• GridView使用初步


    (1)RowCommand事件使用

    页面:

     <asp:TemplateField HeaderText="用户状态">
              <ItemTemplate>
                    <asp:LinkButton runat="server" ID="lnkbtnStatus" CommandArgument='<%# Eval("Id") %>' CommandName="UpStatus" Text='<%# Eval("UserState.Name") %>'></asp:LinkButton>
              </ItemTemplate>
    </asp:TemplateField>    

    代码:

        //模版列中的按钮也会触发RowCommand事件

        protected void gvMain_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            //预留其他命令
            switch (e.CommandName)
            {
                case "UpStatus":
                        UserManager.ModifyUserStatusById(Convert.ToInt32(e.CommandArgument));
                        BindGridView();
                    break;
                default:
                    break;
            }
        }        

    (2)全选

    页面:

    <asp:TemplateField HeaderText="全选">
             <ItemTemplate>
                   <asp:CheckBox runat="server" ID="chkSelect" />
             </ItemTemplate>
            <HeaderTemplate>
                  &nbsp;<input id="cbAll" type="checkbox" onclick="GetAllCheckBox(this)" />全选
            </HeaderTemplate>
    </asp:TemplateField>

    <asp:TemplateField Visible="False">
            <ItemTemplate>
                    <asp:Label ID="lblId" runat="server" Text='<%# Bind("Id") %>'></asp:Label>
             </ItemTemplate>
    </asp:TemplateField>

    <script language="javascript">
    function GetAllCheckBox(CheckAll)
    {
     var items = document.getElementsByTagName("input");    
     for(i=0; i<items.length;i++)
     {      
       if(items[i].type=="checkbox")
       {
            items[i].checked = CheckAll.checked;
       }
     }
    }
    </script>

    代码:

        protected void btnSure_Click(object sender, EventArgs e)
        {
            string sb =String.Empty;
            for (int i = 0; i < this.gvBooks.Rows.Count; i++)
            {
                CheckBox cb = (gvBooks.Rows[i].FindControl("chkSelect")) as CheckBox;
                if (cb.Checked == true)
                {
                    sb += (gvBooks.Rows[i].FindControl("lblId") as Label).Text+",";               
                }
            }
            string catagory = this.ddlCatagory.SelectedItem.Value;    
           if (sb.Length > 0)
            {
                sb = sb.Substring(0, sb.Length - 1);
            }
            DBHelper.ExecuteCommand("update Books set CategoryId=" + catagory + " where id in(" + sb + ")");

    }

    (3)RowDataBound事件使用

     3.1 鼠标所在行变色、对某些数据列值显示时进行截断处理

        protected void gvBooks_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                e.Row.Attributes.Add("onmouseover", "currentcolor=this.style.backgroundColor;this.style.backgroundColor='#6699ff'");
                e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor=currentcolor");

                if (e.Row.Cells[6].Text.Length > 4)
                {
                    e.Row.Cells[6].ToolTip = e.Row.Cells[6].Text;
                    e.Row.Cells[6].Text = e.Row.Cells[6].Text.Substring(0, 4) + "... ";

                }
            }
        }

    3.2 根据条件,设置相应行的前景色(背景色)

                if (e.Row.RowType==DataControlRowType.DataRow)   //判断是否是数据
                {

                    DateTime sxrq = Convert.ToDateTime(e.Row.Cells[10].Text);  //有效期字段
                    if ((sxrq - DateTime.Today).Days < 180)  //sxrq-当天日期<180天
                    {
                        e.Row.ForeColor = System.Drawing.Color.Red;  //设置前景色
                    }
                } 

    3.3 实现GridView控件中数据自动求和功能

    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)

    {

       if  (e.Row.RowIndex >= 0)

       {

          sum += Convert.ToInt32(e.Row.Cells[4].Text);

        }

        else if (e.Row.RowType == DataControlRowType.Footer)

        {

          e.Row.Cells[1].Text = "总分为:";

          e.Row.Cells[2].Text = sum.ToString();

          e.Row.Cells[3].Text = "平均分为:";

          e.Row.Cells[4].Text = ((int)(sum / GridView1.Rows.Count)).ToString();

        }

    }

    3.4 在RowDataBound事件中取值

    3.4.1 e.Row.Cells[x].Text

    不能取得隐藏列的值

    3.4.2 e.Row.Cells[x].FindControl("ControlName")。

    用于取得模版列的值

    3.4.3 (DataRowView)e.Row.DataItem).Row.ItemArray[x].ToString()。
      此法的核心是e.Row.DataItem,它是GridView的行数据集,为Object类型,将其转化为DataRowView类型后,可以获得更多的操作方法。此数据集表示数据源当前行的全部字段列,ItemArray[x]是当前行全部字段列的数组对象,可以通过索引x获得任意字段值,可以对数据源的全部字段查询。

    3.4.4 取主键的值

    GridView1.DataKeys[e.Row.RowIndex].Value

    3.5 GridView实现删除时弹出确认对话框

        protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            //如果是绑定数据行
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                 if (e.Row.RowState == DataControlRowState.Normal || e.Row.RowState == DataControlRowState.Alternate)
                {
                    ((LinkButton)e.Row.Cells[6].Controls[0]).Attributes.Add("onclick", "javascript:return confirm('你确认要删除:/"" + e.Row.Cells[1].Text + "/"吗?')");
                }
            }

        }

     

    (4)实现删除、自定义删除、编辑功能

    删除功能:       

             设置GridView控件的DataKeyNames属性为StudentID。通过GridView智能标记,编辑列,添加CommandField中的“删除”字段,设置HeadText属性。当用户单击“删除”按钮时,会触发RowDeleting和RowDeleted事件,我们通过编写RowDeleting事件处理代码,实现记录删除功能。关键代码如下:

                string sid = GridView1.DataKeys[e.RowIndex].Value.ToString();

                String sql = "delete from StudentScore where StudentID=@StudentID";

                OleDbCommand cmd = new OleDbCommand(sql, conn);

                cmd.Parameters.AddWithValue("@StudentID", sid);//演示sql参数使用

    自定义删除: 

         通过GridView智能标记,编辑列,添加ButtonField的字段,设置HeadText属性为“自定义删除”,DataTextField属性为StudentID,DataTextFormatString属性为删除"{0}"的记录,CommandName属性为del。当用户单击ButtonField时,会触发GridView控件的RowCommand事件,其参数e有以下重要属性:

            e.CommandName属性表明哪个按钮被单击

            e.CommandArgument属性表明是哪一行

        可以通过编写RowCommand事件处理代码,实现记录删除。关键代码如下:

     if (e.CommandName == "del")          //判断是哪个按钮

     {

         int rowindex = Convert.ToInt32(e.CommandArgument);  //获取行索引

         string sid = GridView1.DataKeys[rowindex].Value.ToString();

            ----

     }

    编辑:

           通过GridView智能标记,编辑列,添加ButtonField的字段,设置HeadText属性为“编辑”,CommandName属性为myedit。当用户单击ButtonField时,同样会触发GridView控件的RowCommand事件,在此事件中编写代码,将当前记录信息在文本框中显示出来,以供用户修改:

            if (e.CommandName == "myedit")

            {

                ViewState["m"] = 1;                           //标志位,表示修改记录

                int rowindex = Convert.ToInt32(e.CommandArgument);  //获取行索引

                GridViewRow row = GridView1.Rows[rowindex];

                lblCaption.Text = "编辑学生成绩";

                txtStudentID.Enabled = false;   //学号不允许更改

                txtStudentID.Text = row.Cells[0].Text;

                txtName.Text = row.Cells[1].Text;

                txtMath.Text = row.Cells[2].Text;

                txtChinese.Text = row.Cells[3].Text;

                txtEnglish.Text = row.Cells[4].Text;

            }

    知识点扩展:

    当用户单击ButtonField时,会触发GridView控件的RowCommand事件,其参数e.CommandName属性特别值得注意。当一个ButtonField的CommandName是以下预定义值是,会触发特定的事件:

    CommandName 值

    说明

    “Cancel”

    取消编辑操作并将 GridView 控件返回为只读模式。引发 RowCancelingEdit 事件。

    “Delete”

    删除当前记录。引发 RowDeletingRowDeleted 事件。

    “Edit”

    将当前记录置于编辑模式。引发 RowEditing 事件。

    “Page”

    执行分页操作。将按钮的 CommandArgument 属性设置为“First”、“Last”、“Next”、“Prev”或页码,以指定要执行的分页操作类型。引发 PageIndexChangingPageIndexChanged 事件。

    “Select”

    选择当前记录。引发 SelectedIndexChangingSelectedIndexChanged 事件。

    “Sort”

    GridView 控件进行排序。引发 SortingSorted 事件。

    “Update”

    更新数据源中的当前记录。引发 RowUpdatingRowUpdated 事件。

    模板列中的按钮的CommandName如果是上述预定义值时,也会触发特定的事件。如下面的按钮同样会触发RowDeleting事件:

    <asp:TemplateField HeaderText="删除" ShowHeader="False">
    <ItemTemplate>
    <asp:LinkButton ID="LinkButton1" runat="server" CausesValidation="False" CommandName="Delete" OnClientClick="return confirm('确定删除吗?')" Text="删除"></asp:LinkButton>
    </ItemTemplate>
    </asp:TemplateField>

    (5)排序

           首先,设置GridView的AllowSorting="True",将导致用户单击GridView自动生成列的标题时,触发Sorting事件;或者,直接调用Sort()方法,也会触发Sorting事件,如:

            //在此处会激发GridView的Sorting事件,第一个参数将被传送到Sorting事件的参数e中
            GridView1.Sort("ClientName", SortDirection.Ascending);

            在Sorting事件中以数据源进行排序,然后重新绑定数据并显示,如:

           //获取要显示的记录集
            List<ClientInfo> clients = GetAllClients();
            //判断是哪个控件引发的排序
            switch (e.SortExpression)
            {
                case "ClientName":
                    clients.Sort(CompareByClientName); //数据源排序
                    break;
                ------
            }
            //重新绑定数据并显示
            GridView1.DataSource = clients;
            GridView1.DataBind();

       使用DataView进行排序的方法如下:

            protected void Page_Load(object sender, EventArgs e)
            {
                if (!IsPostBack)
                {
                    ViewState["SortOrder"] = "ASC";//排序顺序
                    ViewState["SortField"] = "GradeId";//排序字段
                    Bind();
                }
            }

            public void Bind()
            {
                DataView view = bll.GetAllGrade().DefaultView;
                view.Sort = ViewState["SortField"] + " " + ViewState["SortOrder"];
                GridView1.DataSource = view;
                GridView1.DataBind();
            }

            protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
            {
                if (e.SortExpression.ToString() == ViewState["SortField"].ToString())
                {
                    if(ViewState["SortOrder"].ToString() == "Asc")
                    {
                        ViewState["SortOrder"] ="Desc";
                    }
                    else
                       ViewState["SortOrder"] ="Asc";
                }
                else
                {
                    ViewState["SortField"] = e.SortExpression;
                }
                Bind();
            }

    (6)GridView显示行的序号:
    <asp:GridView ID="GridView1" runat="server">
        <Columns>       
            <asp:TemplateField>           
                <ItemTemplate>               
                    <%#Container.DataItemIndex+1 %>               
                </ItemTemplate>       
            </asp:TemplateField>   
        </Columns>
    </asp:GridView>

    (7)GridView各个事件中获取主键值

    在 GridView1_RowDataBound中获取主键的值
    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
         int index = GridView1.DataKeys[e.Row.RowIndex].Value;
    }

    如果DataKeyNames属性是多个字段,如DataKeyNames="SubjectID,Mode",则获取键值的代码如下

    VoteView.DataKeys[e.Row.RowIndex].Values["Mode"].ToString()

    //删除事件
    在 GridView1_RowDeleting中获取主键的值
    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
         int index=GridView1.DataKeys[e.RowIndex].Value;
    }

    如果是复合主键,在前台页面指定复合主键DataKeyNames="sno,cno",然后用下面的代码获取复合主键

    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        //string sno = GridView1.Rows[e.RowIndex].Cells[0].Text;
        //string cno = GridView1.Rows[e.RowIndex].Cells[2].Text;
        string sno = GridView1.DataKeys[e.RowIndex].Values[0].ToString();
        string cno = GridView1.DataKeys[e.RowIndex].Values[1].ToString();
        Response.Write(sno + "," + cno);

    //分页事件
    在 GridView1_PageIndexChanging中获取主键的值
    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
         int index=GridView1.DataKeys[e.NewPageIndex].Value;
    }

    在 GridView1_RowCommand中获取主键的值:
    protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
         int index = GridView1.DataKeys[Convert.ToInt32(e.CommandArgument)].Value;
    }

    在 GridView1_RowEditing中获取主键的值
    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {
         int index = GridView1.DataKeys[e.NewEditIndex].Value;
    }

    在 GridView1_RowUpdating中获取主键的值
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
          int index = GridView1.DataKeys[e.RowIndex].Value;
    }

    (8)分页(GridView自带的分页功能)

    设置属性:

       AllowPaging="True"

       PageSize="2"

    处理PageIndexChanging事件:

            protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
            {  
                GridView1.PageIndex= e.NewPageIndex;
                Bind();
            }

    (9)模版列使用

    <asp:TemplateField HeaderText="用户操作">
        <ItemTemplate>
            <asp:ImageButton ID="ImageButton1" runat="server"
                CommandArgument='<%# Eval("id") %>' CommandName="myedit"
                ImageUrl="~/images/31.gif" />
            <asp:ImageButton ID="ImageButton2" runat="server"
                CommandArgument='<%# Eval("id") %>' CommandName="mydel"
                ImageUrl="~/images/061.GIF" />
            <a href='ContactEdit.aspx?id=<%#Eval("id")%>'>编辑</a>
            <a href='ContactEdit.aspx?id=<%#((System.Data.DataRowView)(Container.DataItem))["id"]%>'>编辑</a>
        </ItemTemplate>
    </asp:TemplateField> 

    Eval通过反射来完成,会损失性能,可以用<%#((System.Data.DataRowView)(Container.DataItem))["id"]%>来提升性能。

    protected void gvContact_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "myedit")
        {
            Response.Write(e.CommandArgument.ToString());
        }
        else
            if(e.CommandName=="mydel")
            {
                Response.Write(e.CommandArgument.ToString());
            }

  • 相关阅读:
    纹理贴图的模式设置
    vs debug或者release文件夹下的 .exe文件
    subpixel的概念
    点乘
    设置开机时自动开启和关闭的软件
    CF553E Kyoya and Train
    CF960G Bandit Blues
    玩游戏
    「SWTR03」Counting Trees
    CF623E Transforming Sequence
  • 原文地址:https://www.cnblogs.com/zhouhb/p/2035401.html
Copyright © 2020-2023  润新知