webform（十）——圖片水印和圖片驗證碼

二者都須要引入命名空間：using System.Drawing;

1、圖片水印

前臺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>

後臺Photoshuiyin.aspx.cs代碼：

protected void Page_Load(object sender, EventArgs e) { Button1.Click += Button1_Click; } void Button1_Click(object sender, EventArgs e) { //一、製做畫布
        System.Drawing.Image img = System.Drawing.Image.FromStream(FileUpload1.FileContent); Graphics g = Graphics.FromImage(img); //水印樣式：畫什麼東西
        string a = "http://www.itnba.com"; //字體、大小
        Font f = new Font("黑體", 30); //顏色
        Brush b = new SolidBrush(Color.Red); //0,0——開始畫水印的位置
        g.DrawString(a, f, b, 0, 0); //保存路徑
        string path = "images/" + FileUpload1.FileName; img.Save(Server.MapPath(path)); //在image控件中展現
        Image1.ImageUrl = path; }

效果展現：

 

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2、圖片驗證碼

前臺Photoyanzhengma.aspx代碼：

<form id="form1" runat="server">
    <div> 用戶名：<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>

連接頁面「YZM.aspx」——無需前臺代碼，後臺代碼是：

protected void Page_Load(object sender, EventArgs e) { Random r = new Random(); string aaa = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"; //生成畫布
        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); //隨機生成顯示的驗證碼組合
        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); //生成
        g.DrawString(str, f, b, 10, 0); //添加干擾線
        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)); } //保存完成
 img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); Response.End(); }

效果展現：