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

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 ...
}

其他回答

现在在Api 30级别上,应该这样做

final WindowMetrics metrics = windowManager.getCurrentWindowMetrics();
 // Gets all excluding insets
 final WindowInsets windowInsets = metrics.getWindowInsets();
 Insets insets = windowInsets.getInsetsIgnoreVisibility(WindowInsets.Type.navigationBars()
         | WindowInsets.Type.displayCutout());

 int insetsWidth = insets.right + insets.left;
 int insetsHeight = insets.top + insets.bottom;

 // Legacy size that Display#getSize reports
 final Rect bounds = metrics.getBounds();
 final Size legacySize = new Size(bounds.width() - insetsWidth,
         bounds.height() - insetsHeight);

简单的功能与较低版本兼容。

/**
 * @return screen size int[width, height]
 *
 * */
public int[] getScreenSize(){
    Point size = new Point();
    WindowManager w = getWindowManager();

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2){
        w.getDefaultDisplay().getSize(size);
        return new int[]{size.x, size.y};
    }else{
        Display d = w.getDefaultDisplay();
        //noinspection deprecation
        return new int[]{d.getWidth(), d.getHeight()};
    }
}

要使用:

int width = getScreenSize()[0];
int height = getScreenSize()[1];

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

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;
}

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。