Search code examples
c#vb.netvisual-studiovisual-studio-2017debuggerdisplay

Cross language DataRow index in DebuggerDisplay


I am trying to customize debugged objects tooltips. To achieve this I have a library including Assembly: DebuggerDisplay attributes (Can the DebuggerDisplay attribute be applied to types one doesn't own?) in Visualizers folder (How to: Install a Visualizer).

I would like to see a DataRow index so I have in vb.net

<Assembly: DebuggerDisplay("Idx = {Table.Rows.IndexOf(Me)}", Target:=GetType(DataRow))> 

or in c#

[assembly: DebuggerDisplay(@"Idx = {Table.Rows.IndexOf(this)}", Target = typeof(DataRow))] 

The problem is that the expression is evaluated in debug time and the object self reference (Me x this) is different in both languages. So I am getting

CS0103  The name 'Me' does not exist in the current context

in the tooltip when I am debugging c# code.

Is there a way to get the index of DataRow with syntax common to both languages?


Solution

  • The source code of Rows.IndexOf

        public Int32 IndexOf(DataRow row) {
            if ((null == row) || (row.Table != this.table) || ((0 == row.RBTreeNodeId) && (row.RowState == DataRowState.Detached))) //Webdata 102857
                return -1;
            return list.IndexOf(row.RBTreeNodeId, row);
        }
    

    shows that it returns the result of list.IndexOf

        public int IndexOf (int nodeId, K item)
        {
            int index = -1;
            // BIG ASSUMPTION: There is not satellite tree, this is INDEX_ONLY.
            if (nodeId != NIL)
            {
                if ( (Object) Key(nodeId) == (Object)item) {
                    return GetIndexByNode(nodeId);
                }
                if ( (index=IndexOf(Left(nodeId), item)) != -1) {
                    return index;
                }
                if ( (index=IndexOf(Right(nodeId), item)) != -1) {
                    return index;
                }
            }
    
            return index;
        }
    

    If we assume that it is valid to call GetIndexByNode directly and pass the DataRow.RBTreeNodeId value directly, then the following should work.

    [assembly: DebuggerDisplay(@"Index = {Table.Rows.list.GetIndexByNode(RBTreeNodeId)}", Target = typeof(System.Data.DataRow))]