c# - Task.Run 和 Task.Factory.StartNew 有什么区别

Question

我知道以前有人问过这个问题，但是在谷歌搜索之后我没有得到正确的答案。

我有这些代码行:

Task.Run(() => DoSomething())
    .ContinueWith(t=>Log.Error(t,"Error"), TaskContinuationOptions.OnlyOnFaulted);

Task.Factory.StartNew(() => DoSomething())
    .ContinueWith(t=>Log.Error(t,"Error"),TaskContinuationOptions.OnlyOnFaulted);

DoSomething 成功运行后，Task.Run 抛出 TaskCanceledException 而 Task.Factory.StartNew 工作美好的。为什么？

进一步阅读: Stephen Clearly on why not use Task.Factory.StartNew
MSDN Link

更新 2: 示例代码:

private async void button27_Click(object sender, EventArgs e)
{
    var r = new Random(System.DateTime.Now.Millisecond);

    await Task.Factory.StartNew(
        () => {
            Divide(r.Next(100), r.Next(-1, 10));
            Log.Information("Divide Done!");
        },
        CancellationToken.None,
        TaskCreationOptions.DenyChildAttach,
        TaskScheduler.Default)
    .ContinueWith(
        t => {
            Log.Error(t.Exception,"There is an exception on Divide");
        },
        TaskContinuationOptions.OnlyOnFaulted);
}

private static void Divide(int a, int b)
{
    var c = a/b;
}

Answer 1

Task.Run is actually implemented in terms of the same logic used for Task.Factory.StartNew, just passing in some default parameters. When you pass an Action to Task.Run:

Task.Run(someAction);

that’s exactly equivalent to:

Task.Factory.StartNew(someAction, 
    CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);

阅读更多 here .

如果你通过 CancellationToken.None , TaskCreationOptions.DenyChildAttach和 TaskScheduler.Default Task.Factory.StartNew 的参数参数你应该看到相同的结果。