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

以上代码已在API级别30中弃用。现在您可以使用以下代码

 val width = windowManager.currentWindowMetrics.bounds.width()
 val height = windowManager.currentWindowMetrics.bounds.height()

此方法报告包括所有系统栏区域的窗口大小,而Display#getSize(Point)报告不包括导航栏和显示剪切区域的区域。Display#getSize(Point)报告的值可通过以下方式获得:

 val metrics = windowManager.currentWindowMetrics
 // Gets all excluding insets
 val windowInsets = metrics.windowInsets
 var insets: Insets = windowInsets.getInsets(WindowInsets.Type.navigationBars())
 val cutout = windowInsets.displayCutout
 if (cutout != null) {
    val cutoutSafeInsets = Insets.of(cutout.safeInsetLeft, cutout.safeInsetTop, cutout.safeInsetRight, cutout.safeInsetBottom)
    insets = Insets.max(insets, cutoutSafeInsets)
 }

 val insetsWidth = insets.right + insets.left
 val insetsHeight = insets.top + insets.bottom

 // Legacy size that Display#getSize reports
 val legacySize =  Size(metrics.bounds.width() - insetsWidth, metrics.bounds.height() - insetsHeight)

来源:WindowManager#getCurrentWindowMetrics()

其他回答

需要说明的是,如果您不在“活动”中,而是在“视图”中(或在范围中具有视图类型的变量),则不需要使用WINDOW_SERVICE。那么你至少可以使用两种方法。

第一:

DisplayMetrics dm = yourView.getContext().getResources().getDisplayMetrics();

第二:

DisplayMetrics dm = new DisplayMetrics();
yourView.getDisplay().getMetrics(dm);

我们在这里调用的所有这些方法都没有被弃用。

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;

这里是Kotlin实现中对上面一些答案的简单改编。它需要清单中如上所述的windowsSoftInput=“adjustResize”:

class KeyboardWatcher(private val layoutRooView: View) {

    companion object {
        private const val MIN_KEYBOARD_HEIGHT = 200f
    }

    private val displayMetrics: DisplayMetrics = layoutRooView.resources.displayMetrics
    private var stateVisible = false

    var observer: ((Boolean) -> Unit)? = null

    init {
        layoutRooView.viewTreeObserver.addOnGlobalLayoutListener {
            val heightDiff = layoutRooView.rootView.height - layoutRooView.height
            if (!stateVisible && heightDiff > dpToPx(MIN_KEYBOARD_HEIGHT)) {
                stateVisible = true
                observer?.invoke(stateVisible)
            } else if(stateVisible) {
                stateVisible = false
                observer?.invoke(stateVisible)
            }
        }
    }

    private fun dpToPx(valueInDp: Float): Float {
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, valueInDp, displayMetrics)
    }
}

并使用:

val activityRootView = findViewById<ViewGroup>(R.id.activityRoot)
KeyboardWatcher(activityRootView).observer = { visible ->
    if (visible) do something here ...
}

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)。

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;
    }
}