iOS 只取float类型值的小数点后两位

[self.btnEco setTitle:[NSString stringWithFormat:@"%0.1f",model.targetTemperature] forState:UIControlStateNormal];

float floatValue=123.0000
NSString *strValue=[NSString stringWithFormat:@"%0.2f", floatValue];

不用截取字符的方法，取两位小数得到123.00

需要小数点后n位数字就％0.nf