Just a quick cheat sheet on converting to/from string to byte[] and back. I never remember exactly the syntax, so always spend a few minutes looking it up.

//Convert string to byte
byte[] bytes = System.Text.Encoding.Default.GetBytes("The string"); 

//Convert to Base64, view/save in config files, etc
string base64 = Convert.ToBase64String( bytes );

//Convert from Base64, back to string
bytes = Convert.FromBase64String( base64 );

//Convert byte to string
string msg = System.Text.Encoding.Default.GetString(bytes); 

//Create memory stream based on byte array
MemoryStream ms = new MemoryStream(bytes);
StreamReader sr = new StreamReader(ms); 

keywords: string byte convert base64 hex

(not exactly .NET related, but relevant to current times)

Now that I re-discovered xp_cmdshell, I'm paranoid about the security implications. The SQL install defaults to run the service as local system in the administrators group. Therefore, xp_cmdshell has all the privs of an administrator.

Here's an article that talks about the privileges needed if you change to a non-admin account for the service.

Apparently it is recommended to use SQL Enterprise Manager to make the "run as" change, so SQLEM will go through and add the right permissions to directories, registry keys, etc. If you do not use SQLEM (i.e. use control panel, services applet), then the article walks you through what else to change.

How to change the SQL Server or SQL Server Agent Service account without using SQL Enterprise Manager in SQL Server 2000

Microsoft "We Rock" ?? Not sure how good this is yet - got a link in MSDN flash newsletter, so it's semi-supported/recommended by MS.

Supposedly a DVD with audio, labs, etc. This one is on smart clients in .NET

Microsoft weRock247.NET Developer Roadmap

Slides and info from VS Live conference. Talks about what's coming in VS.NET 2005.

FTPOnline - VSLive! SF 2005 - Top 10 Visual C# 2005 IDE Enchancements

keywords: visual studio C# ide 2005 vsnet vs.net

I'm sure I'll need this someday if I ever get back into COM interop. Calling a COM method that has an outbound array using the size_is MIDL attribute.

The size_is keyword is lost when creating a type library, so the .NET marshaller cannot map the array length back into managed code. To get around this, you have to use IntPtr, then use the Marshal class to convert the returned buffer into array elements.

(Original article thanks to www.thinkdotnet.com which I think is dead now.)

keywords: com interop midl size_is array structs structures

typedef struct ASTRUCT

{

	[string] OLECHAR* str;

	long theLong;

};



[

	object,

	uuid(09db9b39-35c7-49e0-b7c4-a4bbdad4ea05),

	pointer_default(unique)

]

interface IStructTester : IUnknown

{

	HRESULT GetArrayOfStructs( [out] long* pCount, 

			[out,size_is(,*pCount)] AStruct** ppStructs );

}



[ StructLayout( LayoutKind.Sequential ) ]

public struct ASTRUCT

{

	[MarshalAs( UnmanagedType.LPWStr )]

	public String str;

	public long theLong;

}



[InterfaceType(ComInterfaceType.InterfaceIsIUnknown),

			Guid("09db9b39-35c7-49e0-b7c4-a4bbdad4ea05")]

{

	[PreserveSig(true)]

	void GetArrayOfStructs( out Int32 pCount, out IntPtr buffer );

}



	IntPtr	buffer;

	Int count = 0;

	

	IStructTester theInterface = (IStructTester)new StructTester();

	theInterface.GetArrayOfStructs( ref count, out buffer );

	

	// allocate the managed array

	ASTRUCT[] managedArray = new ASTRUCT[count];

	

	// now copy the array elements one-by-one, using the IntPtr buffer 

	for ( int i=0; i<count; i++ )

	{

		managedArray[i] = (ASTRUCT)Marshal.PtrToStructure( (int)buffer, 

						typeof(ASTRUCT) );

		buffer = (IntPtr)((long)buffer + Marshal.SizeOf(managedArray[0]));

	}

I know this is uber-easy stuff, but I'm always wishing I had a simple example of aspx page with all the code (html markup + c# code) all in the same page.

This is from MS QuickStart tutorials, ASP.NET DataGrid with template columns, ItemCommand event handling, etc. Code is in a server-side script tag (runat = server).

QuickStarts Source Control Viewer

Page in action here

Question for a guru somewhere: how does the Page_Load() method get called? Usually in the IDE supported code-behind page, in InitializeComponent(), the Page.Load event is wired up to Page_Load(). Here in an aspx page only, who calls Page_Load()??

There's a lot to show on this single blog entry, but here is the code in case they move/bail the page someday.

<% @Import Namespace="System.Data" %>



<html>



<script language="c#" runat="server">



    DataTable Cart;

    DataView CartView;

    

	ICollection CreateDataSource() 

	{

        DataTable dt = new DataTable();

        DataRow dr;



        dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));

        dt.Columns.Add(new DataColumn("StringValue", typeof(string)));

        dt.Columns.Add(new DataColumn("DateTimeValue", typeof(DateTime)));

        dt.Columns.Add(new DataColumn("BoolValue", typeof(bool)));

        dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));

        

		for ( int i = 0; i<9; i++) {

            dr = dt.NewRow();

            dr[0] = i;

            dr[1] = "Item " + i.ToString();

            dr[2] = DateTime.Now;

            dr[3] = (i % 2 != 0) ? true : false;

            dr[4] = 1.23 * (i+1);

            dt.Rows.Add(dr);

            

        }

        

		DataView dv = new DataView(dt); 

		return dv;       

	}



	void Page_Load( Object sender, EventArgs e )

	{

        if (Session["DG5_ShoppingCart"] == null) {

            Cart = new DataTable();

            Cart.Columns.Add(new DataColumn("Item", typeof(string)));

            Cart.Columns.Add(new DataColumn("Price", typeof(string)));

            Session["DG5_ShoppingCart"] = Cart;

        }

        else {

            Cart = (DataTable)Session["DG5_ShoppingCart"];

        }    

        CartView = new DataView(Cart);

        ShoppingCart.DataSource = CartView;

        CartView.Sort="Item";

        ShoppingCart.DataBind();	

        

		MyDataGrid.DataSource = CreateDataSource(); 

		MyDataGrid.DataBind();

	}

	

    void Grid_CartCommand(object sender, DataGridCommandEventArgs e) {

    

        DataRow dr = Cart.NewRow();

        

        // e.Item is the row of the table where the command fired

        // For bound columns the value is stored in the Text property of TableCell

        TableCell itemCell = e.Item.Cells[1];

        TableCell priceCell = e.Item.Cells[2];

        string item = itemCell.Text;

        string price = priceCell.Text;

        

        if (((LinkButton)e.CommandSource).CommandName == "AddToCart") {

            dr[0] = item;

            dr[1] = price;

            Cart.Rows.Add(dr);

        }

        else {   //Remove from Cart

        

            CartView.RowFilter = "Item='"+item+"'";

            if (CartView.Count > 0) {    

                CartView.Delete(0);

            }

            CartView.RowFilter = "";

        }

        ShoppingCart.DataBind();

    }	

	

</script>



	

	

<body>



    <h3><font face="Verdana">Using a Template Column in DataGrid</font></h3>



    <form runat=server>



    <table cellpadding="5">

    <tr valign="top">

    <td>



    <b>Product List</b>

    <asp:DataGrid id="MyDataGrid" runat="server"

        BorderColor="black"

        BorderWidth="1"

        GridLines="Both"

        CellPadding="3"

        CellSpacing="0"

        Font-Name="Verdana"

        Font-Size="8pt"

        HeaderStyle-BackColor="#aaaadd"

        AutoGenerateColumns="false"

        OnItemCommand="Grid_CartCommand"

        >

        <Columns>

            <asp:TemplateColumn HeaderText="Add/Remove">

                <ItemTemplate>

                    <asp:LinkButton ID=AddButton Text="Add" CommandName="AddToCart" 

							ForeColor="blue" runat="server" /> 

                    <asp:LinkButton ID=RemoveButton Text="Remove" CommandName="RemoveFromCart" 

							ForeColor="blue" runat="server" />

                </ItemTemplate>

            </asp:TemplateColumn>

            

            <asp:BoundColumn HeaderText="Item" DataField="StringValue"/>

            <asp:BoundColumn HeaderText="Price" DataField="CurrencyValue" 

					DataFormatString="{0:c}" ItemStyle-HorizontalAlign="right" />

            

            <asp:TemplateColumn HeaderText="Assembly required?">

                <ItemTemplate>

                    <asp:CheckBox ID=Chk1 

                    Checked='<%# DataBinder.Eval(Container.DataItem, "BoolValue") %>' 

                    Enabled="false" runat="server" />

                </ItemTemplate>

            </asp:TemplateColumn>

        </Columns>

    </asp:DataGrid>



    </td><td>



    <b>Shopping Cart</b>

    <asp:DataGrid id="ShoppingCart" runat="server"

        BorderColor="black"

        BorderWidth="1"

        CellPadding="3"

        Font-Name="Verdana"

        Font-Size="8pt"

        HeaderStyle-BackColor="#aaaadd"

        />



    </td>

    </tr>

    </table>



  </form>



</body>



</html>