ListView View Change

private void button2_Click(object sender, EventArgs e)
{
    int n = (int) listView1.View;
    if (n == 4)
        n = -1;
    listView1.View = (View)Enum.ToObject(typeof(View), ++n);
}

Gray Scale 2

using System.Drawing.Imaging;

public static Bitmap MakeGrayscale(Bitmap original)
{
    //create a blank bitmap the same size as original
    Bitmap newBitmap =
    new Bitmap(original.Width, original.Height);

    //get a graphics object from the new image
    Graphics g = Graphics.FromImage(newBitmap);

    //create the grayscale ColorMatrix
    ColorMatrix colorMatrix = new ColorMatrix(
    new float[][]{
        new float[] {.3f, .3f, .3f, 0, 0},
        new float[] {.59f, .59f, .59f, 0, 0},
        new float[] {.11f, .11f, .11f, 0, 0},
        new float[] {0, 0, 0, 1, 0},
        new float[] {0, 0, 0, 0, 1}});

    //create some image attributes
    ImageAttributes attributes = new ImageAttributes();

    //set the color matrix attribute
    attributes.SetColorMatrix(colorMatrix);

    //draw the original image on the new image
    //using the grayscale color matrix
    g.DrawImage(original,
    new Rectangle(0, 0, original.Width, original.Height),
    0, 0, original.Width, original.Height,
    GraphicsUnit.Pixel, attributes);

    //dispose the Graphics object
    g.Dispose();
    return newBitmap;
}

private void button1_Click(object sender, EventArgs e)
{
    Bitmap b = (Bitmap) pictureBox1.Image;
    pictureBox2.Image = MakeGrayscale(b);
}

Gray Scale

using System.Drawing.Imaging;

public Image GrayScaleImage(Graphics graph, Image img, int left, int top)
        {
                     
            ColorMatrix colorMix = new ColorMatrix();           
            colorMix.Matrix00 = 1 / 3f;
            colorMix.Matrix01 = 1 / 3f;
            colorMix.Matrix02 = 1 / 3f;
            colorMix.Matrix10 = 1 / 3f;
            colorMix.Matrix11 = 1 / 3f;
            colorMix.Matrix12 = 1 / 3f;
            colorMix.Matrix20 = 1 / 3f;
            colorMix.Matrix21 = 1 / 3f;
            colorMix.Matrix22 = 1 / 3f;

            ImageAttributes imgAttrib = new ImageAttributes();
            imgAttrib.SetColorMatrix(colorMix);

            graph.DrawImage(img, new Rectangle(left, top, img.Width,
                 img.Height), 0, 0, img.Width, img.Height,
                 GraphicsUnit.Pixel, imgAttrib);
            Bitmap bmp = new Bitmap(img);
            return bmp;

        }

Graphic Up

private void Form1_Paint(object sender, PaintEventArgs e)
{
    // حالت معمولی
    e.Graphics.DrawEllipse(new Pen(Color.Red, 10), 30, 30, 50, 50);

    //  SmoothingMode.AntiAlias  روانسازی به کمک
    e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
    e.Graphics.DrawEllipse(new Pen(Color.Blue, 10), 30, 100, 50, 50);
}

Get All Windows Handle

using System.Runtime.InteropServices;

// The signature for the callback method.
public delegate bool CallBack(IntPtr hwnd, int lParam);

[DllImport("user32.dll")]
public static extern int EnumWindows(CallBack callback, int param);
[DllImport("user32.dll")]
public static extern int GetWindowText(IntPtr hWnd,
    StringBuilder lpString, int nMaxCount);

static void Main(string[] args)
{
    // Request that the operating system enumerate all windows,
    // and trigger your callback with the handle of each one.
    EnumWindows(DisplayWindowInfo, 0);
    Console.ReadLine();
}

// The method that will receive the callback. The second
// parameter is not used, but is needed to match the
// callback's signature.
public static bool DisplayWindowInfo(IntPtr hWnd, int lParam)
{
    int chars = 100;
    StringBuilder buf = new StringBuilder(chars);
    if (GetWindowText(hWnd, buf, chars) != 0)
    {
        Console.WriteLine(buf);
    }
    return true;
}