Uri.EscapeDataString() - Invalid URI: The Uri string is too long

ETFairfax picture ETFairfax · Jul 14, 2011 · Viewed 18.9k times · Source

I'm using compact framework/C# on windows mobile.

In my application I am uploading data to the server by serializing objects and using a HttpWebRequest/POST request to send the information up. On the server the post data is de-serialised and saved to the db.

The other day I realised that I had a problem with special characters in the post data (ampersands etc..). So I introduced Uri.EscapeDataString() into the method and all was well.

However, today I have discovered that there is a problem when the application attempts to upload a large amount of data (I'm unsure of what exactly denotes "large" at the moment!)

Existing code (Kind of)

var uploadData = new List<Things>();

uploadData.Add(new Thing() { Name = "Test 01" });
uploadData.Add(new Thing() { Name = "Test 02" });
uploadData.Add(new Thing() { Name = "Test with an & Ampersand " }); // Do this a lot!!

var postData = "uploadData=" + Uri.EscapeDataString(JsonConvert.SerializeObject(uploadData, new IsoDateTimeConverter()));

Problem

The call to Uri.EscapeDataString() is causing the following exception:

System.UriFormatException: Invalid URI: The Uri string is too long.

Question

Are there any other ways to prepare the data for upload?

As far as I can see HttpUtility (which has its own Encode/Decode methods) is not available for the compact framework.

Answer

Alberto de Paola picture Alberto de Paola · May 25, 2012

Or you could simply split your string and call Uri.EscapeDataString(string) for each block, in order to avoid reimplementing the function.

Sample Code:

        String value = "large string to encode";
        int limit = 2000;

        StringBuilder sb = new StringBuilder();
        int loops = value.Length / limit;

        for (int i = 0; i <= loops; i++)
        {
            if (i < loops)
            {
                sb.Append(Uri.EscapeDataString(value.Substring(limit * i, limit)));
            }
            else
            {
                sb.Append(Uri.EscapeDataString(value.Substring(limit * i)));
            }
        }