我创建了一些自定义元素,并希望以编程方式将它们放置在右上角(距离上边缘n个像素,距离右边缘m个像素)。因此,我需要获得屏幕宽度和屏幕高度,然后设置位置:

int px = screenWidth - m;
int py = screenHeight - n;

如何在主活动中获取screenWidth和screenHeight?


当前回答

创建一个类和方法,如下所示:

public MyPoint getScreenDimensionsAsPixel(Context context){
        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = windowManager.getDefaultDisplay();

        Point point = new Point();
        display.getSize(point);

        return new MyPoint(point.x, point.y);
    }

    public class MyPoint{
        private int width;
        private int height;

        public MyPoint(int width, int height) {
            this.width = width;
            this.height = height;
        }

        public int getWidth() {
            return width;
        }

        public void setWidth(int width) {
            this.width = width;
        }

        public int getHeight() {
            return height;
        }

        public void setHeight(int height) {
            this.height = height;
        }
    }

然后在代码中使用它们:

MyPoint myPoint = getScreenDimensionsAsPixel(MainActivity.this);
                Toast.makeText(MainActivity.this, "width: " + String.valueOf(myPoint.getWidth()) + "|" +
                        "height: " + String.valueOf(myPoint.getHeight()), Toast.LENGTH_LONG).show();

其他回答

此函数以英寸为单位返回近似屏幕大小。

public double getScreenSize()
{
        DisplayMetrics dm = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(dm);
        int width=dm.widthPixels;
        int height=dm.heightPixels;
        int dens=dm.densityDpi;
        double wi=(double)width/(double)dens;
        double hi=(double)height/(double)dens;
        double x = Math.pow(wi,2);
        double y = Math.pow(hi,2);
        double screenInches = Math.sqrt(x+y);
        return screenInches;
}

这是我用于任务的代码:

// `activity` is an instance of Activity class.
Display display = activity.getWindowManager().getDefaultDisplay();
Point screen = new Point();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
    display.getSize(screen);
} else {            
    screen.x = display.getWidth();
    screen.y = display.getHeight();
}

看起来很干净,但要注意贬低。

以下是低于/高于API 30代码的Kotlin扩展函数:

fun Activity.getScreenWidth(): Int {
    return if (Build.VERSION.SDK_INT < 30) {
        val displayMetrics = DisplayMetrics()
        windowManager.defaultDisplay.getMetrics(displayMetrics)
        displayMetrics.widthPixels
    } else {
        val metrics = windowManager.currentWindowMetrics
        val insets = metrics.windowInsets
            .getInsetsIgnoringVisibility(WindowInsets.Type.systemBars())
        metrics.bounds.width() - insets.left - insets.right
    }
}

fun Activity.getScreenHeight(): Int {
    return if (Build.VERSION.SDK_INT < 30) {
        val displayMetrics = DisplayMetrics()
        windowManager.defaultDisplay.getMetrics(displayMetrics)
        displayMetrics.heightPixels
    } else {
        val metrics = windowManager.currentWindowMetrics
        val insets = metrics.windowInsets
            .getInsetsIgnoringVisibility(WindowInsets.Type.systemBars())
        metrics.bounds.height() - insets.top - insets.bottom
    }
}

对应的Java助手方法:

public int getScreenWidth(Activity activity) {
    if (Build.VERSION.SDK_INT < 30) {
        DisplayMetrics displayMetrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        return displayMetrics.widthPixels;
    } else {
        WindowMetrics metrics = activity.getWindowManager().getCurrentWindowMetrics();
        Insets insets = metrics.getWindowInsets()
                .getInsetsIgnoringVisibility(WindowInsets.Type.systemBars());
        return metrics.getBounds().width() - insets.left - insets.right;
    }
}


public int getScreenHeight(Activity activity) {
    if (Build.VERSION.SDK_INT < 30) {
        DisplayMetrics displayMetrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        return displayMetrics.heightPixels;
    } else {
        WindowMetrics metrics = activity.getWindowManager().getCurrentWindowMetrics();
        Insets insets = metrics.getWindowInsets()
                .getInsetsIgnoringVisibility(WindowInsets.Type.systemBars());
        return metrics.getBounds().height() - insets.bottom - insets.top;
    }
}

首先获取视图(例如,通过findViewById()),然后可以对视图本身使用getWidth()。

在Kotlin要简单得多。

val displayMetrics = Resources.getSystem().displayMetrics
displayMetrics.heightPixels
displayMetrics.widthPixels