android - Google Material Design 图标 - 从相应的可绘制文件夹中使用哪个文件(18dp、24、36 和 48)

Question

Google Material Design 图标 https://github.com/google/material-design-icons ，注意在每个文件夹下，即(drawable-hdpi、drawable-mdpi 等)至少有 4 组文件.. 如下所示..

我想知道在布局中将它们用作 ImageButton 时，应该在 android:src 属性中引用哪个文件，以及它背后的逻辑是什么。假设应用程序必须支持 4 英寸、5 英寸和 10 英寸屏幕尺寸。可能有人解释了这 4 种文件的用途。

-rw-r--r-- 1 girishkhatri 197121 111 Jul 26 22:27 ./navigation/drawable-hdpi/ic_menu_black_18dp.png
-rw-r--r-- 1 girishkhatri 197121  94 Jul 26 22:27 ./navigation/drawable-hdpi/ic_menu_black_24dp.png
-rw-r--r-- 1 girishkhatri 197121 105 Jul 26 22:27 ./navigation/drawable-hdpi/ic_menu_black_36dp.png
-rw-r--r-- 1 girishkhatri 197121 111 Jul 26 22:27 ./navigation/drawable-hdpi/ic_menu_black_48dp.png

-rw-r--r-- 1 girishkhatri 197121  81 Jul 26 22:27 ./navigation/drawable-mdpi/ic_menu_black_18dp.png
-rw-r--r-- 1 girishkhatri 197121  82 Jul 26 22:27 ./navigation/drawable-mdpi/ic_menu_black_24dp.png
-rw-r--r-- 1 girishkhatri 197121  94 Jul 26 22:27 ./navigation/drawable-mdpi/ic_menu_black_36dp.png
-rw-r--r-- 1 girishkhatri 197121  99 Jul 26 22:27 ./navigation/drawable-mdpi/ic_menu_black_48dp.png

-rw-r--r-- 1 girishkhatri 197121  94 Jul 26 22:27 ./navigation/drawable-xhdpi/ic_menu_black_18dp.png
-rw-r--r-- 1 girishkhatri 197121  99 Jul 26 22:27 ./navigation/drawable-xhdpi/ic_menu_black_24dp.png
-rw-r--r-- 1 girishkhatri 197121 111 Jul 26 22:27 ./navigation/drawable-xhdpi/ic_menu_black_36dp.png
-rw-r--r-- 1 girishkhatri 197121 116 Jul 26 22:27 ./navigation/drawable-xhdpi/ic_menu_black_48dp.png

-rw-r--r-- 1 girishkhatri 197121 105 Jul 26 22:27 ./navigation/drawable-xxhdpi/ic_menu_black_18dp.png
-rw-r--r-- 1 girishkhatri 197121 111 Jul 26 22:27 ./navigation/drawable-xxhdpi/ic_menu_black_24dp.png
-rw-r--r-- 1 girishkhatri 197121 117 Jul 26 22:27 ./navigation/drawable-xxhdpi/ic_menu_black_36dp.png
-rw-r--r-- 1 girishkhatri 197121 127 Jul 26 22:27 ./navigation/drawable-xxhdpi/ic_menu_black_48dp.png

-rw-r--r-- 1 girishkhatri 197121 111 Jul 26 22:27 ./navigation/drawable-xxxhdpi/ic_menu_black_18dp.png
-rw-r--r-- 1 girishkhatri 197121 116 Jul 26 22:27 ./navigation/drawable-xxxhdpi/ic_menu_black_24dp.png
-rw-r--r-- 1 girishkhatri 197121 127 Jul 26 22:27 ./navigation/drawable-xxxhdpi/ic_menu_black_36dp.png
-rw-r--r-- 1 girishkhatri 197121 129 Jul 26 22:27 ./navigation/drawable-xxxhdpi/ic_menu_black_48dp.png

Answer 1

在 https://google.github.io/material-design-icons 获得了图标的详细信息和用途和 https://developer.android.com/guide/practices/screens_support.html默认为24

Sizing

Although the icons in the font can be scaled to any size, in accordance with >material design icons guidelines, we recommend them to be shown in either 18, 24, 36 or 48px. The default being 24px