将基本脚本转换为 Objective C（货币格式）

Question

我有这个基本的类似脚本，我需要将其转换为 Objective C，它将大单位的金钱转换为缩短的版本（即：1.2m 等），我已经完成了大部分转换，但最大的问题是我我就在最后。

原始基本代码为：

; Basic Code

Function ShortCash$(BigNumber)
out$=""


    ; First, grab the length of the number
    L=Len(BigNumber)

    Letter$=""

    ;Next, Do a sweep of the values, and cut them down.
        If l<13 
            out$=(BigNumber/1000000000)

            ; For each figure, out remainder should be divided so that it leaves a 2 digit decimal number..
            remainder=(BigNumber Mod 1000000000)/10000000

            ; And we also want a letter to symbolise our large amounts..
            Letter$="b" ; BILLION!!!!
        EndIf
        If l<10 Then out$=(BigNumber/1000000):remainder=(BigNumber Mod 1000000)/10000:Letter$="m"
        If l<7 Then out$=(BigNumber/1000):remainder=(BigNumber Mod 1000)/10:Letter$="k"
        If l<4 Then out$=BigNumber:remainder=0:Letter$=""

    ;Next, if remainder=0 then we're happy..  ie, £1m is fine, we need no decimal.
    ;But, if the remainder is >0 we'll want a nice rounded 2 decimal number, instead.
    If remainder>0
        out$=out$+"."+Right$("00"+remainder,2) ; Last two numbers..

        ; Additionally, if the rightmost figure is a 0, remove it.
        ; (ie, if the value is 1.50, we don't need the 0)
        If Right$(out$,1)="0" Then out$=Left$(out$,Len(out$)-1)

    EndIf


    ; And throw on our letter, at the end.
    out$=out$+letter$ 

Return out$
End Function

// 以下内容由帖子作者于 8 月 5 日星期四编辑。

我相信我现在已经解决了，目前我已经为数千人提供了以下内容，我不确定它是否在所有情况下都有效，并欢迎对此提供任何帮助/指导。我知道内存问题，稍后我会解决这个问题，这是我首先解决的字符串操作部分。

// This goes inside the (IBAction) update method;

    NSNumber *bigNumber = nil;

    if ( [inputField.text length] >0)
    {
        bigNumber = [NSNumber numberWithInt:[inputField.text intValue]];
    }

    int bigNumberAsInt          = [bigNumber intValue];
    NSString *bigNumberAsString = [bigNumber stringValue];
    int bigNumberStrLen         = [bigNumberAsString length];

    NSLog(@"bigNumber = %@", bigNumber);
    //NSLog(@"bigNumberAsString = %@", bigNumberAsString);
    NSLog(@"bigNumberStrLen = %d", bigNumberStrLen);
    NSLog(@"=========");

    // =========

    NSNumberFormatter *nformat = [[[NSNumberFormatter alloc] init] autorelease];

    [nformat setFormatterBehavior:NSNumberFormatterBehavior10_4];
    [nformat setCurrencySymbol:@"$"];
    [nformat setNumberStyle:NSNumberFormatterCurrencyStyle];
    [nformat setMaximumFractionDigits:0];

    NSLog(@"Cash = %@", [nformat stringFromNumber:bigNumber]);

    // =========


    NSString *output = [[NSString alloc] init]; 
    NSString *letter;


    // ==========

    // Anything less than 1m represent with a k
    if (bigNumberStrLen < 7) 
    {
        letter = @"k";
        int sum = (bigNumberAsInt / 1000);
        int int_remainder = ((bigNumberAsInt % 1000) / 10);

        NSLog(@"Remainder = %d", int_remainder);

        NSString *sumAsString = [NSString stringWithFormat:@"%d", sum];
        NSString *remainderAsString = [NSString stringWithFormat:@"%d", int_remainder];

        NSLog(@"Sum as String = %@", sumAsString);
        NSLog(@"Remainder as String = %@", remainderAsString);

        if (int_remainder >0)
        {
            NSLog(@"Remainder > 0");

            output = [output stringByAppendingString:sumAsString];
            output = [output stringByAppendingString:@"."];
            output = [output stringByAppendingString:remainderAsString];

            NSLog(@"Output = %@", output);

            NSUInteger outputStrLen = [output length];

            NSLog(@"Output strlen = %d", outputStrLen);

            if ([output hasSuffix:@"0"])
            {
                NSLog(@"Has suffix of 0");

                // Remove suffix
                output = [output substringWithRange: NSMakeRange(0, outputStrLen-1)];
            }

        }

        output = [output stringByAppendingString:letter];

        NSLog(@"Final output = %@", output);


    }

这将显示 10.2k（如果以 0 后缀结尾），或者将显示 10.2x，其中 X 是最后一个数字。

有人可以仔细检查一下吗，或者也许有一种更简单的方法来完成这一切。无论哪种情况，感谢您的帮助。

Answer 1

为了改进解决方案，一个好主意可能是对 NSNumberFormatter 类进行子类化并重写 - (NSString *)stringForObjectValue:(id)anObject 方法。

使用 zardon 的代码，我添加了一个值 << 的语句。 1000 不格式化数字。

这是该方法的代码：

/*
    Override the stringForObjectValue method from NSNumberFormatter

    100 -> 100
    1000 -> 1k
    1 000 000 -> 1m
    1 000 000 000 -> 1b
    1 000 000 000 -> 1t
 */
- (NSString *)stringForObjectValue:(id)anObject {

    // If we don't get a NSNumber, we can't create the string
    if (![anObject isKindOfClass:[NSNumber class]]) {
        return nil;
    }

    NSNumberFormatter *nformat = [[NSNumberFormatter alloc] init];

    // Decimal value from the NSObject
    double doubleValue = [anObject doubleValue];

    NSString *stringValue = nil;

    // Abbrevations used
    NSArray *abbrevations = [NSArray arrayWithObjects:@"k", @"m", @"b", @"t", nil] ;

    // If the value is less than 1000, we display directly the value
    if(doubleValue < 1000.0) {
        stringValue = [NSString stringWithFormat: @"%@", [nformat stringFromNumber: [NSNumber numberWithDouble: doubleValue]] ];
    }
    else { // Otherwise we format it as expected
        for (NSString *s in abbrevations) {
            doubleValue /= 1000.0 ;

            if ( doubleValue < 1000.0 ) {

                if ( (long long)doubleValue % (long long) 100 == 0 ) {
                    [nformat setMaximumFractionDigits:0];
                } else {                
                    [nformat setMaximumFractionDigits:2];
                }

                stringValue = [NSString stringWithFormat: @"%@", [nformat stringFromNumber: [NSNumber numberWithDouble: doubleValue]] ];
                NSUInteger stringLen = [stringValue length];

                if ( [stringValue hasSuffix:@".00"] )
                {               
                    // Remove suffix
                    stringValue = [stringValue substringWithRange: NSMakeRange(0, stringLen-3)];            
                } else if ( [stringValue hasSuffix:@".0"] ) {

                    // Remove suffix
                    stringValue = [stringValue substringWithRange: NSMakeRange(0, stringLen-2)];

                } else if ( [stringValue hasSuffix:@"0"] ) {

                    // Remove suffix
                    stringValue = [stringValue substringWithRange: NSMakeRange(0, stringLen-1)];        
                }

                // Add the letter suffix at the end of it
                stringValue = [stringValue stringByAppendingString: s];

                break;
            }   
        }
    }

    [nformat release];

    return stringValue;
}

在接口中我们只需添加继承语句：

@interface MoneyNumberFormatter : NSNumberFormatter

希望这会有所帮助..

Answer 2

....好的，感谢 Cocoa Tidbits 博客，我相信我有一个更优雅、更快并且不需要那么多编码的解决方案；它仍然需要测试，并且可能还需要更多的编辑，但它似乎比我原来的要好得多。

我对脚本进行了一些修改，使其不显示任何相关的尾随零；

    NSNumberFormatter *nformat = [[NSNumberFormatter alloc] init];
    [nformat setFormatterBehavior:NSNumberFormatterBehavior10_4];
    [nformat setCurrencySymbol:@"$"];
    [nformat setNumberStyle:NSNumberFormatterCurrencyStyle];
    double doubleValue = 10200;
    NSString *stringValue = nil;
    NSArray *abbrevations = [NSArray arrayWithObjects:@"k", @"m", @"b", @"t", nil] ;

    for (NSString *s in abbrevations)
    {

        doubleValue /= 1000.0 ;

        if ( doubleValue < 1000.0 )
        {

            if ( (long long)doubleValue % (long long) 100 == 0 ) {
                [nformat setMaximumFractionDigits:0];
            } else {                
                [nformat setMaximumFractionDigits:2];
            }

            stringValue = [NSString stringWithFormat: @"%@", [nformat stringFromNumber: [NSNumber numberWithDouble: doubleValue]] ];
            NSUInteger stringLen = [stringValue length];

            if ( [stringValue hasSuffix:@".00"] )
            {               
                // Remove suffix
                stringValue = [stringValue substringWithRange: NSMakeRange(0, stringLen-3)];            
            } else if ( [stringValue hasSuffix:@".0"] ) {

                // Remove suffix
                stringValue = [stringValue substringWithRange: NSMakeRange(0, stringLen-2)];

            } else if ( [stringValue hasSuffix:@"0"] ) {

                // Remove suffix
                stringValue = [stringValue substringWithRange: NSMakeRange(0, stringLen-1)];        
            }


            // Add the letter suffix at the end of it
            stringValue = [stringValue stringByAppendingString: s];

            //stringValue = [NSString stringWithFormat: @"%@%@", [nformat stringFromNumber: [NSNumber numberWithDouble: doubleValue]]  , s] ;
            break ;
        }   
    } 

    NSLog(@"Cash = %@", stringValue);