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Asp.net自定义控件之单选、多选控件

本文实例为大家分享了Asp.net单选、复选框控件的具体实现代码,供大家参考,具体内容如下

将常用的jquery插件封装成控件也是个不错的选择。

先看看效果:

1.新建类库项目,创建数据源类

 [Serializable]
 public class Select2Item
 {
 public bool Selected { get; set; }

 public string Text { get; set; }

 public string Value { get; set; }

 public Select2Item() { }

 public Select2Item(string text, string value)
 {
  this.Text = text;
  this.Value = value;
 }

 public Select2Item(string text, string value, bool selected)
 {
  this.Text = text;
  this.Value = value;
  this.Selected = selected;
 }
 } 

2.创建控件类CheckList,继承与WebControl,并定义 public List<Select2Item> Items数据项属性。

3.引入脚本文件及样式文件 
a.创建脚本或样式文件,设置文件的属性-生成操作-嵌入的资源

  

b.需要在namespace上添加标记 [assembly: WebResource("命名空间.文件夹名.文件名", "mime类型")]
如:
    [assembly: WebResource("Control.Style.checklist.css", "text/css",PerformSubstitution = true)]
    [assembly: WebResource("Control.Scripts.checklist.js", "application/x-javascript")]
 

 如果css文件里面存在图片的话,同样将图片设置为嵌入的资源,在css中的写法为<%=WebResource("命名空间.文件夹名.文件名")%> 
 PerformSubstitution 表示嵌入式资源的处理过程中是否分析其他Web 资源 URL,并用到该资源的完整路径替换。
c.重写protected override void OnPreRender(EventArgs e),引入嵌入的脚本或样式文件
 if(Page!=null) Page.Header.Controls.Add(LiteralControl),将<script><link>标签放到LiteralControl中,然后将LiteralControl添加到Page.Header中,最后在页面里你就会看到引入的<script><link>标签。

 protected override void OnPreRender(EventArgs e)
 {
  if (this.Page != null)
  {
  StringBuilder sbb = new StringBuilder();
  sbb.Append(string.Format(STYLE_TEMPLATE, Page.ClientScript.GetWebResourceUrl(this.GetType(), "HandControl.Style.checklist.css")));
  sbb.Append(string.Format(SCRIPT_TEMPLATE, Page.ClientScript.GetWebResourceUrl(this.GetType(), "HandControl.Scripts.checklist.js")));

  bool hascss = false;
  LiteralControl lcc = new LiteralControl(sbb.ToString());
  lcc.ID = "lccheck";
  foreach (Control item in Page.Header.Controls)
  {
   if (item.ID == "lccheck")
   hascss = true;
  }
  if (!hascss)
   Page.Header.Controls.Add(lcc);
  }
  base.OnPreRender(e);
 } 

4.重写控件的protected override void Render(HtmlTextWriter writer)方法
这里主要是渲染控件的html,根据你的控件而定。 

 protected override void Render(HtmlTextWriter writer)
 {
  if (Items.Count > 0)
  {
  writer.Write("<div id='div" + this.ClientID + "' class='c01-tag-div' mul='" + (Multiple == true ? "1" : "0") + "'>");
  if (Multiple == false)
   writer.Write("<input name='tb" + this.ClientID + "' type='hidden' value='" + Items[0].Value + "' />");
  else
   writer.Write("<input name='tb" + this.ClientID + "' type='hidden' />");
  bool first = true;
  foreach (var item in Items)
  {
   if (Multiple == false)
   {
   if (item.Selected && first)
   {
    writer.Write("<a title='" + item.Text + "' class='c01-tag-item c01-tag-select' val='" + item.Value + "' tag='Y'>" + item.Text + "</a>");
    first = false;
   }
   else
   {
    writer.Write("<a title='" + item.Text + "' class='c01-tag-item' val='" + item.Value + "' tag='N'>" + item.Text + "</a>");
   }
   }
   else
   {
   if (item.Selected)
    writer.Write("<a title='" + item.Text + "' class='c01-tag-item c01-tag-select' val='" + item.Value + "' tag='Y'>" + item.Text + "</a>");
   else
    writer.Write("<a title='" + item.Text + "' class='c01-tag-item' val='" + item.Value + "' tag='N'>" + item.Text + "</a>");
   }
  }
  writer.Write("</div>");
  }
 } 

5.添加GetSelected方法,返回List<Select2Item>,添加GetSelectValue,返回String(多选以,号隔开)       

 public List<Select2Item> GetSelected()
 {
  if (Page != null)
  {
  var values = Page.Request.Form["tb" + this.ClientID].Split(',');
  var res = Items.Where(t => values.Contains(t.Value)).ToList();
  foreach (var item in Items)
  {
   if (res.Contains(item))
   {
   item.Selected = true;
   }
   else
   {
   item.Selected = false;
   }
  }
  return res;
  }
  else
  {
  return null;
  }
 } 
 public string GetSelectValue()
 {
  if (Page != null)
  {
  return Page.Request.Form["tb" + this.ClientID];
  }
  return "";
 } 

6.保存状态
 你需要重写两个方法protected override object SaveViewState() 、protected override void LoadViewState(object savedState),旨在将Items数据项属性保存到ViewState 

 protected override object SaveViewState()
 {
  var valuestr = Page.Request.Form["tb" + this.ClientID];
  if (!string.IsNullOrEmpty(valuestr))
  {
  var values = valuestr.Split(',');
  var temp = Items.Where(t => values.Contains(t.Value)).ToList();
  foreach (var item in temp)
  {
   item.Selected = true;
  }
  }
  return new object[] { base.SaveViewState(), Items };
 }

 protected override void LoadViewState(object savedState)
 {
  object[] vState = (object[])savedState;
  if (vState[0] != null)
  base.LoadViewState(vState[0]);
  if (vState[1] != null)
  Items = (List<Select2Item>)vState[1];
 } 

7.单选和复选的设置,在js中控制
 添加属性 
[Description("获取和设置多选"), DefaultValue(true), Browsable(true), Category("杂项")]
public bool Multiple { get; set; }
 在OnPreRender代码中你会发现Multiple属性会影响div的mul属性值,从而判断是否多选(默认多选)
 8.其它说明
private static readonly string STYLE_TEMPLATE = "<link href=\"{0}\" rel=\"stylesheet\" type=\"text/css\" />\r\n";
 private static readonly string SCRIPT_TEMPLATE = "<script type=\"text/javascript\" src=\"{0}\"></script>\r\n";

效果图:

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。