图片上传加水印验证码

文件上传：

一、上传到硬盘文件夹

第一步：准备好文件及路径：
//把之前在客户端的文件名给取出来
string fileName = FileUpload1.FileName;

//防止文件重名
fileName = DateTime.Now.ToString("yyyyMMddhhmmssms") + fileName;

//把相对路径转化为绝对路径
string path = Server.MapPath("uploads/" + fileName);

第二步：执行上传：
//上传
FileUpload1.SaveAs(path);   //参数必须根路径

int index = 0;
foreach (Control ctrl in form1.Controls)
{
if (ctrl is FileUpload)
{
index++;
//取得每个上传控件
FileUpload upload = ctrl as FileUpload;
//上传控件中选上文件了
if (upload.HasFile)
{
//做文件路径出来
string path = Server.MapPath("uploads/" + DateTime.Now.ToString("yyyyMMddhhmmss") + index.ToString("00") + upload.FileName);

//上传
upload.SaveAs(path);
}
}
}

二、上传到数据库Image字段：

上传图片加水印：

//一、从上传数据中，转化成图片对象。
Stream s = FileUpload1.FileContent;
System.Drawing.Image img = System.Drawing.Image.FromStream(s);

//二、对图片对象进行画水印
//1.造笔
SolidBrush brush = new SolidBrush(Color.Yellow);
//2.造字体
Font font = new Font("Comic Sans MS", 18);
//3.找到图像绘图区域
Graphics g = Graphics.FromImage(img);
g.DrawString("http://www.itNBA.com", font, brush, 0, 0);

//三、图片对象另存到硬盘上去
string fileName = FileUpload1.FileName;
string path = Server.MapPath("uploads/" + fileName);
img.Save(path);

验证码

public partial class 验证码 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
fillYZM();
}
}
private void fillYZM() {
Bitmap img = new Bitmap(80,30);
SolidBrush bi = new SolidBrush(Color.Black);
Font font = new Font("新宋体", 24);
Graphics g = Graphics.FromImage(img);
g.FillRectangle(bi, 0, 0, img.Width, img.Height);
bi.Color = Color.White;

g.DrawString(Get(), font, bi, 0, 0);
string  path = Server.MapPath("temp.jpg");
img.Save(path);

Image1.ImageUrl = "temp.jpg";
}
private string Get()
{
string s="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
Random rand = new Random();
string yzm = "";
for (int i = 0; i < 4; i++)
{
int st=rand.Next(s.Length);
yzm += s.Substring(st, 1);
}
Session["yzm"] = yzm;
return yzm;

}
protected void Button1_Click(object sender, EventArgs e)
{
if (TextBox1.Text.Equals(Session["yzm"].ToString()))
{
Literal1.Text = "<script>alert('验证码输入正确！');</script>";
}
else
{
Literal1.Text = "<script>alert('验证码输入不正确！');</script>";
}
}

protected void Image1_Init(object sender, EventArgs e)
{

}

protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
fillYZM();
}
}