Question

I have created a simple Custom View Application for Lion. Now a friend tested it using Snow Leopard and couldn t launch it. Sadly I don t have the Exception. The only thing I know is, that it s about the function-call of arc4random, which is not available in her version. I actually can t imagine, that such an essential function was introduced in Lion (yeah, im rather new to cocoa...), so do you guys have any idea, what that could be about? I ll try to get the Exception Details, but I am pretty much under time pressure...

Answer 1

我在Snow Leopard坠毁时,用坠毁报告说:

Dyld Error Message:
Symbol not found: _arc4random_buf
Referenced from: <myApp binary>
Expected in: /usr/lib/libSystem.B.dylib

我必须读到。在我认识到<代码>arc4random(>)自10.4起就可使用,但<代码>arc4random_buf(>仅自10.7起即可使用。如果你使用<代码>arc4random_buf(功能(如我)的话,则该编码将不使用10.6。

因此,我仅用以下C-code取代arc4random_buf()功能:

void myArc4RandBuf(uint8_t* randomBytes, size_t length) {
    size_t intBufLength = (length/4)+1;
    uint32_t randomInts[intBufLength];        
    for (int i = 0; i < intBufLength; i++) {
        randomInts[i] = arc4random();
    }
    memcpy(randomBytes, randomInts, length);
}

这可能较慢,因为<代码>arc4random(>)多次被点名,但每个宏观事务单位的工作从10.4人到10.8人。

友情链接