需求：公司当前的项目有一个页面是需要两个请求并发，且都成功后才算整个界面的数据请求成功
思路：首先想到的就是用dispatch_group,可写好后dispatch_notify并未等请求的block都执行完后才走，后就定义了个bool属性，采用kvo的方式实现了，事后还是感觉不是很好，就又找了些资料，经实践dispatch_group的enter group和leave group可实现需求
关键代码如下
dispatch_group_t group = dispatch_group_create();
dispatch_queue_t queue =dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);
dispatch_group_enter(group);
dispatch_group_async(group, queue, ^{
//request
[self requestPropertiesWithParams:skuParams success:^() {
dispatch_group_leave(group);
} failed:^(NSString *errMsg) {
self.isFailed = YES;
dispatch_group_leave(group);
}];
});
dispatch_group_enter(group);
dispatch_group_async(group, queue, ^{
[self requetGoodsPropertiesDetailWithParams:skugoodsParams success:^() {
dispatch_group_leave(group);
} failed:^(NSString *errMsg) {
self.isFailed = YES;
dispatch_group_leave(group);
}];
});
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
if (self.isFailed == YES) {
if (self.requestFailedBlock) {
self.requestFailedBlock(@"请求失败");
}
}else{
[self filterData];
HLGoodsDetailModel *model = [self getNewModel:self.goodsDetailModel];
[self.itemsDict setObject:model forKey:fileName];
if (self.requestSuccessBlock) {
self.requestSuccessBlock(model);
}
}
});