How do I rotate a picture in WinForms

Question

I want to have one picture in my application that I can rotate to indicate directions  like wind direction  Or even the time  What code do I use to rotate the picture  Thanks  Update  I am using  NET 2 0  Windows 2000  VS C  2005

User · Answer

This solution assumes that you want to draw the image in a picture box and that the image orientation will follow the mouse movements over this picture box. No image is assigned to the picture box. Instead I'm getting the image from a project resource.

private float _angle;

public Form1()
{
    InitializeComponent();
}

private void PictureBox_MouseMove(object sender, MouseEventArgs e)
{
    (float centerX, float centerY) = GetCenter(pictureBox1.ClientRectangle);
    _angle = (float)(Math.Atan2(e.Y - centerY, e.X - centerX) * 180.0 / Math.PI);
    pictureBox1.Invalidate(); // Triggers redrawing
}

private void PictureBox_Paint(object sender, PaintEventArgs e)
{
    Bitmap image = Properties.Resources.ExampleImage;
    float scale = (float)pictureBox1.Width / image.Width;

    (float centerX, float centerY) = GetCenter(e.ClipRectangle);

    e.Graphics.TranslateTransform(centerX, centerY);
    e.Graphics.RotateTransform(_angle);
    e.Graphics.TranslateTransform(-centerX, -centerY);
    e.Graphics.ScaleTransform(scale, scale);
    e.Graphics.DrawImage(image, 0, 0);
}

// Uses C# 7.0 value tuples / .NET Framework 4.7.
// For previous versions, return a PointF instead.
private static (float, float) GetCenter(Rectangle rect)
{
    float centerX = (rect.Left + rect.Right) * 0.5f;
    float centerY = (rect.Top + rect.Bottom) * 0.5f;
    return (centerX, centerY);
}

Make sure to to select the mouse event handlers PictureBox_MouseMove and PictureBox_Paint in properties window of the picture box for these events, after you copy/pasted this code into the form.

Note: You could also use a simple Panel or any other control, like a label; however, the PictureBox has the advantage to use double buffering by default, which eliminates flickering.

User · Answer

I have modified the function of  Mr net prog  which gets only the picture box and rotate the image in it       public static void RotateImage PictureBox picBox                 Image img   picBox Image          var bmp   new Bitmap img            using  Graphics gfx   Graphics FromImage bmp                         gfx Clear Color White               gfx DrawImage img  0  0  img Width  img Height                      bmp RotateFlip RotateFlipType Rotate270FlipNone           picBox Image   bmp

User · Answer

You can easily do it by calling this method    public static Bitmap RotateImage Image image  float angle        if  image    null          throw new ArgumentNullException  image         PointF offset   new PointF  float image Width   2   float image Height   2          create a new empty bitmap to hold rotated image     Bitmap rotatedBmp   new Bitmap image Width  image Height       rotatedBmp SetResolution image HorizontalResolution  image VerticalResolution          make a graphics object from the empty bitmap     Graphics g   Graphics FromImage rotatedBmp          Put the rotation point in the center of the image     g TranslateTransform offset X  offset Y          rotate the image     g RotateTransform angle          move the image back     g TranslateTransform -offset X  -offset Y          draw passed in image onto graphics object     g DrawImage image  new PointF 0  0         return rotatedBmp      don t forget to add a reference to System Drawing dll on your project   Example of this method call    Image image   new Bitmap  waves png    Image newImage   RotateImage image  360   newImage Save  newWaves png

User · Answer

Rotating image is one thing  proper image boundaries in another  Here is a code which can help anyone  I created this based on some search on internet long ago            lt summary gt          Rotates image in radian angle          lt  summary gt           lt param name  bmpSrc  gt  lt  param gt           lt param name  theta  gt in radian lt  param gt           lt param name  extendedBitmapBackground  gt Because of rotation returned bitmap can have different boundaries from original bitmap  This color is used for filling extra space in bitmap lt  param gt           lt returns gt  lt  returns gt      public static Bitmap RotateImage Bitmap bmpSrc  double theta  Color  extendedBitmapBackground   null                theta   Convert ToSingle theta   180   Math PI           Matrix mRotate   new Matrix            mRotate Translate bmpSrc Width   -2  bmpSrc Height   -2  MatrixOrder Append           mRotate RotateAt  float theta  new Point 0  0   MatrixOrder Append           using  GraphicsPath gp   new GraphicsPath                  transform image points by rotation matrix             gp AddPolygon new Point     new Point 0  0   new Point bmpSrc Width  0   new Point 0  bmpSrc Height                  gp Transform mRotate               PointF   pts   gp PathPoints                  create destination bitmap sized to contain rotated source image             Rectangle bbox   BoundingBox bmpSrc  mRotate               Bitmap bmpDest   new Bitmap bbox Width  bbox Height                using  Graphics gDest   Graphics FromImage bmpDest                                 if  extendedBitmapBackground    null                                        gDest Clear extendedBitmapBackground Value                                        draw source into dest                 Matrix mDest   new Matrix                    mDest Translate bmpDest Width   2  bmpDest Height   2  MatrixOrder Append                   gDest Transform   mDest                  gDest DrawImage bmpSrc  pts                   return bmpDest                                      private static Rectangle BoundingBox Image img  Matrix matrix                GraphicsUnit gu   new GraphicsUnit            Rectangle rImg   Rectangle Round img GetBounds ref gu                Transform the four points of the image  to get the resized bounding box          Point topLeft   new Point rImg Left  rImg Top           Point topRight   new Point rImg Right  rImg Top           Point bottomRight   new Point rImg Right  rImg Bottom           Point bottomLeft   new Point rImg Left  rImg Bottom           Point   points   new Point     topLeft  topRight  bottomRight  bottomLeft            GraphicsPath gp   new GraphicsPath points  new byte      byte PathPointType Start   byte PathPointType Line   byte PathPointType Line   byte PathPointType Line             gp Transform matrix           return Rectangle Round gp GetBounds

User · Answer

Here s a method you can use to rotate an image in C         lt summary gt      method to rotate an image either clockwise or counter-clockwise      lt  summary gt       lt param name  img  gt the image to be rotated lt  param gt       lt param name  rotationAngle  gt the angle  in degrees       NOTE       Positive values will rotate clockwise     negative values will rotate counter-clockwise      lt  param gt       lt returns gt  lt  returns gt  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

User · Answer

I found this article         lt summary gt          Creates a new Image containing the same image only rotated          lt  summary gt           lt param name   image   gt The  lt see cref   System Drawing Image    gt  to rotate          lt param name   offset   gt The position to rotate from           lt param name   angle   gt The amount to rotate the image  clockwise  in degrees          lt returns gt A new  lt see cref   System Drawing Bitmap    gt  of the same size rotated  lt  see gt           lt exception cref   System ArgumentNullException   gt Thrown if  lt see cref   image    gt           is null  lt  see gt      public static Bitmap RotateImage Image image  PointF offset  float angle                if  image    null              throw new ArgumentNullException  image               create a new empty bitmap to hold rotated image         Bitmap rotatedBmp   new Bitmap image Width  image Height           rotatedBmp SetResolution image HorizontalResolution  image VerticalResolution              make a graphics object from the empty bitmap         Graphics g   Graphics FromImage rotatedBmp              Put the rotation point in the center of the image         g TranslateTransform offset X  offset Y              rotate the image         g RotateTransform angle              move the image back         g TranslateTransform -offset X  -offset Y              draw passed in image onto graphics object         g DrawImage image  new PointF 0  0             return rotatedBmp

User · Answer

Richard Cox has a good solution to this https   stackoverflow com a 5200280 1171321 I have used in the past   It is also worth noting the DPI must be 96 for this to work correctly   Several of the solutions on this page do not work at all

User · Answer

This will work as long as the image you want to rotate is already in your Properties resources folder    In Partial Class   Bitmap bmp2    OnLoad    bmp2   new Bitmap Tycoon Properties Resources save2               pictureBox6 SizeMode   PictureBoxSizeMode StretchImage              pictureBox6 Image   bmp2    Button or Onclick   private void pictureBox6 Click object sender  EventArgs e                        if  bmp2    null                                bmp2 RotateFlip RotateFlipType Rotate90FlipNone                   pictureBox6 Image   bmp2

User · Answer

Old question but I had to address MrFox s comment in the accepted answer  Rotating an image when the size changes cuts off the edges of the image  One solution is to redraw the original on a larger image  centered  where the larger image s dimensions compensate for the need of not clipping the edges  For example  I wanted to be able to design a game s tiles at a normal angle but re-draw them at a 45-degree angle for an isometric view   Here are example images  yellow borders are to make it easier to see here    The original image    The centered tile in a larger image    The rotated image  where you rotate the larger image  not the original     The code  based in part on this answer in another question    private Bitmap RotateImage Bitmap rotateMe  float angle          First  re-center the image in a larger image that has a margin frame       to compensate for the rotated image s increased size      var bmp   new Bitmap rotateMe Width    rotateMe Width   2   rotateMe Height    rotateMe Height   2         using  Graphics g   Graphics FromImage bmp           g DrawImageUnscaled rotateMe   rotateMe Width   4    rotateMe Height   4   bmp Width  bmp Height        bmp Save  moved png        rotateMe   bmp         Now  actually rotate the image     Bitmap rotatedImage   new Bitmap rotateMe Width  rotateMe Height        using  Graphics g   Graphics FromImage rotatedImage                 g TranslateTransform rotateMe Width   2  rotateMe Height   2       set the rotation point as the center into the matrix         g RotateTransform angle                                            rotate         g TranslateTransform -rotateMe Width   2  -rotateMe Height   2     restore rotation point into the matrix         g DrawImage rotateMe  new Point 0  0                               draw the image on the new bitmap            rotatedImage Save  rotated png        return rotatedImage

User · Answer

I ve written a simple class for rotating image  All you ve to do is input image and angle of rotation in Degree  Angle must be between -90 and  90   public class ImageRotator       private readonly Bitmap image      public Image OriginalImage               get   return image                private ImageRotator Bitmap image                this image   image              private double GetRadian double degree                return degree   Math PI    double 180              private Size CalculateSize double angle                double radAngle   GetRadian angle           int width    int  image Width   Math Cos radAngle    image Height   Math Sin radAngle            int height    int  image Height   Math Cos radAngle    image Width   Math Sin radAngle            return new Size width  height              private PointF GetTopCoordinate double radAngle                Bitmap image   CurrentlyViewedMappedImage BitmapImage          double topX   0          double topY   0           if  radAngle  gt  0                        topX   image Height   Math Sin radAngle                     if  radAngle  lt  0                        topY   image Width   Math Sin -radAngle                     return new PointF  float topX   float topY              public Bitmap RotateImage double angle                SizeF size   CalculateSize radAngle           Bitmap rotatedBmp   new Bitmap  int size Width   int size Height            Graphics g   Graphics FromImage rotatedBmp           g InterpolationMode   System Drawing Drawing2D InterpolationMode HighQualityBicubic          g CompositingQuality   CompositingQuality HighQuality          g SmoothingMode   SmoothingMode HighQuality          g PixelOffsetMode   PixelOffsetMode HighQuality           g TranslateTransform topPoint X  topPoint Y           g RotateTransform GetDegree radAngle            g DrawImage image  new RectangleF 0  0  size Width  size Height             g Dispose            return rotatedBmp              public static class Builder               public static ImageRotator CreateInstance Image image                        ImageRotator rotator   new ImageRotator image as Bitmap               return rotator

User · Answer

Simple method   public Image RotateImage Image img        var bmp   new Bitmap img        using  Graphics gfx   Graphics FromImage bmp                 gfx Clear Color White           gfx DrawImage img  0  0  img Width  img Height              bmp RotateFlip RotateFlipType Rotate270FlipNone       return bmp

User · Answer

This is an old thread  and there are several other threads about C  WinForms image rotation  but now that I ve come up with my solution I figure this is as good a place to post it as any           lt summary gt        Method to rotate an Image object  The result can be one of three cases        - upsizeOk   true  output image will be larger than the input  and no clipping occurs        - upsizeOk   false  amp  clipOk   true  output same size as input  clipping occurs       - upsizeOk   false  amp  clipOk   false  output same size as input  image reduced  no clipping              A background color must be specified  and this color will fill the edges that are not        occupied by the rotated image  If color   transparent the output image will be 32-bit         otherwise the output image will be 24-bit               Note that this method always returns a new Bitmap object  even if rotation is zero - in        which case the returned object is a clone of the input object          lt  summary gt         lt param name  inputImage  gt input Image object  is not modified lt  param gt         lt param name  angleDegrees  gt angle of rotation  in degrees lt  param gt         lt param name  upsizeOk  gt see comments above lt  param gt         lt param name  clipOk  gt see comments above  not used if upsizeOk   true lt  param gt         lt param name  backgroundColor  gt color to fill exposed parts of the background lt  param gt         lt returns gt new Bitmap object  may be larger than input image lt  returns gt    public static Bitmap RotateImage Image inputImage  float angleDegrees  bool upsizeOk                                      bool clipOk  Color backgroundColor              Test for zero rotation and return a clone of the input image      if  angleDegrees    0f          return  Bitmap inputImage Clone             Set up old and new image dimensions  assuming upsizing not wanted and clipping OK      int oldWidth   inputImage Width       int oldHeight   inputImage Height       int newWidth   oldWidth       int newHeight   oldHeight       float scaleFactor   1f           If upsizing wanted or clipping not OK calculate the size of the resulting bitmap      if  upsizeOk     clipOk                 double angleRadians   angleDegrees   Math PI   180d           double cos   Math Abs Math Cos angleRadians            double sin   Math Abs Math Sin angleRadians            newWidth    int Math Round oldWidth   cos   oldHeight   sin           newHeight    int Math Round oldWidth   sin   oldHeight   cos                   If upsizing not wanted and clipping not OK need a scaling factor      if   upsizeOk  amp  amp   clipOk                 scaleFactor   Math Min  float oldWidth   newWidth   float oldHeight   newHeight           newWidth   oldWidth          newHeight   oldHeight                  Create the new bitmap object  If background color is transparent it must be 32-bit            otherwise 24-bit is good enough       Bitmap newBitmap   new Bitmap newWidth  newHeight  backgroundColor    Color Transparent                                          PixelFormat Format32bppArgb   PixelFormat Format24bppRgb        newBitmap SetResolution inputImage HorizontalResolution  inputImage VerticalResolution            Create the Graphics object that does the work      using  Graphics graphicsObject   Graphics FromImage newBitmap                  graphicsObject InterpolationMode   InterpolationMode HighQualityBicubic          graphicsObject PixelOffsetMode   PixelOffsetMode HighQuality          graphicsObject SmoothingMode   SmoothingMode HighQuality              Fill in the specified background color if necessary         if  backgroundColor    Color Transparent             graphicsObject Clear backgroundColor               Set up the built-in transformation matrix to do the rotation and maybe scaling         graphicsObject TranslateTransform newWidth   2f  newHeight   2f            if  scaleFactor    1f             graphicsObject ScaleTransform scaleFactor  scaleFactor            graphicsObject RotateTransform angleDegrees           graphicsObject TranslateTransform -oldWidth   2f  -oldHeight   2f               Draw the result          graphicsObject DrawImage inputImage  0  0                return newBitmap        This is the result of many sources of inspiration  here at StackOverflow and elsewhere  Naveen s answer on this thread was especially helpful

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