执行选择器中的 EXC_BAD_INSTRUCTION [英] EXC_BAD_INSTRUCTION at performSelector

问题描述

我有这个代码:

dispatch_async(dispatch_get_main_queue(), ^(void){SEL 选择器 = @selector(callback:);[self.delegate performSelector:selector withObject:self];});

self.delegate 和 self 都不是 nil.

我在 performSelector 行收到 EXC_BAD_INSTRUCTION.

有什么想法吗?

解决方案

尝试直接使用选择器，并确保callback: 是 self.delegate 的有效方法:

dispatch_async(dispatch_get_main_queue(), ^(void){[self.delegate performSelector:@selector(callback:) withObject:self];});

<小时>

另一个调试技巧是设置NSZombieEnabled, MallocStackLogging 和 在调试器中保护 malloc.然后，当您的应用程序崩溃时，在 gdb 控制台中输入:

(gdb) info malloc-history 0x543216

将 0x543216 替换为导致崩溃的对象的地址，您将获得更有用的堆栈跟踪，它应该可以帮助您查明代码中导致问题的确切行.

查看这篇文章了解更多详细说明.>

I have this code:

dispatch_async(dispatch_get_main_queue(), ^(void) 
{ 
    SEL selector = @selector(callback:);
    [self.delegate performSelector:selector withObject:self];
});

Both self.delegate and self is not nil.

I am getting EXC_BAD_INSTRUCTION at the performSelector line.

Any idea?

解决方案

Try using the selector directly, and make surecallback: is a valid method of self.delegate:

dispatch_async(dispatch_get_main_queue(), ^(void) 
{ 
    [self.delegate performSelector:@selector(callback:) withObject:self];
});

---

Another debugging tip is to set NSZombieEnabled, MallocStackLogging, and guard malloc in the debugger. Then, when your App crashes, type this in the gdb console:

(gdb) info malloc-history 0x543216

Replace 0x543216 with the address of the object that caused the crash, and you will get a much more useful stack trace and it should help you pinpoint the exact line in your code that is causing the problem.

See this article for more detailed instructions.

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