开发者

thumbnail generation error c#

开发者 https://www.devze.com 2023-02-18 15:58 出处:网络
i am trying to create thumbnails. my path to original folder is: suppose I:\\my images**, and i want to generate it to **i:\\new images. i got two problem, first problem is that if my images folder co

i am trying to create thumbnails. my path to original folder is: suppose I:\my images**, and i want to generate it to **i:\new images. i got two problem, first problem is that if my images folder contains subfolder then in the new images it should also be in the sub folder not as a parent folder .

  • second i got an Error.**A generic error occurred in GDI+.

    3rd i get this error: Out of memory.**

its a csharp console application

at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
at System.Drawing.Image.Save(String filename, ImageFormat format)
at ConsoleApplication1.Program.CreateThumbnail(String[] b, Double wid, Double hght, Boolean Isprint)

public void CreateThumbnail(string[] b, double wid, double hght, bool Isprint)
{
    string[] path;
    path = new string [64];
    path = b;
    string saveath = "i:\\check\\a test\\";
    for (int i = 0; i < b.Length; i++)
    {
        DirectoryInfo dir = new DirectoryInfo(path[i]);
        string dir1 = dir.ToString();
        dir1 = dir1.Substring(dir1.LastIndexOf("\\"));

        FileInfo[] files1 = dir.GetFiles();

        foreach (FileInfo f in files1)
        {
            string gh = f.ToString();
            try
            {
                System.Drawing.Image myThumbnail150;
                System.Drawing.Image.GetThumbnailImageAbort myCallback = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
                System.Drawing.Image imagesize = System.Drawing.Image.FromFile(f.FullName);
                Bitmap bitmapNew = new Bitmap(imagesize);
                double maxWidth = wid;
                double maxHeight = hght;
                int w = imagesize.Width;
                int h = imagesize.Height;
                // Longest and shortest dimension 
                int longestDimension = (w > h) ? w : h;
                int shortestDimension = (w < h) ? w : h;
                // propotionality  
                float factor = ((float)longestDimension) / shortestDimension;
                // default width is greater than height    
                double newWidth = maxWidth;
                double newHeight = maxWidth / factor;
                // if height greater than width recalculate  
                if (w < h)
                {
                    newWidth = maxHeight / factor;
                    newHeight = maxHeight;
                }
                myThumbnail150 = bitmapNew.GetThumbnailImage((int)newWidth, (int)newHeight, myCallback, IntPtr.Zero);

                string ext = Path.GetExtension(f.Name);

                if (!Directory.Exists(saveath + dir1))
                {
                    Directory.CreateDirectory(saveath + dir1);
                    myThumbnail150.Save(saveath + dir1 + "\\" + f.Name.Replace(ext, ".Jpeg"), System.Drawing.Imaging.ImageFormat.Jpeg);
                }
                else if(Directory.Exists(saveath+dir1))
    开发者_JAVA技巧            {
                    myThumbnail150.Save(saveath + dir1+" \\"+ f.Name.Replace(ext, ".Jpeg"), System.Drawing.Imaging.ImageFormat.Jpeg);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("something went wrong" + ex.ToString());
            }
        }
    }
}


I have just refactored a bit the code and now it works (on my machine):

private static void CreateThumbnail(string[] b, double wid, double hght, bool Isprint)
{
    string saveAt = "D:\\check";
    foreach (string path in b)
    {
        var directory = new DirectoryInfo(path);
        string outputPath = Path.Combine(saveAt, directory.Name);
        foreach (FileInfo f in directory.GetFiles("*.*", SearchOption.AllDirectories))
        {
            if (f.DirectoryName != directory.FullName)
            {
                outputPath = Path.Combine(saveAt, directory.Name, f.Directory.Name);
            }
            if (!Directory.Exists(outputPath))
            {
                Directory.CreateDirectory(outputPath);
            }

            using (Image imagesize = Image.FromFile(f.FullName))
            using (Bitmap bitmapNew = new Bitmap(imagesize))
            {
                double maxWidth = wid;
                double maxHeight = hght;
                int w = imagesize.Width;
                int h = imagesize.Height;
                // Longest and shortest dimension 
                int longestDimension = (w > h) ? w : h;
                int shortestDimension = (w < h) ? w : h;
                // propotionality  
                float factor = ((float)longestDimension) / shortestDimension;
                // default width is greater than height    
                double newWidth = maxWidth;
                double newHeight = maxWidth / factor;
                // if height greater than width recalculate  
                if (w < h)
                {
                    newWidth = maxHeight / factor;
                    newHeight = maxHeight;
                }

                string fileName = Path.Combine(outputPath, Path.GetFileNameWithoutExtension(f.Name) + ".jpeg");
                bitmapNew.GetThumbnailImage((int)newWidth, (int)newHeight, () => false, IntPtr.Zero)
                    .Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
        }
    }
}

I have to say few things about your old code:

  • use foreach when possible;
  • avoid the first three lines, they are useless;
  • avoid unused variables;
  • keep your code as clean as possible;


About the "GDI+ generic error" and the "Out Of Memory" exceptions, you should take a look at that link on SO: What is the "best" way to create a thumbnail using ASP.NET?

You must use the C# using statement to make sure unmanaged GDI+ resources underneath the .NET surface are freed as quickly as possible to avoid out of memory errors.

The GDI+ generic can happen if the image cannot be converted for example.

0

精彩评论

暂无评论...
验证码 换一张
取 消