Escape Quote in C# for javascript consumption

For .net 4.0 + there is standard HttpUtility.JavaScriptStringEncode

For earlier west wind solution described by Lone Coder is quite nice

Here is an efficient and robust method that I found at http://www.west-wind.com/weblog/posts/114530.aspx

/// <summary>
/// Encodes a string to be represented as a string literal. The format
/// is essentially a JSON string.
/// 
/// The string returned includes outer quotes 
/// Example Output: "Hello \"Rick\"!\r\nRock on"
/// </summary>
/// <param name="s"></param>
/// <returns></returns>
public static string EncodeJsString(string s)
{
    StringBuilder sb = new StringBuilder();
    sb.Append("\"");
    foreach (char c in s)
    {
        switch (c)
        {
            case '\"':
                sb.Append("\\\"");
                break;
            case '\\':
                sb.Append("\\\\");
                break;
            case '\b':
                sb.Append("\\b");
                break;
            case '\f':
                sb.Append("\\f");
                break;
            case '\n':
                sb.Append("\\n");
                break;
            case '\r':
                sb.Append("\\r");
                break;
            case '\t':
                sb.Append("\\t");
                break;
            default:
                int i = (int)c;
                if (i < 32 || i > 127)
                {
                    sb.AppendFormat("\\u{0:X04}", i);
                }
                else
                {
                    sb.Append(c);
                }
                break;
        }
    }
    sb.Append("\"");

    return sb.ToString();
}

I think you should rather look at the JavaScriptSerializer class. It's a lot more stable, and will correctly handle any kind of data or escape characters etc. Also, your code will look a lot cleaner.

In your case your class can look like this:

public static String dt2JSON(DataTable dt) {
    var rows = new List<Object>();
    foreach(DataRow row in dt.Rows)
    {
        var rowData = new Dictionary<string, object>();
        foreach(DataColumn col in dt.Columns)
            rowData[col.ColumnName] = row[col];
        rows.Add(rowData);
    }
    var js = new JavaScriptSerializer();
    return js.Serialize(new { rows = rows });
}

This method will return a correctly serialized json string... For example, sth like this:

{"rows":[{"id":1,"name":"hello"},{"id":2,"name":"bye"}]}

Have fun! :)