Question

我有两个webclient方法一个接一个地执行。

问题是，第一个执行的只在第二个之后完成执行。

我的主要问题是，为了使第二种方法成功，第一种方法首先需要完成，因为第二种方法需要第一种方法的数据才能成功执行。

 {

string name;
string surname;
string url1 =" //sample/1";
string url2 ="//sample/2";

       //execution point!
        public void ListBox_SelectionChagned(Object sender, SelectionChangedEventArgs e)
        {
            var sel = ((ListBox)ContextMenuPopup.Child).SelectedItem;


            SubName = Convert.ToString(sel);


            try
            {

                WebClient webClient = new WebClient();
                Uri uri = new Uri(url1);
                webClient.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted1);
                webClient.OpenReadAsync(uri);


            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
  try
            {


                WebClient webClient = new WebClient();
                Uri uri = new Uri(url2 + name);
                webClient.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted2);
                webClient.OpenReadAsync(uri);
                System.Diagnostics.Debug.WriteLine(url2 + name);

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }



}

 //Method1       
void webClient_OpenReadCompleted1(object sender, OpenReadCompletedEventArgs e)
        {
            DataContractJsonSerializer ser = null;
            try
            {
                ser = new DataContractJsonSerializer(typeof(ObservableCollection<Subscriptions>));
                ObservableCollection<Subscriptions> alldata = ser.ReadObject(e.Result) as ObservableCollection<Subscriptions>;
                foreach (data _dt in alldata)
                {

                    name = First_Name;
                     surname = Surname;    
                    System.Diagnostics.Debug.WriteLine("My first name "  + name);


                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }

//Method2
        void webClient_OpenReadCompleted2(object sender, OpenReadCompletedEventArgs e)
        {
            DataContractJsonSerializer ser = null;
            try
            {
                ser = new DataContractJsonSerializer(typeof(ObservableCollection<Subscriptions>));
                ObservableCollection<Subscriptions> alldata = ser.ReadObject(e.Result) as ObservableCollection<Subscriptions>;
                foreach (data _dt in alldata)
                {

                    name = First_Name;
                     surname = Surname;    


                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }


 }
public class data 
    {


        public string First_Name { get; set; }
        public string Surname { get; set; }
    }
}

总结：我需要在第一个方法中获取值“name”并使用它在第二个方法中附加我的url2？

但我的第二种方法在我的第一种方法之前完成了吗？

Answer 1

然后将以下代码从selectionchanged事件处理程序移动到webClient_OpenReadCompleted1事件处理程序

WebClient webClient = new WebClient();
Uri uri = new Uri(url2 + name);
webClient.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted2);
webClient.OpenReadAsync(uri);
System.Diagnostics.Debug.WriteLine(url2 + name);

这意味着，您必须在成功完成第一个请求后发出第二个请求。

功能不按正确的步骤顺序执行

1 个答案: