[ACCEPTED]-Get Size of Image File before downloading from web-.net

Accepted answer
Score: 23

Here is a simple example you can try if 3 you have files of different extensions like 2 .GIF, .JPG, etc you can create a variable 1 or wrap the code within a Switch Case Statement

System.Net.WebClient client = new System.Net.WebClient();
Int64 bytes_total= Convert.ToInt64(client.ResponseHeaders["Content-Length"])
MessageBox.Show(bytes_total.ToString() + " Bytes");
Score: 6

If the web-service gives you a Content-Length HTTP header 4 then it will be the image file size. However, if 3 the web-service wants to "stream" data 2 to you (using Chunk encoding), then you 1 won't know until the whole file is downloaded.

Score: 3

You can use this code:

using System.Net;

public long GetFileSize(string url)
    long result = 0;

    WebRequest req = WebRequest.Create(url);
    req.Method = "HEAD";
    using (WebResponse resp = req.GetResponse())
        if (long.TryParse(resp.Headers.Get("Content-Length"), out long contentLength))
            result = contentLength;

    return result;


Score: 2

You can use an HttpWebRequest to query the 2 HEAD Method of the file and check the Content-Length 1 in the response

Score: 0

You should look at this answer: C# Get http:/…/File Size where your 5 question is fully explained. It's using 4 HEAD HTTP request to retrieve the file size, but 3 you can also read "Content-Length" header 2 during GET request before reading response 1 stream.

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