【android】android icon大小设计规范

Check out Google's official Material Design guidelines for Icons about two thirds of the way down the page under the sub-heading Corners.
It indicates you should use a 2px radius on the corners. If go up a few sections, under the heading Content Area you'll see this is for a 24x24 px icon. You can scale up for other resolutions from there.

By scaling appropriately, we get the following: LDPI should be 36 x 36 = 3px radius, MDPI should be 48 x 48 = 4px radius, TVDPI should be 64 x 64 = 5px radius, HDPI should be 72 x 72 = 6px radius, XHDPI should be 96 x 96 = 8px radius, XXHDPI should be 144 x 144 = 12px radius, XXXHDPI should be 192 x 192 = 16px radius.

The radius of the corners should be 8.33% of the size of the icon according to Materiel guidelines.

So if the size of your icon in your project is: 1000px by 1000px, then the corner radius should be 83.3px.