Пример #1
0
        internal GraphicEx GetGraphicControlExtension(Stream stream)
        {
            GraphicEx gex       = new GraphicEx();
            int       blockSize = Read();

            if (blockSize != GraphicEx.BlockSize)
            {
                throw new Exception("数据格式错误!");
            }
            gex.Packed           = (byte)Read();
            gex.TransparencyFlag = (gex.Packed & 0x01) == 1;
            gex.DisposalMethod   = (gex.Packed & 0x1C) >> 2;
            gex.Delay            = ReadShort();
            gex.TranIndex        = (byte)Read();
            Read();
            return(gex);
        }
Пример #2
0
        internal static GifImage Decode(string gifPath)
        {
            FileStream       fs           = null;
            StreamHelper     streamHelper = null;
            GifImage         gifImage     = new GifImage();
            List <GraphicEx> graphics     = new List <GraphicEx>();
            int frameCount = 0;

            try
            {
                fs              = new FileStream(gifPath, FileMode.Open);
                streamHelper    = new StreamHelper(fs);
                gifImage.Header = streamHelper.ReadString(6);
                gifImage.LogicalScreenDescriptor = streamHelper.GetLCD(fs);
                if (gifImage.LogicalScreenDescriptor.GlobalColorTableFlag)
                {
                    gifImage.GlobalColorTable = streamHelper.ReadByte(gifImage.LogicalScreenDescriptor.GlobalColorTableSize * 3);
                }
                int nextFlag = streamHelper.Read();
                while (nextFlag != 0)
                {
                    if (nextFlag == GifExtensions.ImageLabel)
                    {
                        ReadImage(streamHelper, fs, gifImage, graphics, frameCount);
                        frameCount++;
                    }
                    else if (nextFlag == GifExtensions.ExtensionIntroducer)
                    {
                        int gcl = streamHelper.Read();
                        switch (gcl)
                        {
                        case GifExtensions.GraphicControlLabel:
                        {
                            GraphicEx graphicEx = streamHelper.GetGraphicControlExtension(fs);
                            graphics.Add(graphicEx);
                            break;
                        }

                        case GifExtensions.CommentLabel:
                        {
                            CommentEx comment = streamHelper.GetCommentEx(fs);
                            gifImage.CommentExtensions.Add(comment);
                            break;
                        }

                        case GifExtensions.ApplicationExtensionLabel:
                        {
                            ApplicationEx applicationEx = streamHelper.GetApplicationEx(fs);
                            gifImage.ApplictionExtensions.Add(applicationEx);
                            break;
                        }

                        case GifExtensions.PlainTextLabel:
                        {
                            PlainTextEx textEx = streamHelper.GetPlainTextEx(fs);
                            gifImage.PlainTextEntensions.Add(textEx);
                            break;
                        }
                        }
                    }
                    else if (nextFlag == GifExtensions.EndIntroducer)
                    {
                        break;
                    }
                    nextFlag = streamHelper.Read();
                }
            }
            catch
            {
                throw;
            }
            finally
            {
                fs.Close();
            }
            return(gifImage);
        }