在开发时如果要使用多个图片按钮时，我们经常必须为每个按钮制作一个图片（如：新增，修改，删除
等，其实只是文字不一样而已，我们却必须制作3个图片，一句话麻烦），如果能开发一图片按钮控件，
实现只须更改文字就可以生成按钮，那就好了。以下是实现方式（采用将图片分割成三部分进行实现）
/// <summary>
/// 图片按钮控件
/// </summary>
public class Buttoner : Button
{
//
// 常量
//
private const string HTML1 = "<TABLE ID=\"";
private const string HTML3 = "\" HEIGHT=\"";
private const string HTML4 = "\" BORDER=\"0\" CELLSPACING=\"0\" CELLPADDING=\"0\"";
private const string HTML5 = " STYLE=\"cursor:hand\" onclick=\"javascript:";
private const string HTML6 = "\"";
private const string HTML7 = ">\n\t<TR>";
private const string HTML8 = "\n\t\t<TD Valign=\"middle\" Align=\"center\" WIDTH=\"";
private const string HTML9 = "\" background=\"";
private const string HTML10 = "\">";
private const string HTML11 = "</TD>";
private const string HTML12 = "\n\t</TR>\n</TABLE>";
private const string HTML13 = " disabled=\"true\"";
private const string HTML14 = " TabIndex=\"";
private const string HTML15 = " onkeydown=\"javascript:";
private const string HTML16 = " style=\"padding-top:";
private const string KEY_FORM_SUBMIT_JS = "FormSubmitJs";
//
// 变量
//
private string leftImagePath;
private string middleImagePath;
private string rightImagePath;
private Unit length;
private Unit height = 20;
private Unit width = 6;
private Unit topPadWidth = 3;
private string action = null;
private string target = null;
private bool defaultButton = false;
/// <summary>
/// 构造函数
/// </summary>
public Buttoner()
{
leftImagePath = ApplicationUrl.GetButtonImagePath("btnLeft");
middleImagePath = ApplicationUrl.GetButtonImagePath("btnMiddle");
rightImagePath = ApplicationUrl.GetButtonImagePath("btnRight");
}
/// <summary>
/// 左图片路径
/// </summary>
public string LeftImagePath
{
get
{
return leftImagePath;
}
set
{
leftImagePath = value;
}
}
/// <summary>
/// 中间图片路径
/// </summary>
public string MiddleImagePath
{
get
{
return middleImagePath;
}
set
{
middleImagePath = value;
}
}
/// <summary>
/// 右图片路径
/// </summary>
public string RightImagePath
{
get
{
return rightImagePath;
}
set
{
rightImagePath = value;
}
}
/// <summary>
/// 中间图片长度
/// </summary>
public Unit Length
{
get
{
return length;
}
set
{
length = value;
}
}
/// <summary>
/// 图片高度
/// </summary>
public override Unit Height
{
get
{
return height;
}
set
{
height = value;
}
}
/// <summary>
/// 图片宽度
/// </summary>
public override Unit Width
{
get
{
return width;
}
set
{
width = value;
}
}
/// <summary>
/// 图片距顶部宽度
/// </summary>
public Unit TopPadWidth
{
get
{
return topPadWidth;
}
set
{
topPadWidth = value;
}
}
/// <summary>
/// 提交的页面
/// </summary>
public string Action
{
get
{
return action;
}
set
{
action = value;
}
}
/// <summary>
/// Action的目标框架
/// </summary>
public string Target
{
get
{
return target;
}
set
{
target = value;
}
}
/// <summary>
/// 是否默认按钮
/// </summary>
public bool DefaultButton
{
get
{
return defaultButton;
}
set
{
defaultButton = value;
}
}
protected override void OnPreRender(EventArgs e)
{
if(this.Visible && !Page.IsClientScriptBlockRegistered(ApplicationKey.FORM_SUBMIT_JS))
{
string src = ApplicationUrl.GetJsPath("FormSubmit");
StringBuilder strBuilder = new StringBuilder();
strBuilder.Append("<script language=\"javascript\" src=\"");
strBuilder.Append(src);
strBuilder.Append("\"></script>");
if(defaultButton)
{
strBuilder.Append("\n<script language=\"javascript\" id=\"ButtonEnterSubmit\" for=\"document\" event=\"onkeydown\">\n\t");
strBuilder.Append("if(window.event.keyCode == 13)\n\t\t");
strBuilder.Append("{\n\t\t\t");
strBuilder.Append("document.getElementById('");
strBuilder.Append(this.ClientID);
strBuilder.Append("').focus();\n\t\t\t");
if(this.Enabled)
{
if(this.CausesValidation)
strBuilder.Append("if(typeof(Page_ClientValidate) != 'function' || Page_ClientValidate()) ");
if(action == null || action == string.Empty)
strBuilder.Append(Page.GetPostBackEventReference(this));
else
{
strBuilder.Append("Submit('");
strBuilder.Append(action);
strBuilder.Append("', '");
strBuilder.Append(target);
strBuilder.Append("');");
}
}
strBuilder.Append("\n\t\t}");
strBuilder.Append("\n</script>");
}
Page.RegisterClientScriptBlock(ApplicationKey.FORM_SUBMIT_JS, strBuilder.ToString());
}
}
protected override void Render(HtmlTextWriter writer)
{
if(this.Visible)
{
writer.Write(HTML1);
writer.Write(this.ClientID);
writer.Write(HTML3);
writer.Write(height);
writer.Write(HTML4);
writer.Write(HTML14);
writer.Write(this.TabIndex);
writer.Write(HTML6);
if(this.Enabled)
{
// onclick提交
writer.Write(HTML5);
writer.Write("{ document.getElementById('");
writer.Write(this.ClientID);
writer.Write("').focus(); ");
if(this.CausesValidation)
writer.Write("if(typeof(Page_ClientValidate) != 'function' || Page_ClientValidate()) ");
if(action == null || action == string.Empty)
writer.Write(Page.GetPostBackEventReference(this));
else
{
writer.Write("Submit('");
writer.Write(action);
writer.Write("', '");
writer.Write(target);
writer.Write("');");
}
writer.Write("} ");
writer.Write(HTML6);
}
else
writer.Write(HTML13);
writer.Write(HTML7);
writer.Write(HTML8);
writer.Write(width);
writer.Write(HTML9);
writer.Write(leftImagePath);
writer.Write(HTML10);
writer.Write(" ");
writer.Write(HTML11);
writer.Write(HTML8);
writer.Write(length);
writer.Write(HTML9);
writer.Write(middleImagePath);
writer.Write(HTML6);
writer.Write(HTML16);
writer.Write(topPadWidth);
writer.Write(HTML10);
writer.Write(this.Text);
writer.Write(HTML11);
writer.Write(HTML8);
writer.Write(width);
writer.Write(HTML9);
writer.Write(rightImagePath);
writer.Write(HTML10);
writer.Write(" ");
writer.Write(HTML11);
writer.Write(HTML12);
}
}
}
FormSubmit.js
// click提交
function Submit(action, target)
{
document.forms[0].action = action;
if(target != null && target.length != 0)
document.forms[0].target = target;
document.forms[0].__VIEWSTATE.disabled = true;
document.forms[0].submit();
}
// 按Enter键事件
function EnterKeyDown(id)
{
if(window.event.keyCode == 13 && window.event.srcElement.id == id)
return true;
else
return false;
}
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