三星 Galaxy S10 的密度 DPI 太小？

Question

I've been getting device density like this:

val wm = getSystemService(Context.WINDOW_SERVICE) as WindowManager
val display = wm.defaultDisplay
val metrics = DisplayMetrics()
display.getMetrics(metrics)
val density = metrics.densityDpi

Then I based some logic on the value of density and constants:

• DENSITY_XHIGH
• DENSITY_XXHIGH

I expected S10 to fall under DENSITY_XXHIGH but apparently it's density value is 420 , contrary to S9 which density is 480 .

1. Does that mean that S10 is actually using resources from xhdpi and not xxhdpi folder?
2. If this value is not reliable what value should I base on my logic for choosing optimal image size before I load int into ImageView ?

Answer 1

If you want to know what is used, I suggest to create a "whoami" string and place it in values-xhdpi and all other *dpi variants.

values-xhdpi/whoami.xml

<resources>
    <string name="density_bucket" translatable="false">xhdpi</string>
</resources>

If you use that value, you know what the Android system selects from during runtime.

As this is a nice way for "debugging" your question to a specific device, you can also adopt to this. In my case this value is used to request the right image sizes from an asset backend.