在[http://www.imooc.com/qadetail/70235]裡提到了根據谷歌官方的內容，於是自己查了一下。

在第④點中說明了

mipmap用於放啟動圖示，

drawable用於放各種資源，

和網上好多人糾正的一樣，記錄一下。

①在“Android 4.3 APIs”（https://developer.android.com/about/versions/android-4.3.html）

寫到

Mipmapping for drawables
Using a mipmap as the source for your bitmap or drawable is a simple way to provide a quality image and various image scales, which can be particularly useful if you expect your image to be scaled during an animation.


Android 4.2 (API level 17) added support for mipmaps in the Bitmap class—Android swaps the mip images in your Bitmap when you've supplied a mipmap source and have enabled setHasMipMap(). Now in Android 4.3, you can enable mipmaps for a BitmapDrawable object as well, by providing a mipmap asset and setting the android:mipMap attribute in a bitmap resource file or by calling hasMipMap().

②在“Add Bitmap Images with Image Asset Studio”（https://developer.android.com/studio/write/image-asset-studio.html#mipmap）

Managing Launcher Icons as mipmap Resources
Different home screen launcher apps on different devices show app launcher icons at various resolutions. When app resource optimization techniques remove resources for unused screen densities, launcher icons can wind up looking fuzzy because the launcher app has to upscale a lower-resolution icon for display. To avoid these display issues, apps should use the mipmap/ resource folders for launcher icons. The Android system preserves these resources regardless of density stripping, and ensures that launcher apps can pick icons with the best resolution for display.


Make sure launcher apps show a high-resolution icon for your app by moving all densities of your launcher icons to density-specific res/mipmap/ folders (for example res/mipmap-mdpi/ and res/mipmap-xxxhdpi/). The mipmap/ folders replace the drawable/ folders for launcher icons. For xxhpdi launcher icons, be sure to add the higher resolution xxxhdpi versions of the icons to enhance the visual experience of the icons on higher resolution devices.


Note: Even if you build a single APK for all devices, it is still best practice to move your launcher icons to the mipmap/ folders.

③在“Using configuration qualifiers”（https://developer.android.com/guide/practices/screens_support.html#qualifiers）

For example, the following application resource directories provide different layout designs for different screen sizes and different drawables. Use the mipmap/ folders for launcher icons.


res/layout/my_layout.xml              // layout for normal screen size ("default")
res/layout-large/my_layout.xml        // layout for large screen size
res/layout-xlarge/my_layout.xml       // layout for extra-large screen size
res/layout-xlarge-land/my_layout.xml  // layout for extra-large in landscape orientation


res/drawable-mdpi/graphic.png         // bitmap for medium-density
res/drawable-hdpi/graphic.png         // bitmap for high-density
res/drawable-xhdpi/graphic.png        // bitmap for extra-high-density
res/drawable-xxhdpi/graphic.png       // bitmap for extra-extra-high-density


res/mipmap-mdpi/my_icon.png         // launcher icon for medium-density
res/mipmap-hdpi/my_icon.png         // launcher icon for high-density
res/mipmap-xhdpi/my_icon.png        // launcher icon for extra-high-density
res/mipmap-xxhdpi/my_icon.png       // launcher icon for extra-extra-high-density
res/mipmap-xxxhdpi/my_icon.png      // launcher icon for extra-extra-extra-high-density
For more information about how to use alternative resources and a complete list of configuration qualifiers (not just for screen configurations), see Providing Alternative Resources.

④在“Providing Resources”（https://developer.android.com/guide/topics/resources/providing-resources.html#ResourceTypes）

As you can see in this example, the res/ directory contains all the resources (in subdirectories): an image resource, two layout resources, mipmap/ directories for launcher icons, and a string resource file. The resource directory names are important and are described in table 1.

drawable/
Bitmap files (.png, .9.png, .jpg, .gif) or XML files that are compiled into the following drawable resource subtypes:
Bitmap files
Nine-Patches (re-sizable bitmaps)
State lists
Shapes
Animation drawables
Other drawables
See Drawable Resources.




mipmap/
Drawable files for different launcher icon densities. For more information on managing launcher icons with mipmap/ folders, see Managing Projects Overview.