ListView控件(一)--增，删，改，查

ASP.NET3.5中包含了新的数据绑定控件--ListView，这是一个类似与repeater与gridview结合的控件，可以实现添加，删除功能，同时还可以像repeater一样灵活的控制页面的布局。该控件包含了很多新的模板，比如GroupTemplate等新增的模板，可以方便的分组显示数据。详细的大家可以去查MSDN文档。

我一直认为学习数据绑定控件从最简单的增删改查开始，可以对该控件有较深刻的理解，这样可以举一反三，在进行综合运用。今天这篇文章还是从最基本的数据操作开始，对ListView有个感性的认识。

首先看一下程序运行的效果：

 

页面源码：

<asp:ListView ID="ListView1" runat="server" OnSelectedIndexChanging="ListView1_SelectedIndexChanging"

    OnItemCommand="ListView1_ItemCommand" OnItemEditing="ListView1_ItemEditing" OnItemCanceling="ListView1_ItemCanceling"

    OnItemDataBound="ListView1_ItemDataBound" OnPagePropertiesChanging="ListView1_PagePropertiesChanging"

    OnItemInserting="ListView1_ItemInserting" OnItemUpdating="ListView1_ItemUpdating"

    OnSorting="ListView1_Sorting" EnableViewState="true" InsertItemPosition="LastItem"

    OnItemDeleting="ListView1_ItemDeleting">

    <LayoutTemplate>

        <asp:PlaceHolder ID="itemPlaceholder" runat="server"></asp:PlaceHolder>

        <p>

            <asp:DataPager ID="MyPage" runat="server" PageSize="6">

                <Fields>

                    <asp:NumericPagerField ButtonCount="10" PreviousPageText="<-- " NextPageText="-->" />

                    <%...-- <asp:NextPreviousPagerField ButtonType="Button" ShowFirstPageButton="true" ShowLastPageButton="true"

ShowNextPageButton="true" ShowPreviousPageButton="true" /> --%>

                </Fields>

            </asp:DataPager>

        </p>

    </LayoutTemplate>

    <ItemTemplate>

        <i>

            <%...#Eval("SupplierID")%></i>

        <p>

            <b>

                <%...#Eval("CompanyName")%></b></p>

        <p>

            <%...#Eval("ContactName")%></p>

        <p>

            <%...#Eval("Address")%></p>

        <p>

            <%...#Eval("City")%></p>

        <asp:Button ID="btnEdit" runat="server" Text="Edit" CommandName="Edit" />

        <asp:Button ID="btnDelete" runat="server" Text="Delete" CommandName="Delete" />

        <%...--  <asp:LinkButton ID="lbtnSort" runat="server" Text="Sort" CommandName="Sort" CommandArgument="CompanyName" ></asp:LinkButton>--%>

    </ItemTemplate>

    <EditItemTemplate>

        <asp:TextBox ID="txtMy" runat="server" Text='<%#bind("SupplierID") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox1" runat="server" Text='<%#bind("CompanyName") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox2" runat="server" Text='<%#bind("ContactName") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox3" runat="server" Text='<%#bind("Address") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox4" runat="server" Text='<%#bind("City") %>'></asp:TextBox>

        <asp:Button ID="btnUpdate" runat="server" Text="Update" CommandName="Update" />

        <asp:Button ID="btnCancle" runat="server" Text="Cancle" CommandName="Cancel" />

    </EditItemTemplate>

    <InsertItemTemplate>

        <asp:TextBox ID="txtMy" runat="server" Text='<%#bind("SupplierID") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox1" runat="server" Text='<%#bind("CompanyName") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox2" runat="server" Text='<%#bind("ContactName") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox3" runat="server" Text='<%#bind("Address") %>'></asp:TextBox>

        <asp:TextBox ID="TextBox4" runat="server" Text='<%#bind("City") %>'></asp:TextBox>

        <asp:Button ID="btnUpdate" runat="server" Text="Insert" CommandName="Insert" />

        <asp:Button ID="btnCancle" runat="server" Text="Cancle" CommandName="Cancel" />

    </InsertItemTemplate>

    <ItemSeparatorTemplate>

        <div style="height: 0px; border-top: dashed 1px #ff0000">

        </div>

    </ItemSeparatorTemplate>

</asp:ListView>

这部分代码中有个重要的部分就是通过<LayoutTemplate>模板来设置控件的样式，布局，这也是新增的模板。在VS.NET2008的正式版本中，要正常运行页面必须在该模板中加入一个名为itemPlaceholder的PlaceHolder控件。要不会出现如下异常：

An item placeholder must be specified on ListView 'ListView1'. Specify an item placeholder by setting a control's ID property to "itemPlaceholder".

<ItemTemplate>模板用来绑定显示到页面上的数据， <EditItemTemplate>用来显示处于编辑状态的时候显示的数据，其他的可以以此类推。

与ListView还搭配的一起使用了新增的DataPager控件，这个主要是用于ListView控件的分页，是新增的分页空也，可以方便，高效的进行分页。

后台代码：

string ConStr = ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString; protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { ViewState["SupplierID"] = "SupplierID"; ViewState["Direction"] = "DESC"; BindListView(); } } private void BindListView() { string QueryCon = "SELECT SupplierID,CompanyName,ContactName,Address,City FROM Suppliers"; SqlConnection NorthWindCon = new SqlConnection(ConStr); SqlDataAdapter NorthWindDa = new SqlDataAdapter(QueryCon, ConStr); DataSet Ds = new DataSet(); NorthWindDa.Fill(Ds, "Suppliers"); ListView1.DataKeyNames = new string[] { "SupplierID" }; DataView Dv = Ds.Tables["Suppliers"].DefaultView; //排序表达式 string SortExpress = (string)ViewState["SupplierID"] + " " + (string)ViewState["Direction"]; Dv.Sort = SortExpress; //绑定数据源 //ListView1.DataSource = Ds.Tables["Suppliers"]; ListView1.DataSource = Dv; ListView1.DataBind(); } protected void ListView1_ItemEditing(object sender, ListViewEditEventArgs e) { ListView1.EditIndex = e.NewEditIndex; BindListView(); } protected void ListView1_ItemDataBound(object sender, ListViewItemEventArgs e) { if (e.Item.ItemType == ListViewItemType.DataItem) { ((Button)e.Item.FindControl("btnDelete")).Attributes["onclick"] = "if(!confirm('你真的要删除这条记录么?'))return false;"; } } protected void ListView1_ItemCanceling(object sender, ListViewCancelEventArgs e) { //取消编辑 if (e.CancelMode == ListViewCancelMode.CancelingEdit) { //e.Cancel = true; ListView1.EditIndex = -1; BindListView(); ShowMessage("取消编辑"); } else if (e.CancelMode == ListViewCancelMode.CancelingInsert) { //BindListView(); return; } } protected void ListView1_ItemInserting(object sender, ListViewInsertEventArgs e) { ((TextBox)ListView1.InsertItem.FindControl("txtMy")).ReadOnly = true; string CompanyName = Server.HtmlEncode(((TextBox)ListView1.InsertItem.FindControl("TextBox1")).Text.ToString()); string ContactName = Server.HtmlEncode(((TextBox)ListView1.InsertItem.FindControl("TextBox2")).Text.ToString()); string Address = Server.HtmlEncode(((TextBox)ListView1.InsertItem.FindControl("TextBox3")).Text.ToString()); string City = Server.HtmlEncode(((TextBox)ListView1.InsertItem.FindControl("TextBox4")).Text.ToString()); string InsertQuery = "INSERT INTO Suppliers (CompanyName,ContactName,Address,City) VALUES ('" + CompanyName + "','" + ContactName + "','" + Address + "','" + City + "')"; SqlConnection InsertCon = new SqlConnection(ConStr); SqlCommand InsertCmd = new SqlCommand(InsertQuery, InsertCon); try { InsertCon.Open(); InsertCmd.ExecuteNonQuery(); BindListView(); //将插入行显示到最后 ListView1.InsertItemPosition = InsertItemPosition.LastItem; } catch { ShowMessage("插入新数据出错，请重新输入"); } finally { InsertCon.Dispose(); InsertCmd.Dispose(); } } protected void ListView1_ItemUpdating(object sender, ListViewUpdateEventArgs e) { string KeyId = ListView1.DataKeys[e.ItemIndex].Value.ToString(); //找到listview改行的数据集合 string CompanyName = Server.HtmlEncode(((TextBox)ListView1.Items[e.ItemIndex].FindControl("TextBox1")).Text.ToString()); string ContactName = Server.HtmlEncode(((TextBox)ListView1.Items[e.ItemIndex].FindControl("TextBox2")).Text.ToString()); string Address = Server.HtmlEncode(((TextBox)ListView1.Items[e.ItemIndex].FindControl("TextBox3")).Text.ToString()); string City = Server.HtmlEncode(((TextBox)ListView1.Items[e.ItemIndex].FindControl("TextBox4")).Text.ToString()); string UpdateStr = "UPDATE Suppliers SET CompanyName='" + CompanyName + "',ContactName='" + ContactName + "'," + "Address='" + Address + "',City='" + City + " 'WHERE SupplierID='" + KeyId + "' "; SqlConnection UpdateCon = new SqlConnection(ConStr); SqlCommand UpdateCmd = new SqlCommand(UpdateStr, UpdateCon); try { UpdateCon.Open(); UpdateCmd.ExecuteNonQuery(); ListView1.EditIndex = -1; BindListView(); } catch { ShowMessage("更新出错，请重新编辑"); } finally { UpdateCon.Dispose(); UpdateCmd.Dispose(); } } protected void ListView1_Sorting(object sender, ListViewSortEventArgs e) { if (ViewState["SupplierID"].ToString() == e.SortExpression) { if (ViewState["Direction"].ToString() == "DESC") { ViewState["Direction"] = "ASC"; } else { ViewState["Direction"] = "DESC"; } } else { ViewState["SupplierID"] = e.SortExpression; } BindListView(); } private void ShowMessage(string Message) { Literal TxtMsg = new Literal(); TxtMsg.Text = "<mce:script type="text/javascript"><!-- alert('" + Message + "') // --></mce:script>"; Page.Controls.Add(TxtMsg); } protected void ListView1_ItemDeleting(object sender, ListViewDeleteEventArgs e) { string KeyID = ListView1.DataKeys[e.ItemIndex].Value.ToString(); string DeleteStr = "DELETE FROM Suppliers WHERE SupplierID='" + KeyID + "'"; SqlConnection DeleteCon = new SqlConnection(ConStr); SqlCommand DeleteCmd = new SqlCommand(DeleteStr, DeleteCon); try { DeleteCon.Open(); DeleteCmd.ExecuteNonQuery(); BindListView(); ShowMessage("删除成功"); } catch { ShowMessage("删除出错，请检查数据是否有关联"); } finally { DeleteCon.Dispose(); DeleteCmd.Dispose(); } }

以前的edit_cancel事件在ListView控件中为item_cancel，在该事件中可以判断是取消编辑还是取消插入新的数据。大家可以看代码。本篇文章主要是对ListView控件一些基本的事件的运用。下一篇会继续深入的学习该控件。

 

 来自：http://blog.youkuaiyun.com/oyjd614/archive/2007/12/05/1919195.aspx