How to Rotate a Picture in Winforms

How do I rotate a picture in WinForms

Here's a method you can use to rotate an image in C#:

/// <summary>
/// method to rotate an image either clockwise or counter-clockwise
/// </summary>
/// <param name="img">the image to be rotated</param>
/// <param name="rotationAngle">the angle (in degrees).
/// NOTE: 
/// Positive values will rotate clockwise
/// negative values will rotate counter-clockwise
/// </param>
/// <returns></returns>
public static Image RotateImage(Image img, float rotationAngle)
{
    //create an empty Bitmap image
    Bitmap bmp = new Bitmap(img.Width, img.Height);

    //turn the Bitmap into a Graphics object
    Graphics gfx = Graphics.FromImage(bmp);

    //now we set the rotation point to the center of our image
    gfx.TranslateTransform((float)bmp.Width / 2, (float)bmp.Height / 2);

    //now rotate the image
    gfx.RotateTransform(rotationAngle);

    gfx.TranslateTransform(-(float)bmp.Width / 2, -(float)bmp.Height / 2);

    //set the InterpolationMode to HighQualityBicubic so to ensure a high
    //quality image once it is transformed to the specified size
    gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;

    //now draw our new image onto the graphics object
    gfx.DrawImage(img, new Point(0, 0));

    //dispose of our Graphics object
    gfx.Dispose();

    //return the image
    return bmp;
}

How to rotate image in picture box

You'll have to use Timer to create rotation of the Image. There is no built in method exists for rotation.

Create a global timer:

Timer rotationTimer;

Initialize timer in the constructor of the form and create PictureBox MouseEnter and MouseLeave events:

//initializing timer
rotationTimer = new Timer();
rotationTimer.Interval = 150;    //you can change it to handle smoothness
rotationTimer.Tick += rotationTimer_Tick;

//create pictutrebox events
pictureBox1.MouseEnter += pictureBox1_MouseEnter;
pictureBox1.MouseLeave += pictureBox1_MouseLeave;

Then create their Event Handlers:

void rotationTimer_Tick(object sender, EventArgs e)
{
    Image flipImage = pictureBox1.Image;
    flipImage.RotateFlip(RotateFlipType.Rotate90FlipXY);
    pictureBox1.Image = flipImage;
}

private void pictureBox1_MouseEnter(object sender, EventArgs e)
{
    rotationTimer.Start();
}

private void pictureBox1_MouseLeave(object sender, EventArgs e)
{
    rotationTimer.Stop();
}

Is it possible to rotate a picture box without C# code on the Form Designer or change shape of picture box border?

You can use a WPF project to accomplish what you want. It is much more flexible than WinForms. Plus it supports true transparency. It does have a bit of a learning curve, but if you're just starting out, I think you would be better served to start with WPF.

You can rotate an Image (PictureBox) in WPF as follows:

<Window x:Class="WpfApplication.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Window1" Height="467" Width="616">
    <Grid>
        <Image Source="C:\MyFolder\MyImage.gif">
            <Image.LayoutTransform>
                <RotateTransform Angle="45" />
            </Image.LayoutTransform>
        </Image>
    </Grid>
</Window>

Images are rotated in PictureBox

Without the original image data, it's impossible to say for sure what going on. But it's clear that at some point, some software involved in the processing of the image has used the EXIF orientation property to rotate the image, rather than actually modifying the image data itself. This may be Photo Viewer or some other tool that handled the photo at some point.

Here is code you can use to detect the orientation of the image, as recorded in the EXIF data by the camera that took the picture:

static ImageOrientation GetOrientation(this Image image)
{
    PropertyItem pi = SafeGetPropertyItem(image, 0x112);

    if (pi == null || pi.Type != 3)
    {
        return ImageOrientation.Original;
    }

    return (ImageOrientation)BitConverter.ToInt16(pi.Value, 0);
}

// A file without the desired EXIF property record will throw ArgumentException.
static PropertyItem SafeGetPropertyItem(Image image, int propid)
{
    try
    {
        return image.GetPropertyItem(propid);
    }
    catch (ArgumentException)
    {
        return null;
    }
}

where:

/// <summary>
/// Possible EXIF orientation values describing clockwise
/// rotation of the captured image due to camera orientation.
/// </summary>
/// <remarks>Reverse/undo these transformations to display an image correctly</remarks>
public enum ImageOrientation
{
    /// <summary>
    /// Image is correctly oriented
    /// </summary>
    Original = 1,
    /// <summary>
    /// Image has been mirrored horizontally
    /// </summary>
    MirrorOriginal = 2,
    /// <summary>
    /// Image has been rotated 180 degrees
    /// </summary>
    Half = 3,
    /// <summary>
    /// Image has been mirrored horizontally and rotated 180 degrees
    /// </summary>
    MirrorHalf = 4,
    /// <summary>
    /// Image has been mirrored horizontally and rotated 270 degrees clockwise
    /// </summary>
    MirrorThreeQuarter = 5,
    /// <summary>
    /// Image has been rotated 270 degrees clockwise
    /// </summary>
    ThreeQuarter = 6,
    /// <summary>
    /// Image has been mirrored horizontally and rotated 90 degrees clockwise.
    /// </summary>
    MirrorOneQuarter = 7,
    /// <summary>
    /// Image has been rotated 90 degrees clockwise.
    /// </summary>
    OneQuarter = 8
}

The GetOrientation() method above is written as an extension method, but of course you can call it as a plain static method. Either way, just pass it the Bitmap object you've just opened from a file, and it will return the EXIF orientation stored in the file, if any.

With that in hand, you can rotate the image according to your needs.

c# winforms how to rotate an image (but not around its center)

Expanded Reply

There is no flicker whatsoever. The SetStyle in the ctor takes care of that. What you see as "flicker" is an artifact cause by three factors:

1. The update rate is only 10/sec. Try increasing that to 20 or 30.
2. The direction value is course. It should be based on time/accelleration. That is an exercise left to you.
3. The crappy "hand" image has hard, aliased edges. No matter how fast you update or how smooth you animate it, it's going to look jittery. Again, doing anti-aliased, blended graphics processing is left as an exercise.

Look at the code more carefully. This is not "painted on the form", it's a custom control. See how MetronomeControl derives from Control? See how we created the form by adding a MetronomeControl to it?

Picture boxes are for displaying static images, not for custom controls!

The way it updates is by creating a timer. When the timer's Tick event fires we update the angle and direction, more generally, we update the state of the control. The call to Invalidate tells the Operating System, "Hey, I need to be repainted, send me a WM_PAINT message when it's convenient!". Our OnPaint override simply paints the current state of the control.

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

class MetronomeControl : Control
{
    private Bitmap hand;
    private float angle = 0;
    private float direction = 2;
    private Timer timer = new Timer { Enabled = true, Interval = 30 };

    public MetronomeControl()
    {
        SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.UserPaint | ControlStyles.Opaque | ControlStyles.AllPaintingInWmPaint, true);
        hand = CreateCrappyHandBitmap();
        timer.Tick += new EventHandler(timer_Tick);
    }

    void timer_Tick(object sender, EventArgs e)
    {
        if (angle < -45 || angle > 45)
            direction = -direction;
        angle += direction;
        Invalidate();
    }

    private static Bitmap CreateCrappyHandBitmap()
    {
        Bitmap bitmap = new Bitmap(100, 300, PixelFormat.Format32bppArgb);
        using (Graphics graphics = Graphics.FromImage(bitmap))
        {
            graphics.Clear(Color.Transparent);
            graphics.FillRectangle(Brushes.LightGray, 50 - 5, 0, 10, 300);
            graphics.FillPolygon(Brushes.LightSlateGray, new Point[] { new Point(50 - 30, 40), new Point(50 + 30, 40), new Point(50 + 20, 80), new Point(50 - 20, 80) });
            graphics.FillEllipse(Brushes.LightSlateGray, 0, 200, 100, 100);
        }
        return bitmap;
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        // Erase background since we specified AllPaintingInWmPaint
        e.Graphics.Clear(Color.AliceBlue);

        e.Graphics.DrawString(Text, Font, Brushes.Black, new RectangleF(0, 0, ClientSize.Width, ClientSize.Height), new StringFormat { Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center });

        // Move the 0,0 point to the just below the bottom-center of our client area
        e.Graphics.TranslateTransform(ClientSize.Width / 2, ClientSize.Height + 40);
        // Rotate around this new 0,0
        e.Graphics.RotateTransform(angle);
        // Turn on AA to make it a bit less jagged looking
        e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        // Draw the image so that the center of the ellipse is at 0,0
        e.Graphics.DrawImage(hand, 0 - hand.Width / 2, 0 - hand.Height + 50);

        // Reset the transform for other drawing
        e.Graphics.ResetTransform();

        base.OnPaint(e);
    }
}

static class Program
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form
        {
            Text = "Metronome Control Demo",
            ClientSize = new Size(640, 480),
            Controls =
            {
                new MetronomeControl
                {
                    Location = new Point(10, 10),
                    Size = new Size (340, 300),
                    Font = new Font(FontFamily.GenericSansSerif, 24),
                    Text = "Metronome Control Demo",
                }
            }
        });
    }
}

How can I rotate an image by any degree?

I didn't understand what's your problem but I think that your code could be improved. I think that you don't need to use directly the Matrix class. There are some functions that does this work for you. Infact the only things you need are: set the point of the rotation as the center, rotate the graphics and draw on it, using some functions by the Graphics class.
So to rotate an image you can use this simple code:

private Bitmap RotateImage(Bitmap bmp, float angle) {
     Bitmap rotatedImage = new Bitmap(bmp.Width, bmp.Height);
     rotatedImage.SetResolution(bmp.HorizontalResolution, bmp.VerticalResolution);

     using (Graphics g = Graphics.FromImage(rotatedImage)) {
        // Set the rotation point to the center in the matrix
        g.TranslateTransform(bmp.Width / 2, bmp.Height / 2);
        // Rotate
        g.RotateTransform(angle);
        // Restore rotation point in the matrix
        g.TranslateTransform(- bmp.Width / 2, - bmp.Height / 2);
        // Draw the image on the bitmap
        g.DrawImage(bmp, new Point(0, 0));
     }

     return rotatedImage;
}

Spinning Image in Windows Forms (C#)

WinForms graphical API is very limited and thats why the whole platform is obsolete. WPF is more capable for graphical presentation because there is a hardware acceleration and DirectX behind that.
My opinion if you are creating entertaining solutions use at minimum WPF. If your aim is purely business then WinForms is more than enough.

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