OnPreRender事件常见用法

1) 加入脚本

1  protected override void OnPreRender(EventArgs e)
2   {
3      base.OnPreRender(e);
4      this.Page.RegisterClientScriptBlock("InsertText", this.RenderScript());
5      this.Page.RegisterOnSubmitStatement("StorePostBody", "StorePostBody();");
6   }

2) 设定标题

 1  protected override void OnPreRender(EventArgs e)
 2   {
 3      if(_mainTitle != null)
 4         _mainTitle.Text = ResourceManager.GetString(Title);
 5 
 6      if(_subTitle != null)
 7         _subTitle.Text = ResourceManager.GetString(SubTitle);
 8 
 9      base.OnPreRender (e);
10  }

3) 设定按钮客户端事件

1  protected override void OnPreRender(EventArgs e)
2   {
3      Submit.Attributes.Add("onclick", "return SubmitSendToFriend('" + From.ClientID + "', '" + To.ClientID + "');");
4   }

4) 设定控件的状态

 1 protected override void OnPreRender(System.EventArgs e)
 2   {
 3     if(replyButton.Visible == false)
 4       ((Literal)FindControl("Sep1")).Visible = false;    
 5 
 6     if(threadSubButton.Visible == false)
 7       ((Literal)FindControl("Sep3")).Visible = false;
 8 
 9     if(rateButton.Visible == false)
10       ((Literal)FindControl("Sep2")).Visible = false;
11 
12     base.OnPreRender (e);
13  }

5) 加入脚本块

 1 protected override void OnPreRender(EventArgs e)
 2   {
 3      base.OnPreRender (e);
 4      StringBuilder sb = new StringBuilder();
 5      sb.Append(" ");
 6      sb.Append("  function ToggleRateMenu() {");
 7      sb.Append("    rateMenu = document.getElementById('RateMenu');");
 8      sb.Append("    rateButton = document.getElementById('RateButton');");
 9      sb.Append("");
10      sb.Append("    rateMenu.style.left = getposOffset(rateButton, /"left/");");
11      sb.Append("    rateMenu.style.top = getposOffset(rateButton, /"top/") + rateButton.offsetHeight;");
12      sb.Append("");
13      sb.Append("    if (rateMenu.style.visibility == /"hidden/") {");
14      sb.Append("      rateMenu.style.visibility = /"visible/";");
15      sb.Append("      rateMenu.style.display = 'block';");
16      sb.Append("    } else {");
17      sb.Append("      rateMenu.style.visibility = /"hidden/";");
18      sb.Append("      rateMenu.style.display = 'none';");
19      sb.Append("    }");
20      sb.Append("  }");
21      sb.Append("  ");
22      sb.Append("  function getposOffset(what, offsettype){");
23      sb.Append("  var totaloffset=(offsettype==/"left/")? what.offsetLeft : what.offsetTop;");
24      sb.Append("  var parentEl=what.offsetParent;");
25      sb.Append("  while (parentEl!=null){");
26      sb.Append("    totaloffset=(offsettype==/"left/")? totaloffset+parentEl.offsetLeft : totaloffset+parentEl.offsetTop;");
27      sb.Append("    parentEl=parentEl.offsetParent;");
28      sb.Append("  }");
29      sb.Append("  return totaloffset;");
30      sb.Append("}");
31      sb.Append(" ");
32      Page.RegisterClientScriptBlock("RatePost",sb.ToString());
33   }