activity. In the method, use this in place of getActivity().

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