如何使用序列表达式按需返回webstream中的行

这个函数很好,但它没有做我想做的事情,但我已经对它进行了优化,以确保对象的使用是正常的:

   let getStreamData_ok (uri:string) =
        let request = WebRequest.Create uri 
        use response = request.GetResponse()
        use stream = response.GetResponseStream()
        use reader = new StreamReader(stream)
        while not reader.EndOfStream do 
            ignore <| reader.ReadLine() 

我想连接到一个流,并按需一次将文件向下拉一行。此函数不起作用,我尝试过在序列表达式中来回移动不同的行,但没有成功:

let getStreamData_OnDemand (uri:string) =
    let request = WebRequest.Create uri 
    use response = request.GetResponse()

    seq { 
        use stream = response.GetResponseStream()
        use reader = new StreamReader(stream)
        while not reader.EndOfStream do 
            yield reader.ReadLine() 
    } 

使用代码:

let lines = getStreamData_OnDemand("http://stackoverflow.com/")
for line in lines do
    ignore line

谢谢你