0

就像标题说的：我有一个 ObjcClass 我想要一些东西可以被重用，因为这个类可能有 -(void)test1:xxx -(void)test2:xxx argu:yyy 我不想那样做

[dispatchArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
      [obj test2:xxx argu:yyy];
 }];

例子：

 - (void)test:(NSString *)argument1 {
    NSArray *dispatchArray = @[];//If the array is initialized with multiple objects
//I want each object to call the "test:" method unlike the following
//    [dispatchArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
//        [obj performSelector:@selector(test:) withObject:argument1];
//        // or [obj test:argument1];
//    }];
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [_services enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL * stop) {
        if ([obj respondsToSelector:_cmd]) {
            [obj application:application didFinishLaunchingWithOptions:launchOptions];
        }
    }];

    return YES;
}

像这样，UIApplicationDelegate 有很多方法，我不想写 [obj application:application didFinishLaunchingWithOptions:launchOptions]; 或[obj applicationWillResignActive:application]; 在每个方法中，相反我希望像[obj respondsToSelector:_cmd]这样的方法，我可以提出像[obj invokeWithMethod:_cmd arguments:_VA_LIST] 这样的通用方法； 这些方法是否可以优化，因为它们对不同的方法做同样的事情

4

2 回答 2

1

您应用程序委托的方法已经实现，您应该像以前一样实现。UIApplicationDelegate对于您的应用委托未实现的协议中的方法，您可以使用消息转发来实现您的目标。覆盖您的应用程序委托的消息转发方法，如下所示：

- (BOOL)respondsToSelector:(SEL)aSelector {
    struct objc_method_description desc = protocol_getMethodDescription(objc_getProtocol("UIApplicationDelegate"), aSelector, NO, YES);
    if (desc.name != nil) {
        return YES;
    }
    return [super respondsToSelector:aSelector];
}

- (void)forwardInvocation:(NSInvocation *)anInvocation {
    SEL selector = [anInvocation selector];
    struct objc_method_description desc = protocol_getMethodDescription(objc_getProtocol("UIApplicationDelegate"), selector, NO, YES);
    if (desc.name != nil) {
        [_services enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
            if ([obj respondsToSelector:selector]) {
                [anInvocation invokeWithTarget:obj];
            }
        }];
    }
}

获取返回值：

NSMutableArray *returnValues = [NSMutableArray array];
[_services enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
    id returnValue = [NSNull null];
    if ([obj respondsToSelector:selector]) {
        [anInvocation invokeWithTarget:obj];

        const char *returnType = anInvocation.methodSignature.methodReturnType;

        if( !strcmp(returnType, @encode(void)) ){
            //If the return value is `void`, just set returnValue = [NSNull null]
        } else if( !strcmp(returnType, @encode(id)) ){
            // if the return type is derived data types(`id`)
            [anInvocation getReturnValue:&returnValue];
        }else{
            //if the return value is basicdata type
            NSUInteger length = [anInvocation.methodSignature methodReturnLength];
            void *buffer = (void *)malloc(length);
            [anInvocation getReturnValue:buffer];
            if( !strcmp(returnType, @encode(BOOL)) ) {
                returnValue = [NSNumber numberWithBool:*((BOOL*)buffer)];  
            } else if( !strcmp(returnType, @encode(NSInteger)) ){
                returnValue = [NSNumber numberWithInteger:*((NSInteger*)buffer)];  
            }  
            returnValue = [NSValue valueWithBytes:buffer objCType:returnType];
        }
    }
    // If the `obj` can not responds to selector, or the return value is void(nil), we set the `returnValue = [NSNull null]`
    [returnValues addObject:returnValue];
}]
于 2016-07-29T03:53:09.793 回答
0

看起来您只想遍历数组中的对象。这不是很安全的类型。所有对象都必须提供“测试”方法。如果它们都是同一个类，那会比使用 NSObject 更好。

for (NSObject *obj in dispatchArray) {
        [obj performSelector:@selector(test:) withObject:argument1];
}
于 2016-07-29T03:31:26.760 回答