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

科特林

fun getScreenHeight(activity: Activity): Int {
    val metrics = DisplayMetrics()
    activity.windowManager.defaultDisplay.getMetrics(metrics)
    return metrics.heightPixels
}

fun getScreenWidth(activity: Activity): Int {
    val metrics = DisplayMetrics()
    activity.windowManager.defaultDisplay.getMetrics(metrics)
    return metrics.widthPixels
}

其他回答

在“活动”中使用以下代码。

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int height = metrics.heightPixels;
int wwidth = metrics.widthPixels;

我尝试了所有可能的“解决方案”,但都失败了,我注意到Elliott Hughes的“Dalvik Explorer”应用程序在任何Android设备/操作系统版本上都始终显示正确的维度。我最后看了他的开源项目,可以在这里找到:https://code.google.com/p/enh/

以下是所有相关代码:

WindowManager w = activity.getWindowManager();
Display d = w.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
d.getMetrics(metrics);
// since SDK_INT = 1;
widthPixels = metrics.widthPixels;
heightPixels = metrics.heightPixels;
try {
    // used when 17 > SDK_INT >= 14; includes window decorations (statusbar bar/menu bar)
    widthPixels = (Integer) Display.class.getMethod("getRawWidth").invoke(d);
    heightPixels = (Integer) Display.class.getMethod("getRawHeight").invoke(d);
} catch (Exception ignored) {
}
try {
    // used when SDK_INT >= 17; includes window decorations (statusbar bar/menu bar)
    Point realSize = new Point();
    Display.class.getMethod("getRealSize", Point.class).invoke(d, realSize);
    widthPixels = realSize.x;
    heightPixels = realSize.y;
} catch (Exception ignored) {
}

EDIT:略有改进的版本(避免在不受支持的OS版本上触发异常):

WindowManager w = activity.getWindowManager();
Display d = w.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
d.getMetrics(metrics);
// since SDK_INT = 1;
widthPixels = metrics.widthPixels;
heightPixels = metrics.heightPixels;
// includes window decorations (statusbar bar/menu bar)
if (Build.VERSION.SDK_INT >= 14 && Build.VERSION.SDK_INT < 17)
try {
    widthPixels = (Integer) Display.class.getMethod("getRawWidth").invoke(d);
    heightPixels = (Integer) Display.class.getMethod("getRawHeight").invoke(d);
} catch (Exception ignored) {
}
// includes window decorations (statusbar bar/menu bar)
if (Build.VERSION.SDK_INT >= 17)
try {
    Point realSize = new Point();
    Display.class.getMethod("getRealSize", Point.class).invoke(d, realSize);
    widthPixels = realSize.x;
    heightPixels = realSize.y;
} catch (Exception ignored) {
}

创建Kotlin扩展函数以获取屏幕宽度和高度-

fun Context?.screenWidthInPx(): Int {
    if (this == null) return 0
    val dm = DisplayMetrics()
    val wm = this.getSystemService(Context.WINDOW_SERVICE) as WindowManager
    wm.defaultDisplay.getMetrics(dm)
    return dm.widthPixels
}
//comment
fun Context?.screenHeightInPx(): Int {
    if (this == null) return 0
    val dm = DisplayMetrics()
    val wm = this.getSystemService(Context.WINDOW_SERVICE) as WindowManager
    wm.defaultDisplay.getMetrics(dm)
    return dm.heightPixels
}

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)。

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。