C# 正在从任务获取返回值。运行
我有以下代码:C# 正在从任务获取返回值。运行,c#,.net,task-parallel-library,async-await,C#,.net,Task Parallel Library,Async Await,我有以下代码: public static async Task<string> Start(IProgress<ProcessTaskAsyncExProgress> progress) { const int total = 10; for (var i = 0; i <= total; i++) { await Task.Run(() => RunLongTask(i.ToString(CultureInfo.In
public static async Task<string> Start(IProgress<ProcessTaskAsyncExProgress> progress)
{
const int total = 10;
for (var i = 0; i <= total; i++)
{
await Task.Run(() => RunLongTask(i.ToString(CultureInfo.InvariantCulture)));
if (progress != null)
{
var args = new ProcessTaskAsyncExProgress
{
ProgressPercentage = (int)(i / (double)total * 100.0),
Text = "processing " + i
};
progress.Report(args);
}
}
return "Done";
}
private static string RunLongTask(string taskName)
{
Task.Delay(300);
return taskName + "Completed!";
}
但是我得到一个错误,说“字符串不可等待”。从末尾删除
结果。当您wait
时,您将从wait-able方法返回结果
var val = await Task.Run(() => RunLongTask(i.ToString(CultureInfo.InvariantCulture)));
这不是对老问题的直接回答,但对于正在搜索的其他人来说:
“正常情况下”您不应该这样做,但有时需要匹配库API,以便可以使用如下包装函数:
private async Task<string> WrapSomeMethod(string someParam)
{
//adding .ConfigureAwait(false) may NOT be what you want but google it.
return await Task.Run(() => SomeObj.SomeMethodAsync(someParam)).ConfigureAwait(false);
}
string blah = WrapSomeMethod(someParam).Result;
不建议使用.Result,@GabrielMorin是“正常”您不应该这样做,比如99%的时间。
string blah = WrapSomeMethod(someParam).Result;