如何将字符串从Objective-C传递给C函数并返回值?

也许是这样的

bool doSomethingToMyString(const char* originalString, char *buffer, unsigned int size)
{
    bool result = 0;
    if (size >= size_needed)
    {
        sprintf(buffer, "The new content for the string, maybe dependent on the originalString.");
        result = 1;
    }
    return result;
}

...
- (void) objectiveCFunctionOrSomething:(NSString *)originalString
{
    char myString[SIZE];
    if (doSomethingToMyString([originalString UTF8String], myString, SIZE))
    {
        NSString *myNSString = [NSString stringWithCString:myString encoding:NSUTF8StringEncoding];
        // alright!
    }
}

或者,你知道的,一些有这种效果的东西。

在中查看以下内容 NSString 文件:

– cStringUsingEncoding:
– getCString:maxLength:encoding:
– UTF8String
+ stringWithCString:encoding:

好吧,我开始工作了。这是我的C函数:

int testPassingChar(char buffer[]) {    
    strcpy(buffer, "ABCDEFGHIJ");
    return 0;
}

然后从Objective-C:

char test[10];
int i;
i = testPassingChar(test);
NSString* str = [[NSString alloc] initWithBytes:test length:sizeof(test) 
    encoding:NSASCIIStringEncoding];

为什么不把C函数包装成Objective-C呢?

-(NSString*)testPassingCharWithStringLength:(int)whateverLength {
     char *test = malloc(sizeof(char) * whateverLength);  
     //do whatever you need to *test here in C
     NSString *returnString = [NSString stringWithUTF8String:test];
     free(test);
     return returnString;
}

…例如。。。