由网友(被狗追过的夏天)分享简介：我试图用下面的code获得屏幕宽度和高度的Andr​​oid应用程序开发：I tried to use following code to get screen width and height in android app development:Display display = getWindowManage...

我试图用下面的code获得屏幕宽度和高度的Andr​​oid应用程序开发：

I tried to use following code to get screen width and height in android app development:

Display display = getWindowManager().getDefaultDisplay(); 
int screenWidth = display.getWidth();
int screenHeight = display.getHeight();

但我得到的 NullPointerException异常我显示，为什么呢？如何让屏幕宽度和高度呢？

but I got NullPointerException for my display, why? how to get screen width and height then?

推荐答案

如果你调用一个活动的这个之外，你需要传递的情况下（或者通过一些其他的调用得到它）。然后用它来让你的显示器的指标：

If you're calling this outside of an Activity, you'll need to pass the context in (or get it through some other call). Then use that to get your display metrics:

DisplayMetrics metrics = context.getResources().getDisplayMetrics();
int width = metrics.widthPixels;
int height = metrics.heightPixels;

更新：通过API级别17+，你可以使用getRealSize:

Point displaySize = new Point();
activity.getWindowManager().getDefaultDisplay().getRealSize(displaySize);

如果你想在可用的窗口大小，你可以使用getDecorView从实际显示尺寸减去装修视图大小来计算可用面积：

If you want the available window size, you can use getDecorView to calculate the available area by subtracting the decor view size from the real display size:

Point displaySize = new Point();
activity.getWindowManager().getDefaultDisplay().getRealSize(displaySize);

Rect windowSize = new Rect();
ctivity.getWindow().getDecorView().getWindowVisibleDisplayFrame(windowSize);

int width = displaySize.x - Math.abs(windowSize.width());
int height = displaySize.y - Math.abs(windowSize.height());
return new Point(width, height);

getRealMetrics也可以工作（需要API级别17+），但我还没有尝试过：

getRealMetrics may also work (requires API level 17+), but I haven't tried it yet:

DisplayMetrics metrics = new DisplayMetrics();
activity.GetWindowManager().getDefaultDisplay().getRealMetrics(metrics);