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

遵循以下方法:

public static int getWidthScreen(Context context) {
    return getDisplayMetrics(context).widthPixels;
}

public static int getHeightScreen(Context context) {
    return getDisplayMetrics(context).heightPixels;
}

private static DisplayMetrics getDisplayMetrics(Context context) {
    DisplayMetrics displayMetrics = new DisplayMetrics();
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    wm.getDefaultDisplay().getMetrics(displayMetrics);
    return displayMetrics;
}

其他回答

如果Display类不工作,则上面的答案将不起作用,那么您可以通过下面的方法获得宽度和高度。

private static final int WIDTH_INDEX = 0;
private static final int HEIGHT_INDEX = 1;

    public static int[] getScreenSize(Context context) {
        int[] widthHeight = new int[2];
        widthHeight[WIDTH_INDEX] = 0;
        widthHeight[HEIGHT_INDEX] = 0;

        try {
            WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
            Display display = windowManager.getDefaultDisplay();

            Point size = new Point();
            display.getSize(size);
            widthHeight[WIDTH_INDEX] = size.x;
            widthHeight[HEIGHT_INDEX] = size.y;

            if (!isScreenSizeRetrieved(widthHeight))
            {
                DisplayMetrics metrics = new DisplayMetrics();
                display.getMetrics(metrics);
                widthHeight[0] = metrics.widthPixels;
                widthHeight[1] = metrics.heightPixels;
            }

            // Last defense. Use deprecated API that was introduced in lower than API 13
            if (!isScreenSizeRetrieved(widthHeight)) {
                widthHeight[0] = display.getWidth(); // deprecated
                widthHeight[1] = display.getHeight(); // deprecated
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return widthHeight;
    }

    private static boolean isScreenSizeRetrieved(int[] widthHeight) {
        return widthHeight[WIDTH_INDEX] != 0 && widthHeight[HEIGHT_INDEX] != 0;
    }
public class AndroidScreenActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        DisplayMetrics dm = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(dm);
        String str_ScreenSize = "The Android Screen is: "
                                   + dm.widthPixels
                                   + " x "
                                   + dm.heightPixels;

        TextView mScreenSize = (TextView) findViewById(R.id.strScreenSize);
        mScreenSize.setText(str_ScreenSize);
    }
}

它可能无法回答您的问题,但如果你需要一个视图的维度,但你的代码在尚未布局时(例如在onCreate()中)正在执行,你可以使用View.getViewTreeObserver().addOnGlobalLayoutListener()设置一个ViewTreeObserver.OnGlobalLayout侦听器,并将需要该视图的相关代码放入尺寸。布局布局完成后,将调用侦听器的回调。

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 ...
}

对于正在搜索没有状态栏和操作栏的可用屏幕尺寸的用户(也感谢Swapnil的回答):

DisplayMetrics dm = getResources().getDisplayMetrics();
float screen_w = dm.widthPixels;
float screen_h = dm.heightPixels;

int resId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resId > 0) {
    screen_h -= getResources().getDimensionPixelSize(resId);
}

TypedValue typedValue = new TypedValue();
if(getTheme().resolveAttribute(android.R.attr.actionBarSize, typedValue, true)){
    screen_h -= getResources().getDimensionPixelSize(typedValue.resourceId);
}