ios - 完成 block 完成后如何调用方法？

Question

我想先调用signUp方法，一旦我得到用户ID，我需要调用另一个方法normalSignupMethod。

[ConnectionObj signUp:user];
[helper normalSignupMethod:dict];

注册方法:

[MYRequest signUp:user successBlock:^(QBResponse *response, QBUUser *user) {
    // Sign up was successful
    // Store user id
    [SingletonClass sharedMySingleton].userID = [NSString stringWithFormat:@"%@",response.data[@"id"]];   

} errorBlock:^(QBResponse *response) {
    // Handle error here
    NSLog(@" error in creating session %@", response.error);
    [SVProgressHUD showErrorWithStatus:NSLocalizedString(@"SignUp to Chat error!", nil)];
}];

我是这样称呼的:

dispatch_group_t group = dispatch_group_create(); 
       dispatch_group_async(group,dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^ {
    NSLog(@"Block1");
    [ConnectionObj signUp:user];
});

dispatch_group_notify(group,dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^ {

    NSLog(@"Group notify");
    [helper normalSignupMethod:dict];
    dispatch_async(dispatch_get_main_queue(), ^{
        [SVProgressHUD dismiss];
    });
});

Block 1先执行，然后group notify被调用。但是在 normalSignupMethod 完成后我得到了 userID。如何在调用 normalSignupMethod 之前等待 signUp 方法获取用户 ID？

Answer 1

你可以像这样用你的 signUp 方法创建一个 block 并传递 Bool 完成值来检查它是否被成功调用。所以像这样更改您的方法声明。

-(void)signUp:(QBUser*)user andHandler:(void (^)(BOOL result))completionHandler;

及其定义

-(void)signUp:(QBUser*)user andHandler:(void (^)(BOOL result))completionHandler {
    [MYRequest signUp:user successBlock:^(QBResponse *response, QBUUser *user) {
        [SingletonClass sharedMySingleton].userID = [NSString stringWithFormat:@"%@",response.data[@"id"]];   
        completionHandler(YES);
    } errorBlock:^(QBResponse *response) {
       // Handle error here
        NSLog(@" error in creating session %@", response.error);
        [SVProgressHUD showErrorWithStatus:NSLocalizedString(@"SignUp to Chat error!", nil)];
        completionHandler(NO);
    }];
}

现在像这样调用这个方法。

[ConnectionObj signUp:user andHandler:^(BOOL result) {
    if(result) {
        [helper normalSignupMethod:dict];
    }
}];