How to decode viewstate

Question

I need to see the contents of the viewstate of an asp.net page. I looked for a viewstate decoder, found Fridz Onion\'s ViewState Decoder but it asks for the url of a page to

Answer 1

Here is the source code for a ViewState visualizer from Scott Mitchell's article on ViewState (25 pages)

using System;
using System.Collections;
using System.Text;
using System.IO;
using System.Web.UI;


namespace ViewStateArticle.ExtendedPageClasses
{
    /// 

    /// Parses the view state, constructing a viaully-accessible object graph.
    /// 
    public class ViewStateParser
    {
        // private member variables
        private TextWriter tw;
        private string indentString = "   ";

        #region Constructor
        /// 

        /// Creates a new ViewStateParser instance, specifying the TextWriter to emit the output to.
        /// 
        public ViewStateParser(TextWriter writer)
        {
            tw = writer;
        }
        #endregion

        #region Methods
        #region ParseViewStateGraph Methods
        /// 

        /// Emits a readable version of the view state to the TextWriter passed into the object's constructor.
        /// 
        /// The view state object to start parsing at.
        public virtual void ParseViewStateGraph(object viewState)
        {
            ParseViewStateGraph(viewState, 0, string.Empty);    
        }

        /// 

        /// Emits a readable version of the view state to the TextWriter passed into the object's constructor.
        /// 
        /// A base-64 encoded representation of the view state to parse.
        public virtual void ParseViewStateGraph(string viewStateAsString)
        {
            // First, deserialize the string into a Triplet
            LosFormatter los = new LosFormatter();
            object viewState = los.Deserialize(viewStateAsString);

            ParseViewStateGraph(viewState, 0, string.Empty);    
        }

        /// 

        /// Recursively parses the view state.
        /// 
        /// The current view state node.
        /// The "depth" of the view state tree.
        /// A label to display in the emitted output next to the current node.
        protected virtual void ParseViewStateGraph(object node, int depth, string label)
        {
            tw.Write(System.Environment.NewLine);

            if (node == null)
            {
                tw.Write(String.Concat(Indent(depth), label, "NODE IS NULL"));
            } 
            else if (node is Triplet)
            {
                tw.Write(String.Concat(Indent(depth), label, "TRIPLET"));
                ParseViewStateGraph(((Triplet) node).First, depth+1, "First: ");
                ParseViewStateGraph(((Triplet) node).Second, depth+1, "Second: ");
                ParseViewStateGraph(((Triplet) node).Third, depth+1, "Third: ");
            }
            else if (node is Pair)
            {
                tw.Write(String.Concat(Indent(depth), label, "PAIR"));
                ParseViewStateGraph(((Pair) node).First, depth+1, "First: ");
                ParseViewStateGraph(((Pair) node).Second, depth+1, "Second: ");
            }
            else if (node is ArrayList)
            {
                tw.Write(String.Concat(Indent(depth), label, "ARRAYLIST"));

                // display array values
                for (int i = 0; i < ((ArrayList) node).Count; i++)
                    ParseViewStateGraph(((ArrayList) node)[i], depth+1, String.Format("({0}) ", i));
            }
            else if (node.GetType().IsArray)
            {
                tw.Write(String.Concat(Indent(depth), label, "ARRAY "));
                tw.Write(String.Concat("(", node.GetType().ToString(), ")"));
                IEnumerator e = ((Array) node).GetEnumerator();
                int count = 0;
                while (e.MoveNext())
                    ParseViewStateGraph(e.Current, depth+1, String.Format("({0}) ", count++));
            }
            else if (node.GetType().IsPrimitive || node is string)
            {
                tw.Write(String.Concat(Indent(depth), label));
                tw.Write(node.ToString() + " (" + node.GetType().ToString() + ")");
            }
            else
            {
                tw.Write(String.Concat(Indent(depth), label, "OTHER - "));
                tw.Write(node.GetType().ToString());
            }
        }
        #endregion

        /// 

        /// Returns a string containing the  property value a specified number of times.
        /// 
        /// The number of times to repeat the  property.
        /// A string containing the  property value a specified number of times.
        protected virtual string Indent(int depth)
        {
            StringBuilder sb = new StringBuilder(IndentString.Length * depth);
            for (int i = 0; i < depth; i++)
                sb.Append(IndentString);

            return sb.ToString();
        }
        #endregion

        #region Properties
        /// 

        /// Specifies the indentation to use for each level when displaying the object graph.
        /// 
        /// A string value; the default is three blank spaces.
        public string IndentString
        {
            get
            {
                return indentString;
            }
            set
            {
                indentString = value;
            }
        }
        #endregion
    }
}

And here's a simple page to read the viewstate from a textbox and graph it using the above code

private void btnParse_Click(object sender, System.EventArgs e)
        {
            // parse the viewState
            StringWriter writer = new StringWriter();
            ViewStateParser p = new ViewStateParser(writer);

            p.ParseViewStateGraph(txtViewState.Text);
            ltlViewState.Text = writer.ToString();
        }