Asp.net開發之webform圖片浮水印和圖片驗證碼的實現方法_實用技巧

來源:互聯網
上載者:User

兩者都需要引入命名空間:using System.Drawing;

一、圖片浮水印

前台Photoshuiyin.aspx代碼:

<div><asp:FileUpload ID="FileUpload1" runat="server" /><asp:Button ID="Button1" runat="server" Text="上傳" /><br /><asp:Image ID="Image1" runat="server" /></div>

後台Photoshuiyin.aspx.cs代碼:

protected void Page_Load(object sender, EventArgs e){Button1.Click += Button1_Click;}void Button1_Click(object sender, EventArgs e){//1、製作畫布System.Drawing.Image img = System.Drawing.Image.FromStream(FileUpload1.FileContent);Graphics g = Graphics.FromImage(img);//浮水印樣式:畫什麼東西string a = "http://www.itnba.com";//字型、大小Font f = new Font("黑體", 30);//顏色Brush b = new SolidBrush(Color.Red);//0,0——開始畫浮水印的位置g.DrawString(a, f, b, 0, 0);//儲存路徑string path = "images/" + FileUpload1.FileName;img.Save(Server.MapPath(path));//在image控制項中展示Image1.ImageUrl = path;}

效果展示:

二、圖片驗證碼

前台Photoyanzhengma.aspx代碼:

<form id="form1" runat="server"><div>使用者名稱:<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />密碼:<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox><br />驗證碼:<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox><asp:Image ID="Image1" runat="server" ImageUrl="YZM.aspx" /><asp:Label ID="Label1" runat="server" Text="Label"></asp:Label><br /><asp:Button ID="Button1" runat="server" Text="Button" /></div></form></body></html><script type="text/javascript">var aaa = 1;document.getElementById("Image1").onclick = function () {this.setAttribute("src", "YZM.aspx?id=" + aaa);aaa++;};</script>

連結頁面“YZM.aspx”——無需前台代碼,後台代碼是:

protected void Page_Load(object sender, EventArgs e){Random r = new Random();string aaa = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";//產生畫布Bitmap img = new Bitmap(80, 30);//畫布背景色泛性組合List<Color> Clist = new List<Color>();Clist.Add(Color.Yellow);Clist.Add(Color.Green);Clist.Add(Color.Blue);Clist.Add(Color.Aqua);Clist.Add(Color.Orange);Clist.Add(Color.Pink);Graphics g = Graphics.FromImage(img);g.FillRectangle(new SolidBrush(Clist[r.Next(0, Clist.Count)]), 0, 0, 80, 30);//隨機產生顯示的驗證碼組合string str = "";for (int i = 0; i < 4; i++){str += aaa.Substring(r.Next(0, aaa.Length), 1);}Session["YZM"] = str;Font f = new Font("黑體", 20);Brush b = new SolidBrush(Color.Red);//產生g.DrawString(str, f, b, 10, 0);//添加幹擾線for (int i = 0; i < r.Next(6, 20); i++){Brush bb = new SolidBrush(Clist[r.Next(0, Clist.Count)]);Pen p = new Pen(bb, 1);g.DrawLine(p, r.Next(0, 80), r.Next(0, 30), r.Next(0, 80), r.Next(0, 30));}//儲存完成img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);Response.End();}

效果展示:

以上所述是小編給大家介紹的Asp.net開發之webform圖片浮水印和圖片驗證碼的實現方法,希望對大家有所協助,如果大家有任何疑問請給我留言,小編會及時回複大家的。在此也非常感謝大家對雲棲社區網站的支援!

相關文章

聯繫我們

該頁面正文內容均來源於網絡整理,並不代表阿里雲官方的觀點,該頁面所提到的產品和服務也與阿里云無關,如果該頁面內容對您造成了困擾,歡迎寫郵件給我們,收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容,歡迎發送郵件至: info-contact@alibabacloud.com 進行舉報並提供相關證據,工作人員會在 5 個工作天內聯絡您,一經查實,本站將立刻刪除涉嫌侵權內容。

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.