为什么不

DisplayMetrics displaymetrics = getResources().getDisplayMetrics();

然后使用

displayMetrics.widthPixels

and

displayMetrics.heightPixels

在Android中很容易获得:

int width  = Resources.getSystem().getDisplayMetrics().widthPixels;
int height = Resources.getSystem().getDisplayMetrics().heightPixels;

    int getScreenSize() {
        int screenSize = getResources().getConfiguration().screenLayout &
                Configuration.SCREENLAYOUT_SIZE_MASK;
//        String toastMsg = "Screen size is neither large, normal or small";
        Display display = ((WindowManager) getSystemService(WINDOW_SERVICE)).getDefaultDisplay();
        int orientation = display.getRotation();

        int i = 0;
        switch (screenSize) {

            case Configuration.SCREENLAYOUT_SIZE_NORMAL:
                i = 1;
//                toastMsg = "Normal screen";
                break;
            case Configuration.SCREENLAYOUT_SIZE_SMALL:
                i = 1;
//                toastMsg = "Normal screen";
                break;
            case Configuration.SCREENLAYOUT_SIZE_LARGE:
//                toastMsg = "Large screen";
                if (orientation == Surface.ROTATION_90
                        || orientation == Surface.ROTATION_270) {
                    // TODO: add logic for landscape mode here
                    i = 2;
                } else {
                    i = 1;
                }


                break;
            case Configuration.SCREENLAYOUT_SIZE_XLARGE:
                if (orientation == Surface.ROTATION_90
                        || orientation == Surface.ROTATION_270) {
                    // TODO: add logic for landscape mode here
                    i = 4;
                } else {
                    i = 3;
                }

                break;


        }
//        customeToast(toastMsg);
        return i;
    }

•Kotlin版本通过扩展属性

如果你想知道屏幕的像素大小以及dp，使用这些扩展属性真的很有帮助:

DimensionUtils.kt

import android.content.Context
import android.content.res.Resources
import android.graphics.Rect
import android.graphics.RectF
import android.os.Build
import android.util.DisplayMetrics
import android.view.WindowManager
import kotlin.math.roundToInt

/**
 * @author aminography
 */

private val displayMetrics: DisplayMetrics by lazy { Resources.getSystem().displayMetrics }

/**
 * Returns boundary of the screen in pixels (px).
 */
val screenRectPx: Rect
    get() = displayMetrics.run { Rect(0, 0, widthPixels, heightPixels) }

/**
 * Returns boundary of the screen in density independent pixels (dp).
 */
val screenRectDp: RectF
    get() = screenRectPx.run { RectF(0f, 0f, right.px2dp, bottom.px2dp) }

/**
 * Returns boundary of the physical screen including system decor elements (if any) like navigation
 * bar in pixels (px).
 */
val Context.physicalScreenRectPx: Rect
    get() = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        (applicationContext.getSystemService(Context.WINDOW_SERVICE) as WindowManager)
            .run { DisplayMetrics().also { defaultDisplay.getRealMetrics(it) } }
            .run { Rect(0, 0, widthPixels, heightPixels) }
    } else screenRectPx

/**
 * Returns boundary of the physical screen including system decor elements (if any) like navigation
 * bar in density independent pixels (dp).
 */
val Context.physicalScreenRectDp: RectF
    get() = physicalScreenRectPx.run { RectF(0f, 0f, right.px2dp, bottom.px2dp) }

/**
 * Converts any given number from pixels (px) into density independent pixels (dp).
 */
val Number.px2dp: Float
    get() = this.toFloat() / displayMetrics.density

/**
 * Converts any given number from density independent pixels (dp) into pixels (px).
 */
val Number.dp2px: Int
    get() = (this.toFloat() * displayMetrics.density).roundToInt()

用法:

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val widthPx = screenRectPx.width()
        val heightPx = screenRectPx.height()
        println("[PX] screen width: $widthPx , height: $heightPx")

        val widthDp = screenRectDp.width()
        val heightDp = screenRectDp.height()
        println("[DP] screen width: $widthDp , height: $heightDp")

        println()
        
        val physicalWidthPx = physicalScreenRectPx.width()
        val physicalHeightPx = physicalScreenRectPx.height()
        println("[PX] physical screen width: $physicalWidthPx , height: $physicalHeightPx")

        val physicalWidthDp = physicalScreenRectDp.width()
        val physicalHeightDp = physicalScreenRectDp.height()
        println("[DP] physical screen width: $physicalWidthDp , height: $physicalHeightDp")
    }
}

结果:

当设备处于纵向方向时:

[PX] screen width: 1440 , height: 2392
[DP] screen width: 360.0 , height: 598.0

[PX] physical screen width: 1440 , height: 2560
[DP] physical screen width: 360.0 , height: 640.0

当设备处于横向时:

[PX] screen width: 2392 , height: 1440
[DP] screen width: 598.0 , height: 360.0

[PX] physical screen width: 2560 , height: 1440
[DP] physical screen width: 640.0 , height: 360.0

DisplayMetrics dimension = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(dimension);
        int width = dimension.widthPixels;
        int height = dimension.heightPixels;

正如android官方文档所说，默认显示使用Context#getDisplay()，因为该方法在API级别30中已弃用。

.getDefaultDisplay getWindowManager () () .getMetrics (displayMetrics);

这一碗代码有助于确定宽度和高度。

public static int getWidth(Context context) {
    DisplayMetrics displayMetrics = new DisplayMetrics();
    Display display = context.getDisplay();
    if (display != null) {
        display.getRealMetrics(displayMetrics);
        return displayMetrics.widthPixels;
    }
    return -1;
}

关于高度:

public static int getHeight(Context context) {
    DisplayMetrics displayMetrics = new DisplayMetrics();
    Display display = context.getDisplay();
    if (display != null) {
        display.getRealMetrics(displayMetrics);
        return displayMetrics.heightPixels;
    }
    return -1;
}