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使用FileUpload控件上传图片并自动生成缩略图、自动生成带文字和图片的水印图

2008-05-22 10:55 791 查看

本文借助vs2005中自带的FileUpload控件实现图片文件的上传并生成缩略图。
实现过程：选择图片上传成功后，取得已经存在服务器的文件生成缩略图，并且判断是否是图片类型的文件，这个的判断可以在程序中修改，本程序只是判断了“image/bmp”、“image/gif”、“image/pjpeg”三种类型。
代码如下：
upfile.aspx文件

@ Page Language="C#" AutoEventWireup="true" CodeFile="upfile.aspx.cs" Inherits="upfile_upfile" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<div>

<asp:FileUpload ID="FileUpload1" runat="server" />

<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="上传" /><br />

<asp:Label ID="Label1" runat="server"></asp:Label></div>

</form>

</body>

</html>

upfile.aspx.cs文件

using System;

using System.Data;

using System.Configuration;

using System.Collections;

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;

public partial class upfile_upfile : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{ }

protected void Button1_Click(object sender, EventArgs e)

{

if (FileUpload1.HasFile)

{

string fileContentType = FileUpload1.PostedFile.ContentType;

if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg")

{

string name = FileUpload1.PostedFile.FileName; // 客户端文件路径

FileInfo file = new FileInfo(name);

string fileName = file.Name; // 文件名称

string fileName_s = "s_" + file.Name; // 缩略图文件名称

string fileName_sy = "sy_" + file.Name; // 水印图文件名称（文字）

string fileName_syp = "syp_" + file.Name; // 水印图文件名称（图片）

string webFilePath = Server.MapPath("file/" + fileName); // 服务器端文件路径

string webFilePath_s = Server.MapPath("file/" + fileName_s);　　// 服务器端缩略图路径

string webFilePath_sy = Server.MapPath("file/" + fileName_sy);　// 服务器端带水印图路径(文字)

string webFilePath_syp = Server.MapPath("file/" + fileName_syp);　// 服务器端带水印图路径(图片)

string webFilePath_sypf = Server.MapPath("file/shuiyin.jpg");　// 服务器端水印图路径(图片)

if (!File.Exists(webFilePath))

{

try

{

FileUpload1.SaveAs(webFilePath); // 使用 SaveAs 方法保存文件

AddShuiYinWord(webFilePath, webFilePath_sy);

AddShuiYinPic(webFilePath, webFilePath_syp, webFilePath_sypf);

MakeThumbnail(webFilePath, webFilePath_s, 130, 130, "Cut"); // 生成缩略图方法

Label1.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + FileUpload1.PostedFile.ContentType + "，文件大小为：" + FileUpload1.PostedFile.ContentLength + "B";

}

catch (Exception ex)

{

Label1.Text = "提示：文件上传失败，失败原因：" + ex.Message;

}

else

{

Label1.Text = "提示：文件已经存在，请重命名后上传";

}

else

{

Label1.Text = "提示：文件类型不符";

}

/**//// <summary>

/// 生成缩略图

/// </summary>

/// <param name="originalImagePath">源图路径（物理路径）</param>

/// <param name="thumbnailPath">缩略图路径（物理路径）</param>

/// <param name="width">缩略图宽度</param>

/// <param name="height">缩略图高度</param>

/// <param name="mode">生成缩略图的方式</param>

public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)

{

System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

int towidth = width;

int toheight = height;

int x = 0;

int y = 0;

int ow = originalImage.Width;

int oh = originalImage.Height;

switch (mode)

{

case "HW"://指定高宽缩放（可能变形）

break;

case "W"://指定宽，高按比例

toheight = originalImage.Height * width / originalImage.Width;

break;

case "H"://指定高，宽按比例

towidth = originalImage.Width * height / originalImage.Height;

break;

case "Cut"://指定高宽裁减（不变形）

if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)

{

oh = originalImage.Height;

ow = originalImage.Height * towidth / toheight;

y = 0;

x = (originalImage.Width - ow) / 2;

}

else

{

ow = originalImage.Width;

oh = originalImage.Width * height / towidth;

x = 0;

y = (originalImage.Height - oh) / 2;

}

break;

default:

break;

}

//新建一个bmp图片

System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

//新建一个画板

System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

//设置高质量插值法

g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

//设置高质量,低速度呈现平滑程度

g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

//清空画布并以透明背景色填充

g.Clear(System.Drawing.Color.Transparent);

//在指定位置并且按指定大小绘制原图片的指定部分

g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight),

new System.Drawing.Rectangle(x, y, ow, oh),

System.Drawing.GraphicsUnit.Pixel);

try

{

//以jpg格式保存缩略图

bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);

}

catch (System.Exception e)

{

throw e;

}

finally

{

originalImage.Dispose();

bitmap.Dispose();

g.Dispose();

}

/**//// <summary>

/// 在图片上增加文字水印

/// </summary>

/// <param name="Path">原服务器图片路径</param>

/// <param name="Path_sy">生成的带文字水印的图片路径</param>

protected void AddShuiYinWord(string Path, string Path_sy)

{

string addText = "测试水印";

System.Drawing.Image image = System.Drawing.Image.FromFile(Path);

System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);

g.DrawImage(image, 0, 0, image.Width, image.Height);

System.Drawing.Font f = new System.Drawing.Font("Verdana", 16);

System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Blue);

g.DrawString(addText, f, b, 15, 15);

g.Dispose();

image.Save(Path_sy);

image.Dispose();

}

/**//// <summary>

/// 在图片上生成图片水印

/// </summary>

/// <param name="Path">原服务器图片路径</param>

/// <param name="Path_syp">生成的带图片水印的图片路径</param>

/// <param name="Path_sypf">水印图片路径</param>

protected void AddShuiYinPic(string Path, string Path_syp, string Path_sypf)

{

System.Drawing.Image image = System.Drawing.Image.FromFile(Path);

System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf);

System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);

g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width,copyImage.Height, System.Drawing.GraphicsUnit.Pixel);

g.Dispose();

image.Save(Path_syp);

image.Dispose();

}

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