iOS 人民幣單位轉換，元 轉 萬元 轉 億，等等。

- (NSString *)getDealNumwithstring:(NSString *)string withNumCount:(NSInteger)integer{
    
    
    NSDecimalNumber *numberA = [NSDecimalNumber decimalNumberWithString:string];
    NSDecimalNumber *numberB ;
    if (integer == 4) {
        numberB =  [NSDecimalNumber decimalNumberWithString:@"10000"];
    } else if (integer == 8){
        numberB =  [NSDecimalNumber decimalNumberWithString:@"100000000"];
    }else{
        numberB =  [NSDecimalNumber decimalNumberWithString:@"10000"];
    }
    //NSDecimalNumberBehaviors對象的創建  參數 1.RoundingMode 一個取舍枚舉值 2.scale 處理范圍 3.raiseOnExactness  精確出現異常是否拋出原因 4.raiseOnOverflow  上溢出是否拋出原因  4.raiseOnUnderflow  下溢出是否拋出原因  5.raiseOnDivideByZero  除以0是否拋出原因。
    NSDecimalNumberHandler *roundingBehavior = [NSDecimalNumberHandler decimalNumberHandlerWithRoundingMode:NSRoundDown scale:2 raiseOnExactness:NO raiseOnOverflow:NO raiseOnUnderflow:NO raiseOnDivideByZero:NO];
    
    /// 這里不僅包含Multiply還有加 減 乘。
    NSDecimalNumber *numResult = [numberA decimalNumberByDividingBy:numberB withBehavior:roundingBehavior];
    NSString *strResult = [numResult stringValue];
    return strResult;
}