Tag: .Net

Nothing advanced here, I just wanted to store this code snippet somewhere for easy reuse…

SqlConnection conn = new SqlConnection(@"...");
SqlCommand cmd = new SqlCommand("select * from employee", conn);
cmd.CommandType = CommandType.Text;

using (conn)
{
	conn.Open();
	SqlDataReader reader = cmd.ExecuteReader();
	while (reader.Read())
	{
		...
	}
}

This is an easy way of formatting an XmlDocument into an indented string. Could be useful for logging, etc?

XmlDocument doc = ...;
...
StringWriter sw = new StringWriter();
XmlTextWriter xtw = new XmlTextWriter(sw);
xtw.Formatting = Formatting.Indented;
doc.WriteTo(xtw);
Console.WriteLine(sw.ToString());

Function GetProcessText(ByVal process As String, ByVal param As String, _
        ByVal workingDir As String) As String
    Dim p As System.Diagnostics.Process = New System.Diagnostics.Process

    ' this is the name of the process we want to execute 
    p.StartInfo.FileName = process
    If Not (workingDir = "") Then
        p.StartInfo.WorkingDirectory = workingDir
    End If
    p.StartInfo.Arguments = param

    ' need to set this to false to redirect output
    p.StartInfo.UseShellExecute = False
    p.StartInfo.RedirectStandardOutput = True

    ' start the process 
    p.Start()

    ' read all the output
    ' here we could just read line by line and display it
    ' in an output window 
    Dim output As String = p.StandardOutput.ReadToEnd
    ' wait for the process to terminate 
    p.WaitForExit()
    Return output
End Function

Code from http://www.developerfusion.co.uk/show/4662/.

Question
How do I initialize the contents of a password textfield in ASP.NET 2.0?

Simple anwser
You can’t! This doesn’t work (apparently this is for security reasons, although the exact motivation escapes me):

txtPassword.Text = "this sucks";

Better answer
Create an event handler for the TextBox’s PreRender event:

protected void txtPassword_PreRender(object sender, EventArgs e)
{
    TextBox txt = (TextBox)sender;
    txt.Attributes["value"] = txt.Text;
}

Voilá! Now you can assign to the Text property as in the first example.

(Credits for this tip to David Silverlight.)

This is one way to retrieve the public key token for a strongly named .Net assembly:

sn -T C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Data.dll

Result:

Microsoft (R) .NET Framework Strong Name Utility  Version 2.0.50727.42
Copyright (c) Microsoft Corporation.  All rights reserved.

Public key token is b77a5c561934e089

Assuming that si is a SoapHttpClientProtocol instance, this is how set the credentials:

si.Credentials = CredentialCache.DefaultCredentials;

(If the client is a web application then impersonation must be enabled.)

or

NetworkCredential myCred = 
    new NetworkCredential(username, password, domainName); 
CredentialCache myCache = new CredentialCache(); 
myCache.Add(new Uri(si.Url), "NTLM", myCred); 
si.Credentials = myCache; 
si.UnsafeAuthenticatedConnectionSharing = true;
si.ConnectionGroupName = username;

Alternative 1 (type safe sorting using generics):

private int ComparePass(Pass x, Pass y)
{
    if (x.Starttid < y.Starttid) return -1;
    if (x.Starttid > y.Starttid) return 1;
    return 0;
}
:
:
    Pass[] results = ...;
    Array.Sort<Pass>(results, ComparePass);
:

Alternative 2 (type safe sorting using generics and an anonymous method):

Pass[] results = ...;
Array.Sort<Pass>(results,
    delegate(Pass x, Pass y)
    {
        if (x.Starttid < y.Starttid) return -1;
        if (x.Starttid > y.Starttid) return 1;
        return 0;
    });

Alternative 3 (type safe sorting using generics and an anonymous method using a default comparer):

Pass[] results = ...;
Array.Sort<Pass>(results, 
    delegate(Pass x, Pass y)
    {
        return Comparer.Default.Compare(x.Starttid, y.Starttid);
    });

Here’s how to draw an icon in a control utilizing the icon’s built-in alpha channel.

private void cmdEmail_Paint(object sender, 
  System.Windows.Forms.PaintEventArgs e)
{
  System.Drawing.Icon icon;
  icon = new Icon(
    GetType().Module.Assembly.GetManifestResourceStream(
      "ActiveSolution.Lernia.SFI.WinClient.Images.mail.ico"),
    16, 16); 
  e.Graphics.DrawIcon(icon,0,0);
}

The name of the icon resource is easily found using ildasm. Double-click on the “M A N I F E S T” node and look for the icon in the window that opens.

SoapHeaders can be used to send “extra” and optional parameters to web service methods and is a technique which can be extremely useful. See the following example:

Server-side (MyService.asmx):

public class MyService : System.Web.Services.WebService
{
   public class AddDateHeader : SoapHeader
   {
      public bool AddDate;
   }
   public AddDateHeader myheader;
   ...

   [WebMethod]
   [SoapHeader("myheader")]
   public string HelloWorld()
   {
      if (myheader != null && myheader.AddDate == true)
         return "Hello World " + DateTime.Now.ToString();
      else
         return "Hello World";
   }

Client-side:

localhost.MyService si = new localhost.MyService();
si.AddDateHeaderValue = new localhost.AddDateHeader();
si.AddDateHeaderValue.AddDate = true;
MessageBox.Show(si.HelloWorld());

Furthermore, these headers can be accessed in SoapExtension components. For example, there might be a SoapHeader that controls the transport of data.

Example:

Public Overrides Sub ProcessMessage(ByVal message As SoapMessage)
    Dim compress As Boolean = False
    Dim header As SoapHeader
    For Each header In message.Headers
        If header.GetType().Name = "Compress" Then
            compress = True
        End If
    Next
    ...

Sometimes it’s useful to have the header sent in both directions (both to and from the service). In this case, apply the attribute to the web method with the Direction attribute:

[SoapHeader("myheader", Direction = SoapHeaderDirection.InOut)]
public string HelloWorld()
{
    ...