对web服务的异步请求
本文关键字:异步 请求 服务 web | 更新日期: 2023-09-27 18:03:45
如何从线程向web服务发出异步请求?
这是一个简短的答案,没有大量的解释。
在你的客户端对象上调用Async
方法之前,确保你没有在UI线程上运行:-
System.Threading.ThreadPool.QueueUserWorkItem( o =>
{
try
{
svc.SomeMethodAsync();
}
catch (err)
{
// do something sensible with err
}
});
现在相应的完成事件将发生在ThreadPool
线程上,而不是UI线程上。
这是一个使用WCF的解决方案。
服务代码FileService.svc
public class FileService
{
[OperationContract]
public byte[] GetFile(string filename)
{
byte[] File;
//do logic
return File;
}
}
客户机代码public int requested_file_count = 5;
public list<string> filenames;
public FileServiceClient svc
//Constructor
public Example()
{
svc = new FileServiceClient();
}
Public void GetFiles()
{
//Initialise the list of names and set the count of files received
filenames = new list<string>(5);
requested_file_count = filenames.Count;
svc.GetFileCompleted += new EventHandler<GetFileCompletedEventArgs>(GetFile_Completed);
//Call the Async Method passing it the file name and setting the userstate to 1;
svc.GetFileAsync(filenames[0],1);
}
void GetFile_Completed(object Sender, GetFileCompletedEventArgs e)
{
if (e.UserState == requested_file_count)
{
//All files have been downloaded
}
else
{
svc.GetFileAsync(filenames[e.UserState],++e.UserState);
}
//Do Something with the downloaded file
byte[] filedata = e.result;
}