C# Bitmap.GetThumbnailImage方法代码示例

    public static Stream CreateCircleImageStream(Stream imgStream, int circleDiameter)
    {
        //convert stream to bitmap
        Bitmap imgBitmap = new Bitmap(imgStream);

        //for debug
        //saveImage(imgBitmap, "3 inputsteam to bitmap.jpg");

        //create squre image with circle drawn
        imgBitmap = CreateSqureImageAndDrawCicle(imgBitmap, circleDiameter * resizeScale);

        //create circle image
        imgBitmap = CropImageToCircle(imgBitmap);

        //for debug
        //saveImage(imgBitmap, "6 circle croped.jpg");

        //reduce size
        System.Drawing.Image resizedImage = imgBitmap.GetThumbnailImage(circleDiameter, circleDiameter, null, System.IntPtr.Zero);

        //debug
        //saveImage(resizedImage, "7 resized.jpg");

        //convert bitmap to stream
        Stream outputStream = new MemoryStream();
        resizedImage.Save(outputStream, System.Drawing.Imaging.ImageFormat.Png);//jpg does not support transparency

        resizedImage.Dispose();
        imgBitmap.Dispose();

        return outputStream;
    }

    public void ProcessRequest(HttpContext context)
    {
        string ImageUrl = context.Request.QueryString["url"];
        //get image width to be resized from querystring
        string ImageWidth = context.Request.QueryString["width"];
        //get image height to be resized from querystring
        string ImageHeight = context.Request.QueryString["height"];
        if (ImageUrl != string.Empty && ImageHeight != string.Empty && ImageWidth != string.Empty && (ImageWidth != null && ImageHeight != null))
        {
            if (!System.Web.UI.WebControls.Unit.Parse(ImageWidth).IsEmpty && !System.Web.UI.WebControls.Unit.Parse(ImageHeight).IsEmpty)
            {
                Image.GetThumbnailImageAbort myCallback = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                //creat BitMap object from image path passed in querystring
                Bitmap BitmapForImage = new Bitmap(context.Server.MapPath(ImageUrl));
                //create unit object for height and width. This is to convert parameter passed in differen unit like pixel, inch into generic unit.
                System.Web.UI.WebControls.Unit WidthUnit = System.Web.UI.WebControls.Unit.Parse(ImageWidth);
                System.Web.UI.WebControls.Unit HeightUnit = System.Web.UI.WebControls.Unit.Parse(ImageHeight);
                //Resize actual image using width and height paramters passed in querystring
                Image CurrentThumbnail = BitmapForImage.GetThumbnailImage(Convert.ToInt16(WidthUnit.Value), Convert.ToInt16(HeightUnit.Value), myCallback, IntPtr.Zero);
                //Create memory stream and save resized image into memory stream
                MemoryStream objMemoryStream = new MemoryStream();
                if (ImageUrl.EndsWith(".png"))
                {
                    context.Response.ContentType = "image/png";
                    CurrentThumbnail.Save(objMemoryStream, System.Drawing.Imaging.ImageFormat.Png);
                }
                else if (ImageUrl.EndsWith(".jpg"))
                {
                    context.Response.ContentType = "image/jpeg";
                    CurrentThumbnail.Save(objMemoryStream, System.Drawing.Imaging.ImageFormat.Jpeg);
                }
                else if (ImageUrl.EndsWith(".gif"))
                {
                    context.Response.ContentType = "image/gif";
                    CurrentThumbnail.Save(objMemoryStream, System.Drawing.Imaging.ImageFormat.Gif);
                }

                //Declare byte array of size memory stream and read memory stream data into array
                byte[] imageData = new byte[objMemoryStream.Length];
                objMemoryStream.Position = 0;
                objMemoryStream.Read(imageData, 0, (int)objMemoryStream.Length);

                //send contents of byte array as response to client (browser)
                context.Response.BinaryWrite(imageData);
            }
        }
        else
        {
            //if width and height was not passed as querystring, then send image as it is from path provided.
            context.Response.WriteFile(context.Server.MapPath(ImageUrl));
        }
    }

    static void Main(string[] args)
    {
        //入力JPEG読み込み
        var inputImg = new Bitmap(args[1]);

        //変換後の横幅
        int toWidth = int.Parse(args[0]);

        double rate = (double)toWidth / inputImg.Width;

        //変換後の縦幅
        int toHeight = (int)(inputImg.Height * rate);

        //サムネイル画像作成
        var outputImg = inputImg.GetThumbnailImage(toWidth, toHeight, () => true, new IntPtr());

        //サムネイル画像出力
        outputImg.Save(args[2]);
    }

    public static bool UploadImage(Stream stream, string filename)
    {
        System.Drawing.Image image = null;
        try
        {
            bool bCreateThumb = false;
            image = new Bitmap(stream);
            int width = image.Width;
            int height = image.Height;
            if (width > 240)
            {
                bCreateThumb = true;
                height = (int)(height * 240 / width);
                width = 240;
            }
            if (height > 180)
            {
                bCreateThumb = true;
                width = (int)(width * 180 / height);
                height = 180;
            }
            if (bCreateThumb)
                image = image.GetThumbnailImage(width, height, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);
            if (File.Exists(filename))
                File.Delete(filename);
            image.Save(filename);
        }
        catch
        {
            return false;
        }
        finally
        {
            image = null;
        }
        

        return true;
    }

    //private const string savePath = @"F:\WebDegsin\作品集\According2\Data_Temp\";
    //private const string tempPath = @"F:\WebDegsin\作品集\According2\img\";
    protected void Button1_Click(object sender, EventArgs e)
    {
        string tempPath = Server.MapPath("~/Data_Temp/");
        string savePath = Server.MapPath("~/img/");
        if (FileUpload1.HasFile)
        {
            string tempName = tempPath + FileUpload1.FileName;
            string imageName = savePath + FileUpload1.FileName;

            // 儲存暫存檔
            FileUpload1.SaveAs(tempName);

            // System.Web.UI.WebControls 與 System.Drawing 同時擁有 Image 類別
            // 所以以下程式碼明確指定要使用的是 System.Drawing.Image

            System.Drawing.Image.GetThumbnailImageAbort callBack = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
            Bitmap image = new Bitmap(tempName);

            // 計算維持比例的縮圖大小
            int[] thumbnailScale = getThumbnailImageScale(600, 600, image.Width, image.Height);

            // 產生縮圖
            System.Drawing.Image smallImage = image.GetThumbnailImage(thumbnailScale[0], thumbnailScale[1], callBack, IntPtr.Zero);

            // 將縮圖存檔
            smallImage.Save(imageName);

            // 釋放並刪除暫存檔
            image.Dispose();
            System.IO.File.Delete(tempName);
            Response.Write("ok");
        }
        else
        {
            Response.Write("error");
        }
    }

    public static Bitmap ResizeImage(Bitmap fullsizeImage, int maxWidth, int maxHeight, string imageName)
    {
        fullsizeImage.RotateFlip(RotateFlipType.Rotate180FlipNone);
        fullsizeImage.RotateFlip(RotateFlipType.Rotate180FlipNone);

        int imageWidth;
        int imageHeight;

        var newWidth = maxHeight * fullsizeImage.Width / fullsizeImage.Height;
        if (newWidth > maxWidth)
        {
            imageHeight = fullsizeImage.Height * maxWidth / fullsizeImage.Width;
            imageWidth = maxWidth;
        }
        else
        {
            imageWidth = newWidth;
            imageHeight = maxHeight;
        }
        System.Drawing.Image newImage = fullsizeImage.GetThumbnailImage(imageWidth, imageHeight, null, IntPtr.Zero);
        fullsizeImage.Dispose();

        return (Bitmap)newImage;
    }

    private byte[] GenThumb(byte[] buffer, ImageFormat format, string type)
    {
        MemoryStream iMS = new MemoryStream(buffer);
        System.Drawing.Image img = new Bitmap(iMS);

        int h = -1;

        switch (type)
        {
            case "n":
                h = img.Height / (img.Width / 128);
                break;
            case "t":
                h = 96;
                break;
            default:
                break;
        }

        System.Drawing.Image thumb = img.GetThumbnailImage(128, h, null, new IntPtr());

        MemoryStream tMS = new MemoryStream();
        thumb.Save(tMS, format);

        //Array.Resize(ref buffer, 0);

        return tMS.ToArray();
    }

    private string CreateThumbnail(string path, string filename)
    {
        System.Drawing.Image myThumbnail150;
        System.Drawing.Image imagesize = System.Drawing.Image.FromFile(path);
        Bitmap bitmapNew = new Bitmap(imagesize);
        if (imagesize.Width < imagesize.Height)
            myThumbnail150 = bitmapNew.GetThumbnailImage(150 * imagesize.Width / imagesize.Height, 150, myCallback, IntPtr.Zero);
        else
            myThumbnail150 = bitmapNew.GetThumbnailImage(150, imagesize.Height * 150 / imagesize.Width, myCallback, IntPtr.Zero);

        myThumbnail150.Save(ConfigurationManager.AppSettings["LogoUploadLocation"] + Request.QueryString["OrganizationId"] + "/" + filename + "-t.png", System.Drawing.Imaging.ImageFormat.Png);
        return filename + "-t.png";
    }

    private void SaveBannerContent(int BannerId, int ImageId)
    {
        try
        {
            bool isEdit = false;
            SageBannerInfo obj = new SageBannerInfo();
            if (Session["EditImageID"] != null && Session["EditImageID"].ToString() != string.Empty)
            {
                obj.ImageID = Int32.Parse(Session["EditImageID"].ToString());
                if (fuFileUpload.HasFile)
                {
                    obj.ImagePath = fuFileUpload.PostedFile.FileName.Replace(" ", "_");
                    obj.NavigationImage = fuFileUpload.PostedFile.FileName.Replace(" ", "_");
                }
                else
                {
                    isEdit = true;
                    obj.ImagePath = Convert.ToString(Session["ImageName"]);
                    obj.NavigationImage = Convert.ToString(Session["ImageName"]);
                }
            }
            else
            {
                obj.ImageID = 0;
                obj.ImagePath = fuFileUpload.FileName.Replace(" ", "_");
                obj.NavigationImage = fuFileUpload.FileName.Replace(" ", "_");
            }
            obj.Caption = string.Empty;
            if (rdbReadMorePageType.SelectedItem.Text == "Page")
            {
                obj.ReadMorePage = ddlPagesLoad.SelectedValue.ToString();
                obj.LinkToImage = string.Empty;
            }
            if (rdbReadMorePageType.SelectedItem.Text == "Web Url")
            {
                obj.LinkToImage = txtWebUrl.Text;
                obj.ReadMorePage = string.Empty;
            }
            obj.UserModuleID = Int32.Parse(SageUserModuleID);
            obj.BannerID = BannerId;
            obj.ImageID = ImageId;
            obj.ReadButtonText = txtReadButtonText.Text;
            obj.Description = txtBannerDescriptionToBeShown.Text.Trim();
            obj.PortalID = GetPortalID;
            obj.CultureCode = GetCurrentCulture();
            string swfExt = System.IO.Path.GetExtension(fuFileUpload.PostedFile.FileName);
            if (swfExt == ".swf")
            {
                if (fuFileUpload.FileContent.Length > 0)
                {
                    string Path = GetUplaodImagePhysicalPath();
                    string fileName = fuFileUpload.PostedFile.FileName.Replace(" ", "_");
                    DirectoryInfo dirUploadImage = new DirectoryInfo(Path);
                    if (dirUploadImage.Exists == false)
                    {
                        dirUploadImage.Create();
                    }
                    string fileUrl = Path + fileName;
                    int i = 1;
                    while (File.Exists(fileUrl))
                    {

                        fileName = i + fileName;
                        fileUrl = Path + i + fileName;
                        i++;
                    }
                    fuFileUpload.PostedFile.SaveAs(fileUrl);
                    swfFileName = "Modules/Sage_Banner/images/" + fileName;
                    obj.ImagePath = fileName;
                    obj.NavigationImage = fileName;
                }
            }
            else
            {
                string target = Server.MapPath("~/Modules/Sage_Banner/images/OriginalImage");
                string CropImageTarget = Server.MapPath("~/Modules/Sage_banner/images/CroppedImages");
                string thumbTarget = Server.MapPath("~/Modules/Sage_Banner/images/ThumbNail");
                System.Drawing.Image.GetThumbnailImageAbort thumbnailImageAbortDelegate = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
                if (fuFileUpload.HasFile)
                {
                    string fileName = fuFileUpload.PostedFile.FileName.Replace(" ", "_");
                    int i = 1;
                    while (File.Exists(target + "/" + fileName))
                    {
                        fileName = i + fileName;
                        i++;
                    }
                    fuFileUpload.SaveAs(Path.Combine(target, fileName));
                    fuFileUpload.SaveAs(Path.Combine(CropImageTarget, fileName));
                    using (Bitmap originalImage = new Bitmap(fuFileUpload.PostedFile.InputStream))
                    {
                        using (System.Drawing.Image thumbnail = originalImage.GetThumbnailImage(80, 80, thumbnailImageAbortDelegate, IntPtr.Zero))
                        {
                            thumbnail.Save(Path.Combine(thumbTarget, fileName));
                        }
                    }
                    obj.ImagePath = fileName;
                    obj.NavigationImage = fileName;
                }
            }
//.........这里部分代码省略.........

    public void ProcessRequest(HttpContext ctx)
    {
        // let's cache this for 1 day//no cache ŞY
        ctx.Response.ContentType = "image/jpeg";
        //ctx.Response.Cache.SetCacheability(HttpCacheability.Public);
        //ctx.Response.Cache.SetExpires(DateTime.Now.AddDays(1));

        // find the directory where we're storing the images
        //string imageDir = ConfigurationSettings.AppSettings["imageDir"];
        //imageDir = Path.Combine(
        //    ctx.Request.PhysicalApplicationPath, imageDir);

        // find the image that was requested
        //string file = ctx.Request.PhysicalApplicationPath + path;
        string file = path;
        //     file = Path.Combine(imageDir, file);
        // load it up
        using (System.Drawing.Image img = new Bitmap(file))
        {
            // do some math to resize the image
            // note: i know very little about image resizing,
            // but this just seemed to work under v1.1. I think
            // under v2.0 the images look incorrect.
            // *note to self* fix this for v2.0
            //int h = img.Height;
            //int w = img.Width;
            //int b = h > w ? h : w;
            //double per = (b > MaxDim) ? (MaxDim * 1.0) / b : 1.0;
            //h = 136;//(int)(h * per);
            //w = 184;//(int)(w * per);

            // create the thumbnail image
            using (System.Drawing.Image img2 =
                      img.GetThumbnailImage(width, height,
                      new System.Drawing.Image.GetThumbnailImageAbort(Abort),
                      IntPtr.Zero))
            {
                // emit it to the response strea,
                img2.Save(ctx.Response.OutputStream,
                    System.Drawing.Imaging.ImageFormat.Jpeg);
            }
        }
    }

    /// <summary>
    /// To create new image with new dimensions.
    /// </summary>
    /// <param name="smallImgPath">Source Img</param>
    /// <param name="bigImgPath">Destination Img</param>
    /// <param name="width">New Width</param>
    /// <param name="height">New Height</param>
    private void SaveThumbnail(string smallImgPath, string bigImgPath, int width, int height)
    {
        Encoder myEncoder;
        EncoderParameter myEncoderParameter;
        EncoderParameters myEncoderParameters=new EncoderParameters();
        ImageCodecInfo myImageCodecInfo;
        // Get an ImageCodecInfo object that represents the JPEG codec.
        myImageCodecInfo = GetEncoderInfo("image/png");
        System.Drawing.Image.GetThumbnailImageAbort myCallback = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
        Bitmap myBitmap = new Bitmap(smallImgPath);
        // for the Quality parameter category.
        myEncoder = Encoder.Quality;
        // Save the bitmap as a JPEG file with quality level 50.
        myEncoderParameter = new EncoderParameter(myEncoder, 100L);
        myEncoderParameters.Param[0] = myEncoderParameter;
        int imageHeight = (int)((width * myBitmap.Height) / myBitmap.Width);
        int imageWidth = (int)((height * myBitmap.Width) / myBitmap.Height);
        System.Drawing.Image myThumbnail = myBitmap.GetThumbnailImage(imageWidth, height, myCallback, IntPtr.Zero);

        myThumbnail.Save(bigImgPath, myImageCodecInfo, myEncoderParameters);
        myBitmap.Dispose();
        myThumbnail.Dispose();
    }

    public byte[][] GalleryImagesData(string target, string legal)
    {
        byte[][] buffer = { };

        try
        {
            string tbl = "pics";
            string sqlStr = "SELECT * FROM " + tbl;

            OleDbConnection cnn = new OleDbConnection(Base.cnnStrPics);

            cnn.Open();

            OleDbCommand cmd = new OleDbCommand(sqlStr, cnn);
            OleDbDataReader drr = cmd.ExecuteReader();

            while (drr.Read())
            {
                if (drr["location"].ToString().Trim() == target.ToString().Trim())
                {
                    int len = buffer.Length;
                    Array.Resize(ref buffer, len + 1);

                    MemoryStream iMS = new MemoryStream(Convert.FromBase64String(drr["data"].ToString()));
                    Image img = new Bitmap(iMS);

                    Image thumb = img.GetThumbnailImage(128, 96, null, new IntPtr());

                    MemoryStream tMS = new MemoryStream();
                    thumb.Save(tMS, ImageFormat.Jpeg);

                    buffer[len] = tMS.ToArray();
                }
            }

            cnn.Close();
            drr.Close();

            cmd.Dispose();
            drr.Dispose();
            cnn.Dispose();

            cmd = null;
            drr = null;
            cnn = null;
        }
        catch
        {
        }
        finally
        {
        }

        return buffer;
    }

    private static Bitmap CreateSqureImageAndDrawCicle(Bitmap fullSizeImg, int Size)
    {
        int width = fullSizeImg.Width;
        int height = fullSizeImg.Height;
        int x = 0;
        int y = 0;

        //Determine dimensions of resized version of the image
        if (width > height)
        {
            width = (int)(width / height) * Size;
            height = Size;
            // moves cursor so that crop is more centered
            x = Convert.ToInt32(Math.Ceiling((double)((width - height) / 2)));
        }
        else if (height > width)
        {
            height = (int)(height / width) * Size;
            width = Size;
            // moves cursor so that crop is more centered
            y = Convert.ToInt32(Math.Ceiling((double)((height - width) / 2)));
        }
        else
        {
            width = Size;
            height = Size;
        }

        //First Resize the Existing Image
        System.Drawing.Image thumbNailImg = fullSizeImg.GetThumbnailImage(width, height, null, System.IntPtr.Zero);

        //debug
        //saveImage(thumbNailImg, "4 thumbNailImg.jpg");

        //Clean up / Dispose...
        fullSizeImg.Dispose();

        //Create a Crop Frame to apply to the Resized Image
        Bitmap myBitmapCropped = new Bitmap(width, height);//PixelFormat.Format16bppRgb555
        myBitmapCropped.SetResolution(thumbNailImg.HorizontalResolution, thumbNailImg.VerticalResolution);

        Graphics myGraphic = FromImage(myBitmapCropped);

        //Apply the Crop to the Resized Image
        myGraphic.DrawImage(thumbNailImg, new Rectangle(0, 0, myBitmapCropped.Width, myBitmapCropped.Height),
            x, y, myBitmapCropped.Width, myBitmapCropped.Height, GraphicsUnit.Pixel);

        //draw boarder
        myGraphic.DrawEllipse(new Pen(Color.White, borderSize),
            new Rectangle(0, 0, myBitmapCropped.Width, myBitmapCropped.Height));

        //Clean up / Dispose...
        myGraphic.Dispose();

        //debug
        //saveImage(myBitmapCropped, "5 circle drawn.jpg");

        //Clean up / Dispose...
        thumbNailImg.Dispose();
        return myBitmapCropped;
    }

 private string CreateThumbnail(string path, string filename, int orgId)
 {
     try
     {
         System.Drawing.Image myThumbnail150;
         System.Drawing.Image imagesize = System.Drawing.Image.FromFile(path);
         Bitmap bitmapNew = new Bitmap(imagesize);
         if (imagesize.Width < imagesize.Height)
             myThumbnail150 = bitmapNew.GetThumbnailImage(100 * imagesize.Width / imagesize.Height, 100, myCallback, IntPtr.Zero);
         else
             myThumbnail150 = bitmapNew.GetThumbnailImage(100, imagesize.Height * 100 / imagesize.Width, myCallback, IntPtr.Zero);
         myThumbnail150.Save(Server.MapPath(ConfigurationManager.AppSettings["LogoUploadLocation"] + orgId.ToString() + "/" + filename + "-t.png"), System.Drawing.Imaging.ImageFormat.Png);
         return filename + "-t.png";
     }
     catch (Exception ex)
     {
         new SqlLog().InsertSqlLog(0, "logo-setting.aspx CreateThumbnail", ex);
         return null;
     }
 }

		public static Bitmap GetThumnailImage(Bitmap OriginalImage, int MaxExtent)
		{
			float AspectRatio = OriginalImage.Width / OriginalImage.Height;
			float SizeRatio;
			int NewWidth, NewHeight;

			if (AspectRatio == 0)
				return (Bitmap)OriginalImage.GetThumbnailImage(MaxExtent, MaxExtent, null, IntPtr.Zero);
			else if (AspectRatio > 1)
			{
				if (OriginalImage.Width < MaxExtent)
					return (Bitmap)OriginalImage.Clone();

				SizeRatio = MaxExtent / OriginalImage.Width;
			}
			else //AspectRation >1
			{
				if (OriginalImage.Height < MaxExtent)
					return (Bitmap)OriginalImage.Clone();

				SizeRatio = MaxExtent / OriginalImage.Height;
			}

			NewWidth = (int)((float)OriginalImage.Width * SizeRatio);
			NewHeight = (int)((float)OriginalImage.Height * SizeRatio);
			return GetThumnailImage(OriginalImage, NewWidth, NewHeight);
		}