近来有用户反映系统老是重复添加记录,一查,原因是用户在提交数据的时候,浏览器反应较慢,用户误以为程序停止,于是再次点击提交按钮,于是问题出现.
于是想到一种办法,在用户提交数据之后,当前网页最顶端显示一个透明的大小和当前浏览器客户区域同等的DIV,提示用户当前操作正在进行. 如此,用户会看到数据执行过程,就不会再次提交.
时间仓促,代码公布如下,有几处属性需要添加设计师支持. 来日有时间再完善.
Code
1
using System;
2using System.Collections.Generic;
3using System.ComponentModel;
4using System.Linq;
5using System.Text;
6using System.Web;
7using System.Web.UI;
8using System.Web.UI.WebControls;
9using System.Drawing;
10using System.Security.Permissions;
11namespace Loading
12
{
13
[ToolboxData("<{0}:DongLoading runat=server></{0}:DongLoading>")]
14 [Localizable(true)]
15 public class DongLoading : WebControl
16
{
17 private string imagePath = "1";
18 private string backColor = "AliceBlue";
19 private string targetControlID = string.Empty;
20 //private Color dongBorderColor;
21
22 [Category("DongUI"), TypeConverter(typeof(WebColorConverter)), DefaultValue(typeof(Color), ""), NotifyParentProperty(true)]
23 public Color DongBorderColor
24 {
25 get
26 {
27 return (Color)this.ViewState["DongBorderColor"];
28
}
29 set
30 {
31 this.ViewState["DongBorderColor"] = value;
32 }
33 }
34
35
36
37 Property#region Property
38 [Category("DongUI"), Description("指定做为进度提示的背景透明图片的路径"),Browsable(true)]
39 public string ImagePath
40 {
41 get { return this.imagePath; }
42 set
43 {
44 imagePath = value;
45 }
46 }
47
48 [Category("DongUI")]
49 [Description("指定背景颜色")]
50 [Browsable(true)]
51 public string BackColor
52 {
53 get { return this.backColor; }
54 set
55 {
56 backColor = value;
57 }
58 }
59
60 [Category("DongUI")]
61 [Description("指定目标控件")]
62 [Browsable(true), TypeConverter(typeof(ControlIDConverter)), DefaultValue(typeof(Button), null)]
63 public string TargetControlID
64 {
65 get { return this.ViewState["TargetControlID"].ToString(); }
66 set
67 {
68 ViewState["TargetControlID"] = value;
69 }
70 }
71 #endregion
72
73 override#region override
74 /**//// <summary>
75 /// Renders the contents.
76 /// </summary>
77 /// <param name="output">The output.</param>
78 protected override void RenderContents(HtmlTextWriter output)
79 {
80 // 隐藏透明面板
81 output.Write("<script> window.document.all." + this.ClientID + ".style.display=\"none\";</script>");
82 }
83
84 /**//// <summary>
85 /// 将控件的 HTML 开始标记呈现到指定的编写器中。此方法主要由控件开发人员使用。
86 /// </summary>
87 /// <param name="writer"><see cref="T:System.Web.UI.HtmlTextWriter"/>，表示要在客户端呈现 HTML 内容的输出流。</param>
88 public override void RenderBeginTag(HtmlTextWriter writer)
89 {
90 string color = DongBorderColor.IsNamedColor == true ? DongBorderColor.Name : "#" + DongBorderColor.Name;
91 string html = "<div id=\"" + this.ClientID + "\" oncontextmenu=\"return false;\" style=\" left: 0;top: 0; position: absolute; width: expression( window.document.documentElement.offsetWidth );" +
92 " height: expression( window.document.documentElement.clientHeight > window.document.documentElement.scrollHeight ? window.document.documentElement.clientHeight : window.document.documentElement.scrollHeight ); " +
93 " z-index: 888; filter: progid:DXImageTransform.Microsoft.Alpha(opacity=80); display: inline; background-color: " + color + "\">";
94 html += " <img style=\" position: absolute;left: expression( document.documentElement.clientWidth / 2 - this.clientWidth / 2 ); top: expression( document.documentElement.clientHeight / 2 - this.clientHeight / 2 + document.documentElement.scrollTop ); \" src=\"" + ImagePath + "\">";
95 writer.Write(html);
96 }
97
98 /**//// <summary>
99 /// 将控件的 HTML 结束标记呈现到指定的编写器中。此方法主要由控件开发人员使用。
100 /// </summary>
101 /// <param name="writer"><see cref="T:System.Web.UI.HtmlTextWriter"/>，表示要在客户端呈现 HTML 内容的输出流。</param>
102 public override void RenderEndTag(HtmlTextWriter writer)
103 {
104 if (Page != null)
105 {
106 string js = "window.document.all[\'" + this.ClientID + "\'].style.display=\'inline\'";
107 Button bt = this.Page.FindControl(TargetControlID) as Button;
108 bt.Attributes.Add("onclick", js);
109 }
110 writer.Write("</div>");
111 }
112 #endregion
113 }
114
}
115
效果:
1 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Loading.aspx.cs" Inherits="WebApplication1.Loading" %>
2 <%@ Register Assembly="Loading" Namespace="Loading" TagPrefix="cc1" %>
3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4 <html xmlns="http://www.w3.org/1999/xhtml">
5 <head runat="server">
6 <title>无标题页</title>
7 </head>
8 <body>
9 <form id="form1" runat="server">
10 <div style="height: 1316px">
11 <cc1:DongLoading ID="DongLoading1" runat="server" BackColor="Aliceblue" ImagePath="hi.gif"
12 TargetControlID="Button1" DongBorderColor="AliceBlue" />
13 <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
14 <div style="position:absolute; width:300px; height:1300px; border: solid 2px blue;"></div>
15 </div>
16 </form>
17 </body>
18 </html>
