关于理解的一些问题 [英] some problem about understanding

问题描述

<pre lang="xml"><asp:DataList ID="SearchResultList" runat="server" Width="100%" RepeatColumns="9" OnSelectedIndexChanged="SearchResultList_SelectedIndexChanged">
               <ItemTemplate>
                  <table border="0" cellpadding="2" cellspacing="2" align="center" style="background-color: #f5f5f5">
                      <tr>
                          <td align="center" valign="top">
                              <a href=''<%#getHREF(Container.DataItem)%>''>
                                  <img src=''<%#getSRC(Container.DataItem) %>'' align="middle" border="0" width="80px">
                              </a>
                          </td>
                      </tr>
                  </table>
              </ItemTemplate>
              </asp:DataList>

if (!Page.IsPostBack)
      {
          GetSearchResult(Request.QueryString["searchText"].ToString());
      }
  }
  public void GetSearchResult(string searchText)
  {
      string GetSearchResult = "Select * FROM [User] where Name like ''" + searchText+ "%''";
      dt = dbClass.ConnectDataBaseReturnDT(GetSearchResult);
      //if (dt.Rows.Count > 0)
      //{
          SearchResultList.DataSource = dt;
          SearchResultList.DataBind();
      //}
  }
  public string getHREF(object sURL)
  {
      DataRowView dRView = (DataRowView)sURL;
      string Id = dRView["Id"].ToString();
      return ResolveUrl("~/UserDetails.aspx?Id=" + Id);
  }
  public string getSRC(object imgSRC)
  {
      DataRowView dRView = (DataRowView)imgSRC;
      string ImageName = dRView["ImageName"].ToString();
      if (ImageName == "NoImage")
      {
          return ResolveUrl(@"~/UserImage/missing.jpg");
      }
      else
      {
          return ResolveUrl("~/UserImage/" + dRView["ImageName"].ToString());
      }
  }

为什么要使用DATAROWVIEW?数据列表已从DATATABLE获取数据


什么是DATAROWVIEW?


2)字符串SenderFriendId =(((HtmlInputHidden)e.Item.FindControl("hiddenId")).Value;此行的作用是什么?不需要这个.你只是喜欢这样

 <   a     href   ='  "   Id") ％> ' > 
                                  <   img     =' <％#getSRC(Container.DataItem," )   ="  中间"  border   ="    宽度  ="  > 
                              <  /a  >  
 



函数后面的ur代码看起来像这样



public string getHREF(object id)
    {
        
        return ResolveUrl("~/UserDetails.aspx?Id=" + Id.toString());
    }
    public string getSRC(object img)
    {
        
        if (ImageName == "NoImage")
        {
            return ResolveUrl(@"~/UserImage/missing.jpg");
        }
        else
        {
            return ResolveUrl("~/UserImage/" + img.ToString());
        }
    }
 
 
 
 1.)DATAROWVIEW:表示DataRow的自定义视图.

  http://msdn.microsoft.com/en-us/library/k65s5xs3 (v = VS.100).aspx  [ http://msdn.microsoft.com/en-us/library/system.data.datarowview.aspx  [










if (!Page.IsPostBack)
      {
          GetSearchResult(Request.QueryString["searchText"].ToString());
      }
  }
  public void GetSearchResult(string searchText)
  {
      string GetSearchResult = "Select * FROM [User] where Name like ''" + searchText+ "%''";
      dt = dbClass.ConnectDataBaseReturnDT(GetSearchResult);
      //if (dt.Rows.Count > 0)
      //{
          SearchResultList.DataSource = dt;
          SearchResultList.DataBind();
      //}
  }
  public string getHREF(object sURL)
  {
      DataRowView dRView = (DataRowView)sURL;
      string Id = dRView["Id"].ToString();
      return ResolveUrl("~/UserDetails.aspx?Id=" + Id);
  }
  public string getSRC(object imgSRC)
  {
      DataRowView dRView = (DataRowView)imgSRC;
      string ImageName = dRView["ImageName"].ToString();
      if (ImageName == "NoImage")
      {
          return ResolveUrl(@"~/UserImage/missing.jpg");
      }
      else
      {
          return ResolveUrl("~/UserImage/" + dRView["ImageName"].ToString());
      }
  }


WHY USE DATAROWVIEW? DATALIST ALREADY GET DATA FROM DATATABLE





WHAT IS DATAROWVIEW?





2) string SenderFriendId = ((HtmlInputHidden)e.Item.FindControl("hiddenId")).Value;WHAT THIS LINE DO?
解决方案
In Fact, you don''t need this. You just do like this



<a href='<%#getHREF(Container.DataItem,"Id")%>'>
                                  <img src='<%#getSRC(Container.DataItem,"ImageName") %>' align="middle" border="0" width="80px">
                              </a>




And ur code behind function will look like this



public string getHREF(object id)
    {
        
        return ResolveUrl("~/UserDetails.aspx?Id=" + Id.toString());
    }
    public string getSRC(object img)
    {
        
        if (ImageName == "NoImage")
        {
            return ResolveUrl(@"~/UserImage/missing.jpg");
        }
        else
        {
            return ResolveUrl("~/UserImage/" + img.ToString());
        }
    }

1.) DATAROWVIEW: Represents a customized view of a DataRow.

 http://msdn.microsoft.com/en-us/library/k65s5xs3(v=VS.100).aspx[^]



2.) This line is  retrieving the value from an HTML element which  allows you to store information in a nonviewable control on the form.http://msdn.microsoft.com/en-us/library/system.data.datarowview.aspx[^]



Both of these are links to MSDN you should learn how to search for the answers by using Google or MSDN. (Google usually provides the MSDN links). Copying code and not understanding what it does is a dangerous practice, most of the people here are happy to help but the answers you seek are easily found if you put in a small amount of time.



You probably found this site through a search engine, try instead entering the methods in question, you can easily find what they do and how to use them. This is meant as friendly advice, not meant to insult or denigrate your question.


                        
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