无法从方法组转换为 System.Func<string>

Question

我正在尝试使用 .Net 4.0 任务 class 在后台使用线程下载 google 网页。问题是如果我的函数有 1 个或多个参数，应用程序将无法编译（不知道如何传递该参数）。所以我想知道如何在 DoWork() 方法中传递函数的参数。

这个有效：

    public Task<String> DoWork() {
        //create task, of which runs our work of a thread pool thread
        return Task.Factory.StartNew<String>(this.DownloadString);

    }


    private String DownloadString()
    {
        using (var wc = new WebClient())
            return wc.DownloadString("http://www.google.com");
    }

这不是：

    public Task<String> DoWork() {
        //create task, of which runs our work of a thread pool thread
        return Task.Factory.StartNew<String>(this.DownloadString);

    }


    private String DownloadString(String uri)
    {
        using (var wc = new WebClient())
            return wc.DownloadString(uri);
    }

错误是：

cannot convert from 'method group' to 'System.Func<string>'

提前致谢！

Answer 1

return Task.Factory.StartNew(() => this.DownloadString("http://...."));

Answer 2

return Task.Factory.StartNew(() => DownloadString("https://www.google.com"));

或

return Task.Factory.StartNew(() =>
            {
                using (var wc = new WebClient())
                    return wc.DownloadString("https://www.google.com");
            });

无法从方法组转换为 System.Func<string>

Cannot convert from method group to System.Func<string>

c#

wpf

.net-4.0

task-parallel-library