C# 给图片添加水印 图片类型转换

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using Microsoft.Win32;
using System.Runtime.InteropServices;
using System.Drawing.Imaging;
//Download by http://www.codefans.net
namespace PictureManage
{
    public partial class frmMain : Form
    {
        public frmMain（）
        {
            InitializeComponent（）;
        }

        #region 自定义方法
        public int Pindex;
        public string TPath（）
        {
            string TemporaryPath;
            TemporaryPath = Application.StartupPath.ToString（）;
            TemporaryPath = TemporaryPath.Substring（0 TemporaryPath.LastIndexOf（“\\“））;
            TemporaryPath = Temp

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件       3348  2014-10-29 09:22  _UpgradeReport_Files\UpgradeReport.css

     文件      12505  2010-05-04 01:19  _UpgradeReport_Files\UpgradeReport.xslt

     文件         69  2014-10-29 09:22  _UpgradeReport_Files\UpgradeReport_Minus.gif

     文件         71  2014-10-29 09:22  _UpgradeReport_Files\UpgradeReport_Plus.gif

     文件      25448  2013-05-11 11:32  Backup\PictureManage\frmMain.cs

     文件      44703  2013-05-11 11:32  Backup\PictureManage\frmMain.Designer.cs

     文件      31449  2008-08-18 15:23  Backup\PictureManage\frmMain.resx

     文件       7058  2008-06-26 16:34  Backup\PictureManage\frmPicAdjust.cs

     文件      12741  2008-06-17 16:53  Backup\PictureManage\frmPicAdjust.Designer.cs

     文件      10509  2008-06-17 16:53  Backup\PictureManage\frmPicAdjust.resx

     文件       1481  2008-06-06 13:17  Backup\PictureManage\frmPictureMax.cs

     文件       2911  2008-06-06 13:09  Backup\PictureManage\frmPictureMax.Designer.cs

     文件       5814  2008-06-06 13:09  Backup\PictureManage\frmPictureMax.resx

     文件       2304  2013-05-11 17:51  Backup\PictureManage\frmRename.cs

     文件       5229  2008-08-05 10:48  Backup\PictureManage\frmRename.Designer.cs

     文件      10588  2008-08-05 10:48  Backup\PictureManage\frmRename.resx

     文件       2392  2013-05-11 11:32  Backup\PictureManage\frmSlide.cs

     文件       6227  2008-06-17 16:57  Backup\PictureManage\frmSlide.Designer.cs

     文件      10271  2008-06-17 16:57  Backup\PictureManage\frmSlide.resx

     文件       8261  2013-05-11 17:51  Backup\PictureManage\frmSpecialEfficacy.cs

     文件       9002  2008-06-18 09:23  Backup\PictureManage\frmSpecialEfficacy.Designer.cs

     文件       8296  2008-06-18 09:23  Backup\PictureManage\frmSpecialEfficacy.resx

     文件       4817  2013-05-11 17:50  Backup\PictureManage\frmWater.cs

     文件      11389  2013-05-11 11:32  Backup\PictureManage\frmWater.Designer.cs

     文件      11331  2008-08-05 15:46  Backup\PictureManage\frmWater.resx

     文件       2862  2008-06-17 14:13  Backup\PictureManage\ImageFolder\上.ico

     文件       2862  2008-06-17 14:13  Backup\PictureManage\ImageFolder\下.ico

     文件       1504  2008-06-17 16:52  Backup\PictureManage\ImageFolder\保存.png

     文件       2862  2008-06-18 09:22  Backup\PictureManage\ImageFolder\保存1.ico

     文件       1309  2008-06-17 16:52  Backup\PictureManage\ImageFolder\保存2.png

............此处省略123个文件信息