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对于我的应用程序，我想将 NSString 转换为包含二进制等效项的 NSMutableString。所有空间都必须放在适当的位置。

我找到了一个将字符串转换为二进制的片段，但所有空格都被排除在外。它或多或少看起来像这样：

NSMutableString *str2 = [NSMutableString stringWithFormat:@""];
for(NSInteger numberCopy = str; numberCopy > 0; numberCopy >>=1) {
    //Prepend "0" or "1", depending on the bit
    [str2 insertString:((numberCopy & 1) ? @"1" : @"0") atIndex:0];
    }

输入str，输出str2。

对于包含空格的版本，我有一个数组将输入字符串除以componentsSeparatedByString: @" "，然后将二进制转换器片段（上图）除以每个数组对象。我将空格重新添加进去。

但是，我收到控制台错误

*** -[__NSArrayM objectAtIndex:]: index 2 beyond bounds [0 .. 1]

其次是（尽管我认为这并不重要）：

    0   CoreFoundation                      0x00007fff84a08b06 __exceptionPreprocess + 198
    1   libobjc.A.dylib                     0x00007fff8c72f3f0 objc_exception_throw + 43
    2   CoreFoundation                      0x00007fff849a58ec -[__NSArrayM objectAtIndex:] + 252
    3   G-Clock                             0x0000000100001ff1 -[GCAppController tick:] + 1937
    4   Foundation                          0x00007fff8a011d05 __NSFireDelayedPerform + 358
    5   CoreFoundation                      0x00007fff849c5804 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
    6   CoreFoundation                      0x00007fff849c531d __CFRunLoopDoTimer + 557
    7   CoreFoundation                      0x00007fff849aaad9 __CFRunLoopRun + 1529
    8   CoreFoundation                      0x00007fff849aa0e2 CFRunLoopRunSpecific + 290
    9   HIToolbox                           0x00007fff83bbdeb4 RunCurrentEventLoopInMode + 209
    10  HIToolbox                           0x00007fff83bbdb94 ReceiveNextEventCommon + 166
    11  HIToolbox                           0x00007fff83bbdae3 BlockUntilNextEventMatchingListInMode + 62
    12  AppKit                              0x00007fff88b7a533 _DPSNextEvent + 685
    13  AppKit                              0x00007fff88b79df2 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128
    14  AppKit                              0x00007fff88b711a3 -[NSApplication run] + 517
    15  AppKit                              0x00007fff88b15bd6 NSApplicationMain + 869
    16  G-Clock                             0x0000000100000ea2 main + 34
    17  libdyld.dylib                       0x00007fff864fc7e1 start + 0
    18  ???                                 0x0000000000000003 0x0 + 3
)

我不知道出了什么问题，更不用说如何改变它了。

我的代码，输入 str 和输出 str2：

//Convert to binary
        NSMutableString *str2 = [NSMutableString stringWithFormat:@""];
        int count = -1;
        NSArray *array = [str componentsSeparatedByString: @" "];
        NSUInteger numObjects = [array count];
        //Converts each object of array into binary separately, so spaces remain intact.
        while (1) {
            ++count;
            NSString *string = array[count];
            NSMutableString *mutStr = [NSMutableString stringWithFormat:@""];
            for (NSInteger numberCopy = [string intValue]; numberCopy > 0; numberCopy >>=1) {
                //Prepend "0" or "1", depending on the bit
                [mutStr insertString:((numberCopy & 1) ? @"1" : @"0") atIndex:0];
            }
            if (numObjects != count + 1) {
                //Add space if this is not last run through
                [mutStr appendString: @" "];
            } else break;
            [str2 appendString: mutStr];
        }
4

2 回答 2

1

您在循环中有两个count位置递增。在任何情况下也mutStr必须附加。str2

但我会改用 for 循环：

for (count = 0; count < numObjects; count++) {
    NSString *string = array[count];
    NSMutableString *mutStr = [NSMutableString stringWithFormat:@""];
    for (NSInteger numberCopy = [string intValue]; numberCopy > 0; numberCopy >>=1) {
        //Prepend "0" or "1", depending on the bit
        [mutStr insertString:((numberCopy & 1) ? @"1" : @"0") atIndex:0];
    }
    [str2 appendString: mutStr];
    if (numObjects != count + 1) {
        //Add space if this is not last run through
        [str2 appendString: @" "];
    }
}
于 2013-10-12T15:41:59.967 回答
0

这是一个逻辑错误。在@Martin 的部分之后，在最后一次运行中，else break在被调用的部分之后[array count]，并且由于在该计数索引处没有数组对象，因此程序中断了。

while (1) {
    ++count;
    if (count == numbObjects) 
       break;
    ...
    }
于 2013-10-12T15:58:09.120 回答