如何允许在GridView中排序 [英] How to allow sorting in GridView
本文介绍了如何允许在GridView中排序的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有以下GirdView，它显示了一些具有修改日期的文件:
I have the following GirdView which displays some files with its modified date:
<asp:GridView ID="GridView1" AllowSorting="true" OnSorting="GridView1_Sorting" ClientIDMode="Static" runat="server" AutoGenerateColumns="false" EmptyDataText="No PDF was generated">
<Columns>
<asp:BoundField DataField="Text" HeaderText="File Name" SortExpression="FileName" />
<asp:BoundField DataField="Value" HeaderText="File Date" SortExpression="FileDate" />
<asp:TemplateField>
<ItemTemplate>
<asp:LinkButton ID="lnkDownload" Text="Download" runat="server"
CommandArgument='<%# Container.DataItemIndex %>'
OnClick="DownloadFile" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:LinkButton ID="lnkView" Text="View in Browser"
CommandArgument='<%# Container.DataItemIndex %>'
OnClientClick="window.document.forms[0].target='blank';"
runat="server" OnClick="ViewFile" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
我正在用以下代码填充GridView:
I am populating the GridView with the following code:
if (!Page.IsPostBack)
{
BindData();
//MessageBox.Show(files.Count() + ""); // displays the count for the files being displayed
}
protected void BindData()
{
try
{
filePaths = Directory.GetFiles(@"C:\PDFGenerate");
files = new List<ListItem>();
foreach (string filePath in filePaths)
{
files.Add(new ListItem(Path.GetFileName(filePath), File.GetLastWriteTime(filePath).ToString()));
}
GridView1.DataSource = files;
GridView1.DataBind();
Session["fileData"] = files;
}
catch (Exception ce)
{
}
//MessageBox.Show(files.Count() + ""); // displays the count for the files being displayed
}
我在GridView中允许使用排序方法，并且还添加了排序表达式.我正在尝试编写允许排序的C#代码，但是由于我不使用SQL数据源，因此我不确定如何处理它:
I allowed the sorting method in the GridView and also added the sort expression. I am trying to write the C# code which will allow sorting but I'm not sure how I would go about it as I am not using a SQL data source:
protected void GridView1_Sorting(object server, GridViewSortEventArgs e)
{
switch (e.SortExpression)
{
case "FileName":
if (e.SortDirection == SortDirection.Ascending)
{
GridView1.DataSource = Session["fileData"];//DO BY ASCENDING
GridView1.DataBind();
}
else
{
GridView1.DataSource = Session["fileData"];//DO BY DESCENDING
GridView1.DataBind();
}
break;
case "FileDate":
break;
}
}
更新:如何使它正常工作...
UPDATE: How I was able to get it to work correctly...
protected void Page_Load(object sender, EventArgs e)
{
string strDirectory = @"C:\PDFGenerate\";
try
{
if (!Directory.Exists(strDirectory))
{
Directory.CreateDirectory(strDirectory);
}
}
catch (Exception ce)
{
//tc.Text = "Unable to create directory to save generated PDF files";
}
if (!Page.IsPostBack) //loaded first time...
{
//MessageBox.Show("Fires from a PAGE REFRESH or FIRST VISIT");
BindData();
}
else //loaded after an event (button click, link click, etc.)
{
//MessageBox.Show("Fires from an EVENT");
}
}
protected void BindData()
{
try
{
filePaths = Directory.GetFiles(@"C:\PDFGenerate");
files = new List<ListItem>();
foreach (string filePath in filePaths)
{
files.Add(new ListItem(Path.GetFileName(filePath), File.GetLastWriteTime(filePath).ToString()));
}
GridView1.DataSource = files;
GridView1.DataBind();
Session["fileData"] = files;
}
catch (Exception ce)
{
}
//MessageBox.Show(files.Count() + ""); // displays the count for the files being displayed
}
protected void GridView1_Sorting(object server, GridViewSortEventArgs e)
{
DataBind();
string strSortExpression = e.SortExpression;
switch (strSortExpression)
{
case "FileName":
if (e.SortExpression == (string)ViewState["SortColumn"])
{
// We are resorting the same column, so flip the sort direction
e.SortDirection =
((SortDirection)ViewState["SortColumnDirection"] == SortDirection.Ascending) ?
SortDirection.Descending : SortDirection.Ascending;
}
if (e.SortDirection == SortDirection.Ascending)
{
//MessageBox.Show("ASC");
var dataTable = ToDataTable((IList<ListItem>)Session["fileData"]);
var dataView = new DataView(dataTable);
dataView.Sort = string.Format("{0} {1}", "Text", e.SortDirection == SortDirection.Ascending ? "ASC" : "DESC");
GridView1.DataSource = dataView;
GridView1.DataBind();
}
else
{
//MessageBox.Show("DESC");
var dataTable = ToDataTable((IList<ListItem>)Session["fileData"]);
var dataView = new DataView(dataTable);
dataView.Sort = string.Format("{0} {1}", "Text", e.SortDirection == SortDirection.Descending ? "DESC" : "ASC");
GridView1.DataSource = dataView;
GridView1.DataBind();
}
ViewState["SortColumn"] = e.SortExpression;
ViewState["SortColumnDirection"] = e.SortDirection;
break;
case "FileDate":
if (e.SortExpression == (string)ViewState["SortColumn"])
{
// We are resorting the same column, so flip the sort direction
e.SortDirection =
((SortDirection)ViewState["SortColumnDirection"] == SortDirection.Ascending) ?
SortDirection.Descending : SortDirection.Ascending;
}
if (e.SortDirection == SortDirection.Ascending)
{
var dataTable = ToDataTable((IList<ListItem>)Session["fileData"]);
var dataView = new DataView(dataTable);
dataView.Sort = string.Format("{0} {1}", "Value", e.SortDirection == SortDirection.Ascending ? "ASC" : "DESC");
GridView1.DataSource = dataView;
GridView1.DataBind();
}
else
{
var dataTable = ToDataTable((IList<ListItem>)Session["fileData"]);
var dataView = new DataView(dataTable);
dataView.Sort = string.Format("{0} {1}", "Value", e.SortDirection == SortDirection.Descending ? "DESC" : "ASC");
GridView1.DataSource = dataView;
GridView1.DataBind();
}
ViewState["SortColumn"] = e.SortExpression;
ViewState["SortColumnDirection"] = e.SortDirection;
break;
}
}
public DataTable ToDataTable(IList<ListItem> data)
{
var table = new DataTable();
table.Columns.Add("Value", typeof(string));
table.Columns.Add("Text", typeof(string));
foreach (var item in data)
{
var row = table.NewRow();
row["Value"] = item.Value;
row["Text"] = item.Text;
table.Rows.Add(row);
}
return table;
}
推荐答案
尽管不建议将逻辑放在视图的代码后方，但您可以使用以下代码来实现:
Though it is not advised to place logic in your views' code-behind, you would achieve this with the following code:
protected void GridView1_Sorting(object server, GridViewSortEventArgs e)
{
switch (e.SortExpression)
{
case "FileName":
var dataTable = ToDataTable((IList<ListItem>)Session["fileData"]);
var dataView = new DataView(dataTable);
dataView.Sort = string.Format("{0} {1}",
e.SortExpression,
e.SortDirection == SortDirection.Ascending
? "ASC" : "DESC");
GridView1.DataSource = dataView;
GridView1.DataBind();
case "FileDate":
break;
}
}
此外，请确保您集合中的各项实现了 System.IComparable< T>
Also, make sure that the items in your collection implement System.IComparable<T>
最后，添加以下代码以将会话数据加载到dataTable中:
Finally, add the following code to load your session data into the dataTable:
public DataTable ToDataTable(IList<ListItem> data)
{
var table = new DataTable();
table.Columns.Add("Value", typeof(string));
table.Columns.Add("Text", typeof(string));
foreach (var item in data)
{
var row = table.NewRow();
row["Value"] = item.Value;
row["Text"] = item.Text;
table.Rows.Add(row);
}
return table;
}
这篇关于如何允许在GridView中排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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