ASP.NET图片上传，自动缩放，自动居中代码,Asp.Net代码库,德仔网

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【Asp.Net】 ASP.NET图片上传，自动缩放，自动居中
作者:Dezai.CN / 发布于2012/11/23/ 720
图片上传
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.Security.Cryptography;
using System.Text;
using System.IO;
using System.Drawing;
using System.Threading;

public class _PhotoHandler
{
    public _PhotoHandler()
    {
        //调用方法!
        //PhotoHandler.Upload_Server(FileUpload1, "../../Upload", "Upload", 400, 400, true, System.Drawing.Color.White);
    }

    #region 生成缩略图
    /// <summary>
    /// 生成缩略图
    /// </summary>
    /// <param name="orginalImagePat">原图片地址</param>
    /// <param name="thumNailPath">缩略图地址</param>
    /// <param name="width">缩略图宽度</param>
    /// <param name="height">缩略图高度</param>
    /// <param name="model">生成缩略的模式</param>
    public static void MakeThumNail(string originalImagePath, string thumNailPath, int width, int height, int oldW, int oldH, System.Drawing.Color color)
    {
        System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
        int thumWidth = width;      //缩略图的宽度
        int thumHeight = height;    //缩略图的高度
        int originalWidth = originalImage.Width;    //原始图片的宽度
        int originalHeight = originalImage.Height;  //原始图片的高度
        //新建一个bmp图片
        System.Drawing.Image bitmap = new System.Drawing.Bitmap(oldW, oldH);
        //新建一个画板
        System.Drawing.Graphics graphic = System.Drawing.Graphics.FromImage(bitmap);
        //设置高质量查值法
        graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
        //设置高质量，低速度呈现平滑程度
        graphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
        //清空画布并填充背景色
        graphic.Clear(color);
        //在指定位置并且按指定大小绘制原图片的指定部分
        int x = 0;
        int y = 0;
        if (oldW == thumWidth && oldH > thumHeight)
        {
            y = (oldH - thumHeight) / 2;
        }
        else if (oldH == thumHeight && oldW > thumWidth)
        {
            x = (oldW - thumWidth) / 2;
        }
        if (oldW > thumWidth && oldH > thumHeight)
        {
            x = (oldW - thumWidth) / 2;
            y = (oldH - thumHeight) / 2;
        }
        graphic.DrawImage(originalImage, new System.Drawing.Rectangle(x, y, thumWidth, thumHeight), new System.Drawing.Rectangle(0, 0, originalWidth, originalHeight), System.Drawing.GraphicsUnit.Pixel);
        try
        {
            bitmap.Save(thumNailPath, System.Drawing.Imaging.ImageFormat.Png);
        }
        catch (Exception ex)
        {

            throw ex;
        }
        finally
        {
            originalImage.Dispose();
            bitmap.Dispose();
            graphic.Dispose();
        }
    }
    #endregion

    #region 在图片上添加文字水印
    /// <summary>
    /// 在图片上添加文字水印
    /// </summary>
    /// <param name="path">要添加水印的图片路径</param>
    /// <param name="syPath">生成的水印图片存放的位置</param>
    /// <param name="syWord">图片上显示文本</param>
    public static void AddWaterWord(string path, string syPath, string syWord)
    {
        System.Drawing.Image image = System.Drawing.Image.FromFile(path);

        //新建一个画板
        System.Drawing.Graphics graphic = System.Drawing.Graphics.FromImage(image);
        graphic.DrawImage(image, 0, 0, image.Width, image.Height);

        //设置字体
        System.Drawing.Font f = new System.Drawing.Font("Verdana", 30);

        //设置字体颜色
        System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Gray);

        graphic.DrawString(syWord, f, b, 20, 120);
        graphic.Dispose();

        //保存文字水印图片
        image.Save(syPath);
        image.Dispose();

    }
    #endregion

    #region 在图片上添加图片水印
    /// <summary>
    /// 在图片上添加图片水印
    /// </summary>
    /// <param name="path">原服务器上的图片路径</param>
    /// <param name="syPicPath">水印图片的路径</param>
    /// <param name="waterPicPath">生成的水印图片存放路径</param>
    public static void AddWaterPic(string path, string syPicPath, string waterPicPath)
    {
        System.Drawing.Image image = System.Drawing.Image.FromFile(path);
        System.Drawing.Image waterImage = System.Drawing.Image.FromFile(syPicPath);
        System.Drawing.Graphics graphic = System.Drawing.Graphics.FromImage(image);
        graphic.DrawImage(waterImage, new System.Drawing.Rectangle(image.Width - waterImage.Width, image.Height - waterImage.Height, waterImage.Width, waterImage.Height), 0, 0, waterImage.Width, waterImage.Height, System.Drawing.GraphicsUnit.Pixel);
        graphic.Dispose();

        image.Save(waterPicPath);
        image.Dispose();
    }
    #endregion

    #region 处理图片的缩略图
    /// <summary>
    /// 处理图片的缩略图
    /// </summary>
    /// <param name="type">图片类型,例如：jpg,gif,gpeg,png,bmp...</param>
    /// <param name="path">保存之后的图片路径</param>
    /// <param name="w">图片处理的宽度</param>
    /// <param name="h">图片处理的高度</param>
    /// <param name="OldPath">图片原始路径,例如：../../Upload</param>
    /// <param name="NewPath">图片保存路径,例如：Upload</param>
    /// <param name="delete">图片上传完成是否删除原始图片</param>
    /// <param name="color">图片大小不足时采用什么背景颜色填充</param>
    /// <returns>返回处理好的图片路径</returns>
    public static string PhotoHelper(string type, string path, int w, int h, string OldPath, string NewPath, bool delete, System.Drawing.Color color)
    {
        System.IO.FileInfo fileInfo = new System.IO.FileInfo(path);
        string fileName = fileInfo.Name;
        string sFileName = "0" + fileName;
        string fileType = type.ToLower();
        if (fileType == "bmp" || type == "jpeg" || fileType == "gif" || fileType == "jpg" || type == "png")
        {
            string sFilePath = HttpContext.Current.Server.MapPath(OldPath + "/" + sFileName);
            if (System.IO.File.Exists(path))
            {
                System.Drawing.Bitmap img = new System.Drawing.Bitmap(path);
                int width = img.Width;
                int height = img.Height;
                int NewWidth = w;
                int NewHeight = h;
                if (width > w || height > h)
                {
                    #region 将图片等比例缩放
                    double proportion_width = 0;//宽度比例
                    double proportion_height = 0;//高度比例
                    proportion_width = double.Parse(width.ToString()) / double.Parse(w.ToString());
                    proportion_height = double.Parse(height.ToString()) / double.Parse(h.ToString());
                    if (proportion_width > proportion_height)
                    {
                        double h_new = double.Parse(height.ToString()) / proportion_width;
                        string[] temp = h_new.ToString().Split('.');
                        NewHeight = int.Parse(temp[0]);
                    }
                    else
                    {
                        double w_new = double.Parse(width.ToString()) / proportion_height;
                        string[] temp = w_new.ToString().Split('.');
                        NewWidth = int.Parse(temp[0]);
                    }
                    #endregion
                    MakeThumNail(path, sFilePath, NewWidth, NewHeight, w, h, color);//返回缩放后的图片
                    if (delete == true && File.Exists(path) == true)
                    {
                        img.Dispose();
                        Thread.Sleep(30);
                        File.Delete(path);
                    }
                }
                else
                {
                    MakeThumNail(path, sFilePath, width, height, w, h, color);//返回缩放后的图片
                    if (delete == true && File.Exists(path) == true)
                    {
                        img.Dispose();
                        Thread.Sleep(30);
                        File.Delete(path);
                    }
                }
            }
            else
            {
                return "0";//文件不存在
            }
        }
        else
        {
            return "1";//文件格式不正确
        }
        return NewPath + "/" + sFileName;
    }
    #endregion

    #region 图片处理|服务器控件上传
    /// <summary>
    /// 图片处理|服务器控件上传
    /// </summary>
    /// <param name="file">FileUpload控件名</param>
    /// <param name="OldPath">图片原始路径,例如：../../Upload</param>
    /// <param name="NewPath">图片保存路径,例如：Upload</param>
    /// <param name="width">图片缩放之后的宽度</param>
    /// <param name="height">图片缩放之后的高度</param>
    /// <param name="delete">图片上传完成是否删除原始图片</param>
    /// <param name="color">图片大小不足时采用什么背景颜色填充</param>
    /// <returns>返回处理好的图片路径</returns>
    public static string Upload_Server(FileUpload file, string OldPath, string NewPath, int width, int height, bool delete, System.Drawing.Color color)
    {
        string Action = "";
        if (file.PostedFile.FileName != null && file.PostedFile.FileName.ToString() != "")
        {
            string name = file.PostedFile.FileName.ToString();
            string type = name.Substring(name.LastIndexOf(".") + 1).ToLower();
            string[] temp = name.Split('\\');
            string path = temp[temp.Length - 1];
            int bytes = file.PostedFile.ContentLength;
            if (type == "jpg" || type == "gif" || type == "jpeg" || type == "png" || type == "bmp")
            {
                if (bytes > 1024 * 1024 * 2)
                {
                    Action = "2";//图片大与2M了
                }
                else
                {
                    path = DateTime.Now.ToString("yyyyMMddHHmmssfff") + "." + type;
                    System.Web.HttpServerUtility server = System.Web.HttpContext.Current.Server;
                    string PhotoUrl = server.MapPath(OldPath + "/" + path);
                    file.SaveAs(PhotoUrl);
                    Action = PhotoHelper(type, PhotoUrl, width, height, OldPath, NewPath, delete, color);
                }
            }
            else
            {
                Action = "1";//图片格式不正确
            }
        }
        return Action;
    }
    #endregion
}
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