Question

我知道这应该是一个基本问题，但我正在打砖墙。我希望转到URL / URI下载生成的字符串，就好像我打开了一个文件，然后把它放到一个String变量中。

我一直在填写IO.Stream和Net.httpxxx，但还没有设法让元素以正确的方式排列。

我在打开标准流中的页面时得到“不支持给定路径的格式”，因为它不在本地文件系统中...我理解的那一点，我得不到的是......我如何实现平等：

Public Function GetWebPageAsString(pURL As String) As String
        Dim lStream As IO.StreamReader = New System.IO.StreamReader(pURL)
        Return lStream.ReadToEnd

End Function

Answer 1

简短的回答，在C＃中，看起来像

using(System.Net.WebClient client = new System.Net.WebClient())
{
  string html = client.DownloadString("http://www.google.com");
}

Answer 2

WebClient.OpenRead()可能就是你要找的东西。

上面链接的MSDN页面中的示例：

 Dim uriString as String
 uriString = "http://www.google.com"

 Dim myWebClient As New WebClient()

 Console.WriteLine("Accessing {0} ...", uriString)

 Dim myStream As Stream = myWebClient.OpenRead(uriString)

 Console.WriteLine(ControlChars.Cr + "Displaying Data :" + ControlChars.Cr)
 Dim sr As New StreamReader(myStream)
 Console.WriteLine(sr.ReadToEnd())

 myStream.Close()

Answer 3

此函数将任何URI下载到文件。您可以轻松地将其调整为将其放入字符串var：

public static int DownloadFile(String remoteFilename, String localFilename, bool enforceXmlSafe)
{
// Function will return the number of bytes processed
// to the caller. Initialize to 0 here.
int bytesProcessed = 0;

// Assign values to these objects here so that they can
// be referenced in the finally block
Stream remoteStream = null;
Stream localStream = null;
WebResponse response = null;            

// Use a try/catch/finally block as both the WebRequest and Stream
// classes throw exceptions upon error
try
{
    // Create a request for the specified remote file name
    WebRequest request = WebRequest.Create(remoteFilename);
    if (request != null)
    {
        // Send the request to the server and retrieve the
        // WebResponse object 
        response = request.GetResponse();
        if (response != null)
        {
            // Once the WebResponse object has been retrieved,
            // get the stream object associated with the response's data
            remoteStream = response.GetResponseStream();

            // Create the local file
            if (localFilename != null)
                localStream = File.Create(localFilename);
            else
                localStream = new MemoryStream();

            // Allocate a 1k buffer
            byte[] buffer = new byte[1024];
            int bytesRead;

            // Simple do/while loop to read from stream until
            // no bytes are returned
            do
            {
                // Read data (up to 1k) from the stream
                bytesRead = remoteStream.Read(buffer, 0, buffer.Length);

                // Write the data to the local file
                localStream.Write(buffer, 0, bytesRead);

                // Increment total bytes processed
                bytesProcessed += bytesRead;
            } while (bytesRead > 0);
        }
    }
}
catch (Exception e)
{
    Console.WriteLine(e.Message);
}
finally
{
    // Close the response and streams objects here 
    // to make sure they're closed even if an exception
    // is thrown at some point
    if (response != null) response.Close();
    if (remoteStream != null) remoteStream.Close();
    if (localStream != null) localStream.Close();
}

// Return total bytes processed to caller.
return bytesProcessed;
}

如何将网页下载到.NET中的流中

3 个答案: