我发现在代码下执行某些进程而没有冻结UI。按下“开始工作”按钮时执行此代码。我认为用户可以通过“停止”按钮停止这项工作。所以我在MSDN上发现了这篇文章。https://msdn.microsoft.com/en-us/library/jj155759.aspx。但是,在此代码中应用此CancellationToken
很难......任何人都可以帮助解决这个问题吗?
我只使用public static async Task<int> RunProcessAsync(string fileName, string args)
方法。
代码(来自https://stackoverflow.com/a/31492250):
public static async Task<int> RunProcessAsync(string fileName, string args)
{
using (var process = new Process
{
StartInfo =
{
FileName = fileName, Arguments = args,
UseShellExecute = false, CreateNoWindow = true,
RedirectStandardOutput = true, RedirectStandardError = true
},
EnableRaisingEvents = true
})
{
return await RunProcessAsync(process).ConfigureAwait(false);
}
}
// This method is used only for internal function call.
private static Task<int> RunProcessAsync(Process process)
{
var tcs = new TaskCompletionSource<int>();
process.Exited += (s, ea) => tcs.SetResult(process.ExitCode);
process.OutputDataReceived += (s, ea) => Console.WriteLine(ea.Data);
process.ErrorDataReceived += (s, ea) => Console.WriteLine("ERR: " + ea.Data);
bool started = process.Start();
if (!started)
{
//you may allow for the process to be re-used (started = false)
//but I'm not sure about the guarantees of the Exited event in such a case
throw new InvalidOperationException("Could not start process: " + process);
}
process.BeginOutputReadLine();
process.BeginErrorReadLine();
return tcs.Task;
}
用法:
var cancelToken = new CancellationTokenSource();
int returnCode = async RunProcessAsync("python.exe", "foo.py", cancelToken.Token);
if (cancelToken.IsCancellationRequested) { /* something */ }
单击开始按钮时,会启动一些python脚本。 当脚本运行并且用户想要停止它时,用户按下停止按钮。 然后程序在代码下执行。
cancelToken.Cancel();
非常感谢你阅读这个问题。
答案 0 :(得分:9)
简单的答案是,您可以在取消令牌时致电process.Kill()
:
cancellationToken.Register(() => process.Kill());
但这有两个问题:
InvalidOperationException
。Dispose()
从CancellationTokenRegistration
返回的Register()
,并且CancellationTokenSource
是长期存在的,那么您的内存会有泄漏,因为注册将会停留在内存中只要CancellationTokenSource
。根据您的要求和您对清洁代码的需求(即使以复杂性为代价),可以忽略问题#2并通过吞噬catch
中的异常来解决问题#1。 / p>
答案 1 :(得分:2)
现在很简单:
process.WaitForExitAsync(token);