小技能---记录📝

- (BOOL)textField:(UITextField*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string {return[selfvalidateNumber:string];}- (BOOL)validateNumber:(NSString*)number {BOOLres =YES;NSCharacterSet* tmpSet = [NSCharacterSetcharacterSetWithCharactersInString:@"0123456789"];inti =0;while(i < number.length) {NSString* string = [number substringWithRange:NSMakeRange(i,1)];NSRangerange = [string rangeOfCharacterFromSet:tmpSet];if(range.length ==0) { res =NO;break; } i++; }returnres;}

只允许键盘输入数字（包括系统键盘或者用户安装了第三方自定义花样键盘）

 [UIApplication sharedApplication].idleTimerDisabled = YES。

设置禁止手机屏幕变暗.