using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;

/// <summary>
/// 圖片處理類
/// 1、生成縮略圖片或按照比例改變圖片的大小和畫質
/// 2、將生成的縮略圖放到指定的目錄下
/// </summary>
public class ImageClass
{
public System.Drawing.Image ResourceImage;
private int ImageWidth;
private int ImageHeight;

public string ErrMessage;

/// <summary>
/// 類的構造函數
/// </summary>
/// <param name="ImageFileName">圖片文件的全路徑名稱</param>
public ImageClass(string ImageFileName)
{
ResourceImage = System.Drawing.Image.FromFile(ImageFileName);
ErrMessage = "";
}

public bool ThumbnailCallback()
{
return false;
}

/// <summary>
/// 生成縮略圖重載方法1，返回縮略圖的Image對象
/// </summary>
/// <param name="Width">縮略圖的寬度</param>
/// <param name="Height">縮略圖的高度</param>
/// <returns>縮略圖的Image對象</returns>
public System.Drawing.Image GetReducedImage(int Width, int Height)
{
try
{
System.Drawing.Image ReducedImage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);

ReducedImage = ResourceImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);

return ReducedImage;
}
catch (Exception e)
{
ErrMessage = e.Message;
return null;
}
}

/// <summary>
/// 生成縮略圖重載方法2，將縮略圖文件保存到指定的路徑
/// </summary>
/// <param name="Width">縮略圖的寬度</param>
/// <param name="Height">縮略圖的高度</param>
/// <param name="targetFilePath">縮略圖保存的全文件名，(帶路徑)，參數格式：D:Images ilename.jpg</param>
/// <returns>成功返回true，否則返回false</returns>
public bool GetReducedImage(int Width, int Height, string targetFilePath)
{
try
{
System.Drawing.Image ReducedImage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);

ReducedImage = ResourceImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);

ReducedImage.Dispose();

return true;
}
catch (Exception e)
{
ErrMessage = e.Message;
return false;
}
}

/// <summary>
/// 生成縮略圖重載方法3，返回縮略圖的Image對象
/// </summary>
/// <param name="Percent">縮略圖的寬度百分比 如：需要百分之80，就填0.8</param>
/// <returns>縮略圖的Image對象</returns>
public System.Drawing.Image GetReducedImage(double Percent)
{
try
{
System.Drawing.Image ReducedImage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);

ImageWidth = Convert.ToInt32(ResourceImage.Width * Percent);
ImageHeight = Convert.ToInt32(ResourceImage.Width * Percent);

ReducedImage = ResourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);

return ReducedImage;
}
catch (Exception e)
{
ErrMessage = e.Message;
return null;
}
}

/// <summary>
/// 生成縮略圖重載方法4，返回縮略圖的Image對象
/// </summary>
/// <param name="Percent">縮略圖的寬度百分比 如：需要百分之80，就填0.8</param>
/// <param name="targetFilePath">縮略圖保存的全文件名，(帶路徑)，參數格式：D:Images ilename.jpg</param>
/// <returns>成功返回true,否則返回false</returns>
public bool GetReducedImage(double Percent, string targetFilePath)
{
try
{
System.Drawing.Image ReducedImage;

System.Drawing.Image.GetThumbnailImageAbort callb = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);

ImageWidth = Convert.ToInt32(ResourceImage.Width * Percent);
ImageHeight = Convert.ToInt32(ResourceImage.Width * Percent);

ReducedImage = ResourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);

ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);

ReducedImage.Dispose();

return true;
}
catch (Exception e)
{
ErrMessage = e.Message;
return false;
}
}
}