截图和压缩图片

截图(全屏):

   private void tsbScreenshot_Click(object sender,
EventArgs e)

        {

            try

            {

                Graphics g =
Graphics.FromImage(myImage);

                g.CopyFromScreen(new
Point(0, 0), new
Point(0, 0), new
Size(Screen.PrimaryScreen.Bounds.Width,
Screen.PrimaryScreen.Bounds.Height));

                IntPtr dc1 = g.GetHdc();

                g.ReleaseHdc(dc1);

                string FileName =
Application.StartupPath + "\\Records\\" +
DateTime.Now.ToString("yyyyMMdd_hhmmss") +
".jpg";

                myImage.Save(FileName);               

                g.Dispose();

                if (CompressImage(FileName, FileName, 50) ==
true)

                {

                    File.Delete(FileName);

                }

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.Message);

            }

        }

压缩:

     public static
bool CompressImage(string InputFileAddress,
string OutputFileAddress,
int CompressionRate)

        {

            System.Drawing.Image iSource = System.Drawing.Image.FromFile(InputFileAddress);

            ImageFormat tFormat = iSource.RawFormat;

            //以下代码为保存图片时，设置压缩质量 

            EncoderParameters ep =
new EncoderParameters();

            long[] qy =
new long[1];

            qy[0] = CompressionRate;//设置压缩的比例1-100 

            EncoderParameter eParam =
new EncoderParameter(System.Drawing.Imaging.Enco
4000
der.Quality, qy);

            ep.Param[0] = eParam;

            try

            {

                ImageCodecInfo[] arrayICI =
ImageCodecInfo.GetImageEncoders();

                ImageCodecInfo jpegICIinfo =
null;

                for (int x = 0; x < arrayICI.Length; x++)

                {

                    if (arrayICI[x].FormatDescription.Equals("JPEG"))

                    {

                        jpegICIinfo =arrayICI[x];

                        break;

                    }

                }

                if (jpegICIinfo !=
null)

                {

                   iSource.Save(OutputFileAddress, jpegICIinfo, ep);//dFile是压缩后的新路径 

                }

                else

                {

                   iSource.Save(OutputFileAddress, tFormat);

                }

                return
true;

            }

            catch

            {

                return
false;

            }

            finally

            {

                iSource.Dispose();

            }

        }