网页ASPX有一个TextBox，另一个ASCX有一个ImageButton，用户点一点这个铵钮，把用户在TextBox输入的文字创建为一个图片，ASCX的ImageButton的ImageUrl重新指向这刚产生的图片。
为了传值，写一个接口，返回aspx的TextBox函数：
复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI.WebControls;
/// <summary>
/// Summary description for Itransmitable
/// </summary>
namespace Insus.NET
{
public interface Itransmitable
{
TextBox GetTextBoxControl();
}
}
A.aspx.cs，并实现接口。
复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using Insus.NET;
public partial class A : System.Web.UI.Page,Itransmitable
{
protected void Page_Load(object sender, EventArgs e)
{
}
public TextBox GetTextBoxControl()
{
return this.tbHid;
}
}
A.aspx，把用户控件B.ascx接入页面。
复制代码 代码如下:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="A.aspx.cs" Inherits="A" %>
<%@ Register src="B.ascx" tagname="B" tagprefix="uc1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="tbHid" runat="server" />
<uc1:B ID="B1" runat="server" />
</div>
</form>
</body>
</html>
B.ascx:
复制代码 代码如下:
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="B.ascx.cs" Inherits="B" %>
<asp:ImageButton runat="server" ID="imgBmp" OnClick="imgBmp_Click" BorderWidth="1" />
B.ascx.cs:
复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing.Text;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Insus.NET;
public partial class B : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
this.imgBmp.ImageUrl = GetImagePath("Insus.NET"); //默认值。
}
protected void imgBmp_Click(object sender, ImageClickEventArgs e)
{
Itransmitable textbox = (Itransmitable)this.Page; //把page转换为接口。
this.imgBmp.ImageUrl = GetImagePath(textbox.GetTextBoxControl().Text.Trim());
}
//创建图片
private string GetImagePath(string _text)
{
Bitmap bitmap = new Bitmap(1, 1);
Font font = new Font("Arial", 25, FontStyle.Regular, GraphicsUnit.Pixel);
Graphics graphics = Graphics.FromImage(bitmap);
int width = (int)graphics.MeasureString(_text, font).Width;
int height = (int)graphics.MeasureString(_text, font).Height;
bitmap = new Bitmap(bitmap, new Size(width, height));
graphics = Graphics.FromImage(bitmap);
graphics.Clear(Color.White);
graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.TextRenderingHint = TextRenderingHint.AntiAlias;
graphics.DrawString(_text, font, new SolidBrush(Color.FromArgb(0, 0, 0)), 0, 0);
graphics.Flush();
graphics.Dispose();
string fileName = Path.GetFileNameWithoutExtension(Path.GetRandomFileName()) + ".jpg";
bitmap.Save(Server.MapPath("~/ImageLib/") + fileName, ImageFormat.Jpeg);
return "~/ImageLib/" + fileName;
}
}
运行效果： 
Demo code download(.NET 4.5)