列出Objective-C对象的选择器

这是基于运行时C函数的解决方案:

class_CopyMethodList返回给定类对象的类方法列表,该类对象可从对象获取。

#import <objc/runtime.h>

[…]

SomeClass * t = [[SomeClass alloc] init];

int i=0;
unsigned int mc = 0;
Method * mlist = class_copyMethodList(object_getClass(t), &mc);
NSLog(@"%d methods", mc);
for(i=0;i<mc;i++)
    NSLog(@"Method no #%d: %s", i, sel_getName(method_getName(mlist[i])));

/* note mlist needs to be freed */

我认为通常您希望在控制台中这样做,而不是将代码与调试代码混在一起。这是在LLDB中进行调试时可以做到的方法:

(假设对象t)

p int $num = 0;
expr Method *$m = (Method *)class_copyMethodList((Class)object_getClass(t), &$num);
expr for(int i=0;i<$num;i++) { (void)NSLog(@"%s",(char *)sel_getName((SEL)method_getName($m[i]))); }

这也可以通过SWIFT实现:

let obj = NSObject()

var mc: UInt32 = 0
let mcPointer = withUnsafeMutablePointer(&mc, { $0 })
let mlist = class_copyMethodList(object_getClass(obj), mcPointer)

print("\(mc) methods")

for i in 0...Int(mc) {
    print(String(format: "Method #%d: %s", arguments: [i, sel_getName(method_getName(mlist[i]))]))
}

输出:

251 methods
Method #0: hashValue
Method #1: postNotificationWithDescription:
Method #2: okToNotifyFromThisThread
Method #3: fromNotifySafeThreadPerformSelector:withObject:
Method #4: allowSafePerformSelector
Method #5: disallowSafePerformSelector
...
Method #247: isProxy
Method #248: isMemberOfClass:
Method #249: superclass
Method #250: isFault
Method #251: <null selector>

使用运行iOS 9.2、Xcode 7.2版(7C68)的6S模拟器进行测试。

像这样的东西应该管用(把它放在你好奇的物体里就行了)。例如,如果您有一个作为委托的对象,并且想要知道哪些“挂钩”可用,那么这将打印出消息来给您提供线索:

-(BOOL) respondsToSelector:(SEL)aSelector {
    printf("Selector: %s\n", [NSStringFromSelector(aSelector) UTF8String]);
    return [super respondsToSelector:aSelector];
}

注意,我在 iPhone开发者的食谱 所以我不能赊账!例如,我从 UIViewController 实现了协议 <UITableViewDelegate, UITableViewDataSource> :

Selector: tableView:numberOfRowsInSection:
Selector: tableView:cellForRowAtIndexPath:
Selector: numberOfSectionsInTableView:
Selector: tableView:titleForHeaderInSection:
Selector: tableView:titleForFooterInSection:
Selector: tableView:commitEditingStyle:forRowAtIndexPath:
Selector: sectionIndexTitlesForTableView:
Selector: tableView:sectionForSectionIndexTitle:atIndex:
...
...
etc.,etc.

灵感来自 JAL 答案是,你可以迅速做到:

extension NSObject {
    var __methods: [Selector] {
        var methodCount: UInt32 = 0
        guard
            let methodList = class_copyMethodList(type(of: self), &methodCount),
            methodCount != 0
        else { return [] }
        return (0 ..< Int(methodCount))
            .flatMap({ method_getName(methodList[$0]) })
    }
}