显示一个代码块：看了设置里面的才发现是这样用的，下面试试来段代码:(这行下面必须有个空行，然后代码块的开始是缩进4 个空格或是 1 个制表符)
@property (strong, nonatomic) NSString *descriptiveVariableName;
@property (strong, nonatomic) UIImage *image;
来个长点的：
- (void)sendAction:(SEL)aSelector to:(id)anObject forAllCells:(BOOL)flag; //add some comments to make it longer to view