How To: Hash Data with Salt

Sample is here

Using PInvoke

Check out the PInvoke website. Greate Site for finding PInvoke syntax for c# Calls to the WIN 32 API.

A Winforms CheckList

• Check the StartPosition property is CenterParent
• Check the Text property (the Title) is set to something sensible
• IF it is a child window set the 'ShowInTaskbar' property to 'False'
• Check FormBorderStyle property is set to 'FixedDialog' on the Form if it is non-resizable.
• Check MaximiseBox property is set to 'True' on the Form if you want it
• Check MinimiseBox property is set to 'True' on the Form if you want it
• Check AcceptButton property is set on the Form to the 'default' accept/OK button
• Check CancelButton property is set on the Form to the 'default' cancel changes button
• IF you want the OK and cancel buttons to work automatically then set the DialogResult property of the button to Accept or Cancel etc.
• Check the TAB order is set.

OR put these in the xxxForm.designer.cs file, in InitializeComponent() just before ResumeLayout(false);

    this.AcceptButton = this.NAME_OF_ACCEPT_OK_BUTTON;
    this.CancelButton = this.NAME_OF_CANCEL_BUTTON;
    this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
    this.MaximizeBox = false;
    this.MinimizeBox = false;
    this.ShowIcon = false;
    this.ShowInTaskbar = false;
    this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
    this.Text = "FORM TITLE";

C# Lists And Arrays

C# Arrays Comprehensive
C# Lists

Modal/Modeless Dialogs

Modal Dialog

    SomeForm sf = new SomeForm();
    DialogResult res = sf.ShowDialog(this);

To close a form

... // within the form class itself
    DialogResult = DialogResult.OK;
    Close();
...

Set the AcceptButton and CancelButton to the correct buttons if required Modeless Dialog

    // Declare the modeless dialog
    private MagnifyingGlassForm m_MagFrm = null;


    // Creating and showing the modeless dialog
    if (m_MagFrm == null)
    {
      m_MagFrm = new MagnifyingGlassForm();
      m_MagFrm.Owner = this; // IMPORTANT Set the owner of the modeless dialog 
      m_MagFrm.Show(); // Show the modeless dialog
    }

    ...

    // To just hide the modeless dialog use Hide() method
    m_MagFrm.Hide()

    ...

    // Terminating the Modeless Dialog
    if (m_MagFrm != null)
    {
      m_MagFrm.Close();
      m_MagFrm.Dispose();
      m_MagFrm = null;
    }

Using DataTables, DataSets and DataAdaptors

Why use a Dataset? Using summary ADO.NET Tutorial

// Use Visual Studio to generate the data set classes. Use 'Typed' datasets
//XXXDataSet m_XXXDataSet = new XXXDataSet();
// Create the data table and data adaptors
XXXDataSet.XXXDataTable m_XXXDataTable;
XXXDataAdapter m_XXXDataAdaptor = new XXXDataAdapter();

// Filling the dataset/datatable
m_XXXDataTable = m_XXXDataAdaptor.GetData();
//m_DataAdaptor.Fill(m_XXXDataSet.XXX);


//Dont forget to Dispose()
//m_XXXDataSet.Dispose();
m_XXXDataTable.Dispose();
m_XXXDataAdaptor.Dispose();


// Finding a record
//XXXDataSet.XXXRow lir = m_XXXDataSet.XXX.FindByName(requestor.ToLower());
XXXDataSet.XXXRow lir = m_XXXDataTable.FindByName(requestor.ToLower());

// ADD
//m_XXXDataSet.XXX.AddXXXRow(userName, password);
m_XXXDataTable.AddXXXRow(userName, password);
m_Dirty = true;

// DELETE
//m_XXXDataSet.XXX.RemoveXXXRow(lir);
m_XXXDataTable.RemoveXXXRow(lir);
lir.Delete();

// UPDATING the database
m_DataAdaptor.Update(m_XXXDataTable);
//m_DataAdaptor.Update(m_XXXDataSet);

Double Buffering in C# .Net

Double Buffering in Dot Net 2.0
More Double Buffering in Dot Net 2.0 - Check this out as well

bool m_Dirty = true;
Bitmap m_Bitmap;

~XXXCtrl()
{
    Dispose(false);
}

public void ChangeSomething(int xmin, int xmax)
{
    ...
    Dirty = true; // Regenerate the bitmap (during the paint cycle)
    Invalidate(); // Repaint
}


protected override void OnResize(EventArgs e)
{
    _DisposeBitmap();
    if ((ClientSize.Width > 0) && (ClientSize.Height > 0))
    {
        m_Bitmap = new Bitmap(this.ClientSize.Width, this.ClientSize.Height);
    }
    else
    {
        m_Bitmap = null;
    }
    Dirty = true;
    base.OnResize(e);
    Invalidate();
}


protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
    Graphics gfx = e.Graphics;
    if (Dirty) 
    { // Only regenerate the bitmap when something has changed
        _RenderToBitmap();
        Dirty = false;
    }
    // Option 1:  Redraw entire bitmap
    //gfx.DrawRectangle(Pens.Red, e.ClipRectangle);
    //_DisplayBitmap(gfx, BitmapRect()); //
    // OR 
    // Option 2:  Redraw just the area that has changed           
    //Debug.WriteLine("Paint: e.ClipRectangle=" +
e.ClipRectangle.ToString());
    _DisplayBitmap(gfx, e.ClipRectangle); 
}


private void _DisplayBitmap(Graphics gfx, Rectangle clipRectangle)
{
    gfx.DrawImage(m_Bitmap, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
}

// Draw the graphics onto a bitmap
private void _RenderToBitmap()
{
    using (Graphics gs = Graphics.FromImage(m_Bitmap))
    {
      _Render(gs, BitmapRect());
    }
}

private Rectangle BitmapRect()
{
    return new Rectangle(0, 0, m_Bitmap.Width, m_Bitmap.Height);
}

// Here is the main graphics routine
private void _Render(Graphics ds, Rectangle area)
{
    // Draw rectangle around client rectangle and text in centre
    Rectangle rect = area;
    rect.Height -= 1;
    rect.Width -= 1;
    using (Brush brush = new SolidBrush(this.BackColor))
    {
        ds.FillRectangle(brush, rect);
    }
    ds.DrawRectangle(Pens.Black, rect);

    if ((area.Width > 25) && (area.Height > 10))
    {
        int xpos = 0;
        // Draw axis
        int x1 = area.Left + 20;
        int x2 = area.Right - 20;
        int ymid = (area.Height/2);
        ds.DrawLine(Pens.Black, new Point(x1, ymid), new Point(x2, ymid));

        ...        
    }
}

private bool Dirty
{
    get { return m_Dirty; }
    set { m_Dirty = value; }
}

private void _DisposeBitmap()
{
    if (m_Bitmap != null)
    {
        m_Bitmap.Dispose();
    }
}

and in the designer class

protected override void Dispose(bool disposing)
{
  if (disposing && (components != null))
  {
     components.Dispose();
  }

  _DisposeBitmap();

  base.Dispose(disposing);
}