修改权限
修改Xcode里快捷键的配置文件(plist)权限，打开终端输入如下两条命令:
sudo chmod 666 /Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Resources/IDETextKeyBindingSet.plist
sudo chmod 777 /Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Resources/
打开plist 文件
open /Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Resources/IDETextKeyBindingSet.plist
删除整行
然后找到root下的Deletions，在Deletions下添加一个key：Delete Current Line值为：
deleteToBeginningOfLine:, moveToEndOfLine:, deleteToBeginningOfLine:, deleteBackward:
复制整行和在下方添加一行
在Insertions and Indentations下添加两个key：
Duplicate Current Line 值为：selectLine:, copy:, moveLeft:, moveToEndOfLine:, insertNewline:, paste:, deleteBackward:
Insert Line Under 值为： moveToEndOfLine:, insertNewline:
