zhengjiajie_2009的专栏

一、NSString字符串连接 NSString* string; // 结果字符串 NSString* string1, string2; //已存在的字符串 1. string = [NSString initWithFormat:@"%@,%@", string1, string2 ]; 2. string = [string1 stringByAppendingString

1：如果无法保证子类行为的一致性，那么就用委托 If the subClass cann't keep with superClass,use delegate rather than inheritance.   2:屏幕上看到的，都是UIVew Everything you see on Screen is UIView.

1、在h文件中定义，第一个按钮对应-(IBAction)  addButton:(id)sender; 并在m文件中实现它。    -(IBAction)addButton:(id)sender{     CGRect frame = CGRectMake(90, 200, 200, 60);     UIButton *someAddButton = [UIButton bu