消息推送：根据服务端推送过来的数据规则，跳转到对应的控制器

利用runtime动态生成对象、属性、方法这特性，我们可以先跟服务端商量好，定义跳转规则

• 推送过来的消息规则

// 这个规则肯定事先跟服务端沟通好，跳转对应的界面需要对应的参数
NSDictionary *userInfo = @{
                           @"class": @"TargetViewController",
                           @"property": @{
                                        @"ID": @"123",
                                        @"type": @"12"
                                   }
                           };

• 接收推送消息

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
{
    [self push:userInfo];
}

• 跳转页面

- (void)push:(NSDictionary *)params
{
    // 类名
    NSString *class =[NSString stringWithFormat:@"%@", params[@"class"]];
    const char *className = [class cStringUsingEncoding:NSASCIIStringEncoding];
    // 从一个字串返回一个类
    Class newClass = objc_getClass(className);
    if (!newClass)
    {
        // 创建一个类
        Class superClass = [NSObject class];
        newClass = objc_allocateClassPair(superClass, className, 0);
        // 注册你创建的这个类
        objc_registerClassPair(newClass);
    }
    // 创建对象
    id instance = [[newClass alloc] init];
    // 对该对象赋值属性
    NSDictionary * propertys = params[@"property"];
    [propertys enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        // 检测这个对象是否存在该属性
        if ([self checkIsExistPropertyWithInstance:instance verifyPropertyName:key]) {
            // 利用kvc赋值
            [instance setValue:obj forKey:key];
        }
    }];
    // 获取导航控制器
    UITabBarController *tabVC = (UITabBarController *)self.window.rootViewController;
    UINavigationController *pushClassStance = (UINavigationController *)tabVC.viewControllers[tabVC.selectedIndex];
    // 跳转到对应的控制器
    [pushClassStance pushViewController:instance animated:YES];
}

• 检测对象是否存在该属性

- (BOOL)checkIsExistPropertyWithInstance:(id)instance verifyPropertyName:(NSString *)verifyPropertyName
{
    unsigned int outCount, i;
    // 获取对象里的属性列表
    objc_property_t * properties = class_copyPropertyList([instance
                                                           class], &outCount);
    for (i = 0; i < outCount; i++) {
        objc_property_t property =properties[i];
        //  属性名转成字符串
        NSString *propertyName = [[NSString alloc] initWithCString:property_getName(property) encoding:NSUTF8StringEncoding];
        // 判断该属性是否存在
        if ([propertyName isEqualToString:verifyPropertyName]) {
            free(properties);
            return YES;
        }
    }
    free(properties);
    return NO;
}