似乎所有这些答案都不适合我的Galaxy M51和Android 11。在做了一些研究之后，我发现了这个代码:

WindowMetrics windowmetrics = MainActivity.getWindowManager().getCurrentWindowMetrics();
Rect rect = windowmetrics.getBounds();
int width = rect.right;
int height =rect.bottom;

显示我的真实设备分辨率为1080x2400，其余只返回810x1800。

使用这段代码，你可以得到运行时显示的宽度和高度:

DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int height = displayMetrics.heightPixels;
int width = displayMetrics.widthPixels;

在视图中，你需要这样做:

((Activity) getContext()).getWindowManager()
                         .getDefaultDisplay()
                         .getMetrics(displayMetrics);

在某些情况下，设备有一个导航栏，你必须在运行时检查:

public boolean showNavigationBar(Resources resources)
{
    int id = resources.getIdentifier("config_showNavigationBar", "bool", "android");
    return id > 0 && resources.getBoolean(id);
}

如果设备有一个导航栏，那么计算它的高度:

private int getNavigationBarHeight() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        int usableHeight = metrics.heightPixels;
        getWindowManager().getDefaultDisplay().getRealMetrics(metrics);
        int realHeight = metrics.heightPixels;
        if (realHeight > usableHeight)
            return realHeight - usableHeight;
        else
            return 0;
    }
    return 0;
}

所以设备的最终高度是:

int height = displayMetrics.heightPixels + getNavigationBarHeight();

对于kotlin用户

fun Activity.displayMetrics(): DisplayMetrics {
   val displayMetrics = DisplayMetrics()
   windowManager.defaultDisplay.getMetrics(displayMetrics)
   return displayMetrics
}

在Activity中，你可以使用它

     resources.displayMetrics.let { displayMetrics ->
        val height = displayMetrics.heightPixels
        val width = displayMetrics.widthPixels
    }

或者碎片化

    activity?.displayMetrics()?.run {
        val height = heightPixels
        val width = widthPixels
    }

DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int height = displayMetrics.heightPixels;
int width = displayMetrics.widthPixels;

在某些情况下，这可能行不通。获取getMetrics注释:

Gets display metrics that describe the size and density of this display. The size returned by this method does not necessarily represent the actual raw size (native resolution) of the display. The returned size may be adjusted to exclude certain system decor elements that are always visible. It may be scaled to provide compatibility with older applications that were originally designed for smaller displays. It can be different depending on the WindowManager to which the display belongs. If requested from non-Activity context (e.g. Application context via (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE)) metrics will report the size of the entire display based on current rotation and with subtracted system decoration areas. If requested from activity (either using getWindowManager() or (WindowManager) getSystemService(Context.WINDOW_SERVICE)) resulting metrics will correspond to current app window metrics. In this case the size can be smaller than physical size in multi-window mode.

所以，要得到真正的大小:

DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getRealMetrics(displayMetrics);
int height = displayMetrics.heightPixels;
int width = displayMetrics.widthPixels;

or:

Point point = new Point();
getWindowManager().getDefaultDisplay().getRealSize(point);
int height = point.y;
int width = point.x;

public class DisplayInfo {
    int screen_height=0, screen_width=0;
    WindowManager wm;
    DisplayMetrics displaymetrics;

    DisplayInfo(Context context) {
        getdisplayheightWidth(context);
    }

    void getdisplayheightWidth(Context context) {
        wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        displaymetrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(displaymetrics);
        screen_height = displaymetrics.heightPixels;
        screen_width = displaymetrics.widthPixels;
    }

    public int getScreen_height() {
        return screen_height;
    }

    public int getScreen_width() {
        return screen_width;
    }
}

在Android中很容易获得:

int width  = Resources.getSystem().getDisplayMetrics().widthPixels;
int height = Resources.getSystem().getDisplayMetrics().heightPixels;