UITextField 隻能輸入字母、數字的方法小結

在IOS實際開發中有些UITextField需要限制輸入内容，如賬号、密碼等，下面簡單介紹其簡單的實作方法，如下：

代碼實作

//定義宏（限制輸入内容） #define kAlphaNum  @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" #define kAlpha      @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz " #define kNumbers     @"0123456789" #define kNumbersPeriod  @"0123456789." //定義UITextFiled的代理方法： - (BOOL)textField:(UITextField *)textField     shouldChangeCharactersInRange:(NSRange)range     replacementString:(NSString *)string {     NSCharacterSet *cs;     cs = [[NSCharacterSet characterSetWithCharactersInString:kAlphaNum] invertedSet];     NSString *filtered =     [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];     BOOL basic = [string isEqualToString:filtered];     return basic; }