- (NSString*)notRounding:(CGFloat)price afterPoint:(NSInteger)position {

NSDecimalNumberHandler*roundingBehavior = [NSDecimalNumberHandlerdecimalNumberHandlerWithRoundingMode:NSRoundDownscale:positionraiseOnExactness:NOraiseOnOverflow:NOraiseOnUnderflow:NOraiseOnDivideByZero:NO];

NSDecimalNumber*ouncesDecimal;

NSDecimalNumber*roundedOunces;

ouncesDecimal = [[NSDecimalNumberalloc]initWithFloat:price];

roundedOunces = [ouncesDecimaldecimalNumberByRoundingAccordingToBehavior:roundingBehavior];

return[NSStringstringWithFormat:@"%@",roundedOunces];

}

使用方法：

floats =0.126;

NSString*sb = [selfnotRounding:s afterPoint:2];

NSLog(@"sb = %@",sb);

输出结果为：sb = 0.12

接下来介绍NSDecimalNumberHandler初始化时的关键参数：decimalNumberHandlerWithRoundingMode：NSRoundDown，

NSRoundDown代表的就是只舍不入。

scale的参数position代表保留小数点后几位。