Android碎片化知识管理

• android图标ic_launcher大小

  • drawable-hdpi/ic_launcher.png (72x72 px)

  • drawable-mdpi/ic_launcher.png (48x48 px)

  • drawable-xhdpi/ic_launcher.png (96x96 px)

  • drawable-xxhdpi/ic_launcher.png (144x144 px)

• String字符串的操作

  /*
  * String字符串的截取
  */
  String string = "abcdefghijklmnopqrstuvwxyz";
  String subString = string.substring(0, 3);//结果：subString="abc"