Asp.net 文件上传类(取得文件后缀名,保存文件,加入文字水印)

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.drawing;
using system.io;
using system.drawing.imaging;

namespace ec
{
/// <summary>
/// 上传类
/// </summary>
public class uploadobj
{

public uploadobj()
{
//
// todo: 在此处添加构造函数逻辑
//
}
/// <summary>
/// 允许文件上传的类型枚举
/// </summary>
public enum filetype
{
jpg,gif,bmp,png
}

#region 取得文件后缀
/// <summary>
/// 取得文件后缀
/// </summary>
/// <param name="filename">文件名称</param>
/// <returns></returns>
public static string getfileextends(string filename)
{
string ext = null;
if (filename.indexof('.') > 0)
{
string[] fs = filename.split('.');
ext = fs[fs.length - 1];
}
return ext;
}
#endregion

#region 检测文件是否合法
/// <summary>
/// 检测上传文件是否合法
/// </summary>
/// <param name="fileextends">文件后缀名</param>
/// <returns></returns>
public static bool checkfileextends(string fileextends)
{
bool status = false;
fileextends = fileextends.tolower();
string[] fe = enum.getnames(typeof(filetype));
for (int i = 0; i < fe.length; i++)
{
if (fe[i].tolower() == fileextends)
{
status = true;
break;
}
}
return status;
}
#endregion

#region 保存文件
/// <summary>
/// 保存文件
/// </summary>
/// <param name="fpath">全路径,server.mappath()</param>
/// <param name="myfileupload">上传控件</param>
/// <returns></returns>
public static string photosave(string fpath,fileupload myfileupload)
{
string s = "";
string fileextends = "";
string filename = myfileupload.filename;
if (filename != "")
{
//取得文件后缀
fileextends = ec.uploadobj.getfileextends(filename);
if (!ec.uploadobj.checkfileextends(fileextends))
{
ec.messageobject.showpre("上传文件类型不合法");
}
random rd = new random();
s = ec.randomobject.daterndname(rd) + "." + fileextends;
string file = fpath + "\\" + s;
try
{
myfileupload.saveas(file);
}
catch (exception ee)
{
throw new exception(ee.tostring());
}
}
return s;
}

#endregion

#region 加入文字水印

/// <summary>
/// 加入文字水印
/// </summary>
/// <param name="filename">文件名称路径(全路径)</param>
/// <param name="text">文件</param>
public void addtexttoimg(string filename, string text)
{
if (!file.exists(filename))
{
throw new filenotfoundexception("文件不存在");
}
if (text == string.empty)
{
return;
}
//判断文件类型是否为图像类型

system.drawing.image image = system.drawing.image.fromfile(filename);
bitmap bitmap = new bitmap(image, image.width, image.height);
graphics g = graphics.fromimage(bitmap);
float fontsize = 12.0f;//字体大小
float textwidth = text.length * fontsize;//文本的长度
//下面定义一个矩形区域,以后在这个矩形里面画上白底黑字
float rectx = 0;
float recty = 0;
float rectwidth = text.length * (fontsize + 8);
float rectheight = fontsize + 8;
//声明矩形域
rectanglef textarea = new rectanglef(rectx, recty, rectwidth, rectheight);
font font = new font("宋体", fontsize);//定义字体
brush whitebrush = new solidbrush(color.white);//白笔刷,画文字用
brush blackbrush = new solidbrush(color.black);//黑笔刷，画背景用
g.fillrectangle(blackbrush, rectx, recty, rectwidth, rectheight);
g.drawstring(text, font, whitebrush, textarea);
memorystream ms = new memorystream();
bitmap.save(ms, imageformat.jpeg);
//输出处理后的图像，这里为了演示方便，我将图片显示在页面中了
//response.clear();
//response.contenttype = "image/jpeg";
//response.binarywrite(ms.toarray());
g.dispose();
bitmap.dispose();
image.dispose();
}
#endregion
}
}