如何将本机C类型与performSelectorOnMainThread:一起使用?

(void)setDoubleValue:(double)value performSelectorOnMainThread: .

我认为有效的方法是:

NSNumber *progress = [NSNumber numberWithDouble:50.0];
[progressIndicator performSelectorOnMainThread:@selector(setDoubleValue:)
                                    withObject:progress
                                 waitUntilDone:NO];

没用。

- (void)updateProgressIndicator:(NSNumber *)progress
{
    [progressIndicator setDoubleValue:[progress doubleValue]];
}

可以,但不是很干净。

NSInvocation .

NSInvocation *setDoubleInvocation;;
SEL selector = @selector(setDoubleValue:);
NSMethodSignature *signature;
signature = [progressIndicator methodSignatureForSelector:selector];
setDoubleInvocation = [NSInvocation invocationWithMethodSignature:signature];
[setDoubleInvocation setSelector:selector];
[setDoubleInvocation setTarget:progressIndicator];

double progress = 50.0;
[setDoubleInvocation setArgument:&progress atIndex:2];

[setDoubleInvocation performSelectorOnMainThread:@selector(invoke)
                                      withObject:nil
                                   waitUntilDone:NO];

这个解决方案是可行的,但它使用了大量代码,而且速度非常慢。(即使我存储了调用。)

还有别的办法吗?