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

我有两个函数,一个用于发送上下文,另一个用于获取像素的高度和宽度:

public static int getWidth(Context mContext){
    int width=0;
    WindowManager wm = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
    Display display = wm.getDefaultDisplay();
    if(Build.VERSION.SDK_INT>12){
        Point size = new Point();
        display.getSize(size);
        width = size.x;
    }
    else{
        width = display.getWidth();  // Deprecated
    }
    return width;
}

and

public static int getHeight(Context mContext){
    int height=0;
    WindowManager wm = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
    Display display = wm.getDefaultDisplay();
    if(Build.VERSION.SDK_INT>12){
        Point size = new Point();
        display.getSize(size);
        height = size.y;
    }
    else{
        height = display.getHeight();  // Deprecated
    }
    return height;
}

有一种使用DisplayMetrics(API 1)来实现这一点的方法并不过时,它可以避免try/catch混乱:

 // initialize the DisplayMetrics object
 DisplayMetrics deviceDisplayMetrics = new DisplayMetrics();

 // populate the DisplayMetrics object with the display characteristics
 getWindowManager().getDefaultDisplay().getMetrics(deviceDisplayMetrics);

 // get the width and height
 screenWidth = deviceDisplayMetrics.widthPixels;
 screenHeight = deviceDisplayMetrics.heightPixels;

如果您不想增加WindowManagers、Points或Displays的开销,可以获取XML中最顶层View项的高度和宽度属性,前提是其高度和宽度设置为match_parent。(只要您的布局占据整个屏幕,这是正确的。)

例如,如果您的XML以以下内容开头:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/entireLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

然后findViewById(R.id.entireLayout).getWidth()将返回屏幕的宽度,findViewById(R.id.entireLayout).getHeight()将显示屏幕的高度。

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;
}

我有一个启动屏幕活动,LinearLayout作为根视图,其宽度和高度为match_parent。这是该活动的onCreate()方法中的代码。我在应用程序的所有其他活动中使用这些度量。

int displayWidth = getRawDisplayWidthPreHoneycomb();
int rawDisplayHeight = getRawDisplayHeightPreHoneycomb();
int usableDisplayHeight = rawDisplayHeight - getStatusBarHeight();
pf.setScreenParameters(displayWidth, usableDisplayHeight);

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
    LinearLayout myView = (LinearLayout) findViewById(R.id.splash_view);
    myView.addOnLayoutChangeListener(new OnLayoutChangeListener() {
        @Override
        public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
            if (left == 0 && top == 0 && right == 0 && bottom == 0) {
                return;
            }
            int displayWidth = Math.min(right, bottom);
            int usableDisplayHeight = Math.max(right, bottom);
            pf.setScreenParameters(displayWidth, usableDisplayHeight);
        }
    });
}

下面是上面调用的方法的实现:

private int getRawDisplayWidthPreHoneycomb() {
    WindowManager windowManager = getWindowManager();
    Display display = windowManager.getDefaultDisplay();
    DisplayMetrics displayMetrics = new DisplayMetrics();
    display.getMetrics(displayMetrics);

    int widthPixels = displayMetrics.widthPixels;
    int heightPixels = displayMetrics.heightPixels;

    return Math.min(widthPixels, heightPixels);
}

private int getRawDisplayHeightPreHoneycomb() {
    WindowManager w = getWindowManager();
    Display d = w.getDefaultDisplay();
    DisplayMetrics metrics = new DisplayMetrics();
    d.getMetrics(metrics);

    int widthPixels = metrics.widthPixels;
    int heightPixels = metrics.heightPixels;

    return Math.max(widthPixels, heightPixels);
}

public int getStatusBarHeight() {
    int statusBarHeight = 0;

    int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
    if (resourceId > 0) {
        statusBarHeight = getResources().getDimensionPixelSize(resourceId);
    }

    return statusBarHeight;
}

这将导致所有API版本和不同类型的设备(手机和平板电脑)的可用显示的高度和宽度,不包括任何类型的栏(状态栏、导航栏)。