如果你想从服务中检索密度，它是这样工作的:

WindowManager wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics metrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(metrics);

另一种获得设备加载密度的方法:

为每个密度创建值文件夹

值(默认mdpi) values-hdpi values-xhdpi values-xxhdpi values-xxxhdpi

在它们各自的strings.xml中添加一个字符串资源:

<string name="screen_density">MDPI</string>    <!-- ..\res\values\strings.xml -->
<string name="screen_density">HDPI</string>    <!-- ..\res\values-hdpi\strings.xml -->
<string name="screen_density">XHDPI</string>   <!-- ..\res\values-xhdpi\strings.xml -->
<string name="screen_density">XXHDPI</string>  <!-- ..\res\values-xxhdpi\strings.xml -->
<string name="screen_density">XXXHDPI</string> <!-- ..\res\values-xxxhdpi\strings.xml -->

然后简单地获取字符串资源，你就有了密度:

String screenDensity = getResources().getString(R.string.screen_density);

如果密度大于XXXHDPI，它将默认为XXXHDPI，如果密度低于HDPI，它将默认为MDPI

我省略了LDPI，因为对于我的用例来说它是不必要的。

如果你想从服务中检索密度，它是这样工作的:

WindowManager wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics metrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(metrics);

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);

switch(metrics.densityDpi) {
     case DisplayMetrics.DENSITY_LOW:
         break;

     case DisplayMetrics.DENSITY_MEDIUM:
         break;

     case DisplayMetrics.DENSITY_HIGH:
         break;
}

这将在API级别4和更高的级别上工作。

你应该试试这个。刚刚添加了一个方法，它将找到并显示吐司。设备属于哪个类别。

public static int differentDensityAndScreenSize(Context context) {
  int value = 20;
  String str = "";
  if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_SMALL) {
   switch (context.getResources().getDisplayMetrics().densityDpi) {
   case DisplayMetrics.DENSITY_LOW:
    str = "small-ldpi";
    value = 20;
    break;
   case DisplayMetrics.DENSITY_MEDIUM:
    str = "small-mdpi";
    value = 20;
    break;
   case DisplayMetrics.DENSITY_HIGH:
    str = "small-hdpi";
    value = 20;
    break;
   case DisplayMetrics.DENSITY_XHIGH:
    str = "small-xhdpi";
    value = 20;
    break;
   case DisplayMetrics.DENSITY_XXHIGH:
    str = "small-xxhdpi";
    value = 20;
    break;
   case DisplayMetrics.DENSITY_XXXHIGH:
    str = "small-xxxhdpi";
    value = 20;
    break;
   case DisplayMetrics.DENSITY_TV:
    str = "small-tvdpi";
    value = 20;
    break;
   default:
    str = "small-unknown";
    value = 20;
    break;
   }

  } else if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_NORMAL) {
   switch (context.getResources().getDisplayMetrics().densityDpi) {
   case DisplayMetrics.DENSITY_LOW:
    str = "normal-ldpi";
    value = 82;
    break;
   case DisplayMetrics.DENSITY_MEDIUM:
    str = "normal-mdpi";
    value = 82;
    break;
   case DisplayMetrics.DENSITY_HIGH:
    str = "normal-hdpi";
    value = 82;
    break;
   case DisplayMetrics.DENSITY_XHIGH:
    str = "normal-xhdpi";
    value = 90;
    break;
   case DisplayMetrics.DENSITY_XXHIGH:
    str = "normal-xxhdpi";
    value = 96;
    break;
   case DisplayMetrics.DENSITY_XXXHIGH:
    str = "normal-xxxhdpi";
    value = 96;
    break;
   case DisplayMetrics.DENSITY_TV:
    str = "normal-tvdpi";
    value = 96;
    break;
   default:
    str = "normal-unknown";
    value = 82;
    break;
   }
  } else if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_LARGE) {
   switch (context.getResources().getDisplayMetrics().densityDpi) {
   case DisplayMetrics.DENSITY_LOW:
    str = "large-ldpi";
    value = 78;
    break;
   case DisplayMetrics.DENSITY_MEDIUM:
    str = "large-mdpi";
    value = 78;
    break;
   case DisplayMetrics.DENSITY_HIGH:
    str = "large-hdpi";
    value = 78;
    break;
   case DisplayMetrics.DENSITY_XHIGH:
    str = "large-xhdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_XXHIGH:
    str = "large-xxhdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_XXXHIGH:
    str = "large-xxxhdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_TV:
    str = "large-tvdpi";
    value = 125;
    break;
   default:
    str = "large-unknown";
    value = 78;
    break;
   }

  } else if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
   switch (context.getResources().getDisplayMetrics().densityDpi) {
   case DisplayMetrics.DENSITY_LOW:
    str = "xlarge-ldpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_MEDIUM:
    str = "xlarge-mdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_HIGH:
    str = "xlarge-hdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_XHIGH:
    str = "xlarge-xhdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_XXHIGH:
    str = "xlarge-xxhdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_XXXHIGH:
    str = "xlarge-xxxhdpi";
    value = 125;
    break;
   case DisplayMetrics.DENSITY_TV:
    str = "xlarge-tvdpi";
    value = 125;
    break;
   default:
    str = "xlarge-unknown";
    value = 125;
    break;
   }
  }
// The Toast will show the Device falls in Which Categories.
Toast.makeText(MainActivity.this, ""+str, Toast.LENGTH_SHORT).show();

  return value;
 }

http://www.androidwarriors.com/2016/01/how-to-find-different-devices-screen.html

科特林

LocalContext.current.resources.displayMetrics.density

得到密度乘数。