C#抓取当前屏幕并保存为图片的方法

本文实例讲述了c#抓取当前屏幕并保存为图片的方法。分享给大家供大家参考。具体分析如下：

这是一个c#实现的屏幕抓取程序，可以抓取整个屏幕保存为指定格式的图片，并且保存当前控制台缓存到文本

using system;
using system.collections.generic;
using system.componentmodel;
using system.diagnostics;
using system.drawing;
using system.drawing.imaging;
using system.io;
using system.runtime.interopservices;
using system.text;
using system.threading;
using system.windows.forms;
namespace robvanderwoude
{
 class printscreen
 {
  static int main( string[] args )
  {
   try
   {
    string output = string.empty;
    bool overwrite = false;
    bool text = false;
    imageformat type = null;
    #region command line parsing
    if ( args.length == 0 )
    {
     return writeerror( );
    }
    foreach ( string arg in args )
    {
     switch ( arg.toupper( ).substring( 0, 2 ) )
     {
      case "/?":
       return writeerror( );
      case "/o":
       overwrite = true;
       break;
      case "/t":
       if ( text )
       {
        return writeerror( "cannot capture current window as bitmap" );
       }
       switch ( arg.toupper( ).substring( 3 ) )
       {
        case "bmp":
         type = imageformat.bmp;
         break;
        case "gif":
         type = imageformat.gif;
         break;
        case "jpg":
        case "jpeg":
         type = imageformat.jpeg;
         break;
        case "png":
         type = imageformat.png;
         break;
        case "tif":
        case "tiff":
         type = imageformat.tiff;
         break;
        case "txt":
         text = true;
         break;
        default:
         return writeerror( "invalid file format: \"" + arg.substring( 4 ) + "\"" );
       }
       break;
      default:
       output = arg;
       break;
     }
    }
    // check if directory exists
    if ( !directory.exists( path.getdirectoryname( output ) ) )
    {
     return writeerror( "invalid path for output file: \"" + output + "\"" );
    }
    // check if file exists, and if so, if it can be overwritten
    if ( file.exists( output ) )
    {
     if ( overwrite )
     {
      file.delete( output );
     }
     else
     {
      return writeerror( "file exists; use /o to overwrite existing files." );
     }
    }
    if ( type == null && text == false )
    {
     string ext = path.getextension( output ).toupper( );
     switch ( ext )
     {
      case ".bmp":
       type = imageformat.bmp;
       break;
      case ".gif":
       type = imageformat.gif;
       break;
      case ".jpg":
      case ".jpeg":
       type = imageformat.jpeg;
       break;
      case ".png":
       type = imageformat.png;
       break;
      case ".tif":
      case ".tiff":
       type = imageformat.tiff;
       break;
      case ".txt":
       text = true;
       break;
      default:
       return writeerror( "invalid file type: \"" + ext + "\"" );
       return 1;
     }
    }
    #endregion command line parsing
    if ( text )
    {
     string readtext = string.empty;
     for ( short i = 0; i < (short) console.bufferheight; i++ )
     {
      foreach ( string line in consolereader.readfrombuffer( 0, i, (short) console.bufferwidth, 1 ) )
      {
       readtext += line + "\n";
      }
     }
     streamwriter file = new streamwriter( output );
     file.write( readtext );
     file.close( );
    }
    else
    {
     int width = screen.primaryscreen.bounds.width;
     int height = screen.primaryscreen.bounds.height;
     int top = 0;
     int left = 0;
     bitmap printscreen = new bitmap( width, height );
     graphics graphics = graphics.fromimage( printscreen as image );
     graphics.copyfromscreen( top, left, 0, 0, printscreen.size );
     printscreen.save( output, type );
    }
    return 0;
   }
   catch ( exception e )
   {
    console.error.writeline( e.message );
    return 1;
   }
  }
  #region error handling
  public static int writeerror( string errormessage = "" )
  {
   console.resetcolor( );
   if ( string.isnullorempty( errormessage ) == false )
   {
    console.error.writeline( );
    console.foregroundcolor = consolecolor.red;
    console.error.write( "error: " );
    console.foregroundcolor = consolecolor.white;
    console.error.writeline( errormessage );
    console.resetcolor( );
   }
   console.error.writeline( );
   console.error.writeline( "printscreen, version 1.10" );
   console.error.writeline( "save a screenshot as image or save the current console buffer as text" );
   console.error.writeline( );
   console.error.write( "usage:  " );
   console.foregroundcolor = consolecolor.white;
   console.error.writeline( "printscreen outputfile [ /t:type ] [ /o ]" );
   console.resetcolor( );
   console.error.writeline( );
   console.error.write( "where:  " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "outputfile" );
   console.resetcolor( );
   console.error.writeline( "  is the file to save the screenshot or text to" );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "   /t:type" );
   console.resetcolor( );
   console.error.write( "  specifies the file type: " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "bmp" );
   console.resetcolor( );
   console.error.write( ", " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "gif" );
   console.resetcolor( );
   console.error.write( ", " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "jpg" );
   console.resetcolor( );
   console.error.write( ", " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "png" );
   console.resetcolor( );
   console.error.write( ", " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "tif" );
   console.resetcolor( );
   console.error.write( " or " );
   console.foregroundcolor = consolecolor.white;
   console.error.writeline( "txt" );
   console.resetcolor( );
   console.error.write( "      (only required if " );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "outputfile" );
   console.resetcolor( );
   console.error.writeline( " extension is different)" );
   console.foregroundcolor = consolecolor.white;
   console.error.write( "   /o" );
   console.resetcolor( );
   console.error.writeline( "    overwrites an existing file" );
   console.error.writeline( );
   console.error.write( "credits: code to read console buffer by simon mourier " );
   console.foregroundcolor = consolecolor.darkgray;
   console.error.writeline( "http://www.sina.com.cn" );
   console.resetcolor( );
   console.error.write( "   code for graphic screenshot by ali hamdar " );
   console.foregroundcolor = consolecolor.darkgray;
   console.error.writeline( "//www.jb51.net" );
   console.resetcolor( );
   console.error.writeline( );
   console.error.writeline( "written by rob van der woude" );
   console.error.writeline( "http://www.qq.com" );
   return 1;
  }
  #endregion error handling
 }
 #region read from console buffer
 public class consolereader
 {
  public static ienumerable<string> readfrombuffer( short x, short y, short width, short height )
  {
   intptr buffer = marshal.allochglobal( width * height * marshal.sizeof( typeof( char_info ) ) );
   if ( buffer == null )
    throw new outofmemoryexception( );
   try
   {
    coord coord = new coord( );
    small_rect rc = new small_rect( );
    rc.left = x;
    rc.top = y;
    rc.right = (short) ( x + width - 1 );
    rc.bottom = (short) ( y + height - 1 );
    coord size = new coord( );
    size.x = width;
    size.y = height;
    const int std_output_handle = -11;
    if ( !readconsoleoutput( getstdhandle( std_output_handle ), buffer, size, coord, ref rc ) )
    {
     // 'not enough storage is available to process this command' may be raised for buffer size > 64k (see readconsoleoutput doc.)
     throw new win32exception( marshal.getlastwin32error( ) );
    }
    intptr ptr = buffer;
    for ( int h = 0; h < height; h++ )
    {
     stringbuilder sb = new stringbuilder( );
     for ( int w = 0; w < width; w++ )
     {
      char_info ci = (char_info) marshal.ptrtostructure( ptr, typeof( char_info ) );
      char[] chars = console.outputencoding.getchars( ci.chardata );
      sb.append( chars[0] );
      ptr += marshal.sizeof( typeof( char_info ) );
     }
     yield return sb.tostring( );
    }
   }
   finally
   {
    marshal.freehglobal( buffer );
   }
  }
  [structlayout( layoutkind.sequential )]
  private struct char_info
  {
   [marshalas( unmanagedtype.byvalarray, sizeconst = 2 )]
   public byte[] chardata;
   public short attributes;
  }
  [structlayout( layoutkind.sequential )]
  private struct coord
  {
   public short x;
   public short y;
  }
  [structlayout( layoutkind.sequential )]
  private struct small_rect
  {
   public short left;
   public short top;
   public short right;
   public short bottom;
  }
  [structlayout( layoutkind.sequential )]
  private struct console_screen_buffer_info
  {
   public coord dwsize;
   public coord dwcursorposition;
   public short wattributes;
   public small_rect srwindow;
   public coord dwmaximumwindowsize;
  }
  [dllimport( "kernel32.dll", setlasterror = true )]
  private static extern bool readconsoleoutput( intptr hconsoleoutput, intptr lpbuffer, coord dwbuffersize, coord dwbuffercoord, ref small_rect lpreadregion );
  [dllimport( "kernel32.dll", setlasterror = true )]
  private static extern intptr getstdhandle( int nstdhandle );
 }
 #endregion read from console buffer
}

希望本文所述对大家的c#程序设计有所帮助。