Gridview RowCommand 事件后不显示 Gridview？

Question

我有一个显示餐厅列表的 GridView，它是我数据库中的数据。在最后一栏中，我有一个ButtonField。当用户单击该按钮时，RowCommand 会触发，另一个 GridView 会显示所选餐厅的评论。

我遇到的问题是，当 RowCommand 事件被触发时，第二个 GridView gvReviews 根本没有出现。

• 我尝试将 GridView 的 visible 设置为 true，但没有 似乎工作。
• 我曾尝试将TemplateField 与Button 一起使用，但这也不起作用。
• 我尝试过使用if (!IsPostback) 语句

这是我的 GridViews 的 sn-p：

<asp:GridView ID="gvRestaurants" runat="server" AutoGenerateColumns="false" OnRowCommand="gvRestaurants_RowCommand">
            <Columns>
                <asp:BoundField DataField="RestaurantID" HeaderText="ID" />
                <asp:BoundField DataField="RestName" HeaderText="Restaurant" />
                <asp:BoundField DataField="RestAddr" HeaderText="Address" />
                <asp:BoundField DataField="RestCity" HeaderText="City" />
                <asp:BoundField DataField="RestState" HeaderText="State" />
                <asp:BoundField DataField="RestZip" HeaderText="Zip Code" />
                <asp:BoundField DataField="CategoryDesc" HeaderText="Category" />
                <asp:ButtonField HeaderText="Reviews" CommandName="viewReviews" Text="View" ButtonType="Button" />
            </Columns>
        </asp:GridView>
        <asp:GridView ID="gvReviews" runat="server" AutoGenerateColumns="false">
            <Columns>
                <asp:BoundField DataField="RestaurantID" HeaderText="ID" />
                <asp:BoundField DataField="RestName" HeaderText="Restaurant" />
                <asp:BoundField DataField="ReviewDate" HeaderText="Date of Review" />
                <asp:BoundField DataField="FoodQuality" HeaderText="Food Quality" />
                <asp:BoundField DataField="ServiceRating" HeaderText="Service" />
                <asp:BoundField DataField="AtmosphereRating" HeaderText="Atmosphere" />
                <asp:BoundField DataField="PriceRating" HeaderText="Price" />
                <asp:BoundField DataField="ReviewText" HeaderText="Review" />
            </Columns>
        </asp:GridView>

这是 aspx.cs 的 sn-p

protected void btnSearch_Click(object sender, EventArgs e)
        {
            gvRestaurants.Visible = true;
            gvAllRestaurants.Visible = false;
            DataSet ds = p.SearchByCategory(ddCategories.SelectedItem.Value, ddCategories2.SelectedItem.Value);
            gvRestaurants.DataSource = ds;
            gvRestaurants.DataBind();
        }

 protected void gvRestaurants_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            if (e.CommandName == "viewReviews")
            {
                int index = Convert.ToInt32(e.CommandArgument);
                GridViewRow row = gvRestaurants.Rows[index];

                int restID = int.Parse(row.Cells[0].Text);

                gvReviews.DataSource = p.GetReview(restID);
                gvReviews.DataBind();

                gvRestaurants.Visible = false;
                gvReviews.Visible = true;
            }
            else
            {
                string error = "There are no reviews for this restaurant.";
                ClientScript.RegisterStartupScript(this.GetType(), "myalert", "alert('" + error + "');", true);
            }

这是我使用的方法的 sn-p：

public DataSet SearchByCategory(string category1, string category2)
        {
            DBConnect objDB = new DBConnect();
            objCmd.Parameters.Clear();
            objCmd.CommandType = CommandType.StoredProcedure;
            objCmd.CommandText = "GetRestaurantByCategory";

            SqlParameter sqlParameter = new SqlParameter("@theCategory", category1);
            SqlParameter sqlParameter2 = new SqlParameter("@theCategory2", category2);

            sqlParameter.Direction = ParameterDirection.Input;
            sqlParameter.SqlDbType = SqlDbType.VarChar;
            sqlParameter.Size = 50;

            sqlParameter2.Direction = ParameterDirection.Input;
            sqlParameter2.SqlDbType = SqlDbType.VarChar;
            sqlParameter2.Size = 50;

            objCmd.Parameters.Add(sqlParameter);
            objCmd.Parameters.Add(sqlParameter2);

            objDB.GetConnection().Open();
            DataSet ds = objDB.GetDataSetUsingCmdObj(objCmd);
            objDB.CloseConnection();

            return ds;
        }

        public DataSet GetReview(int restaurant)
        {
            DBConnect objDB = new DBConnect();
            objCmd.Parameters.Clear();
            objCmd.CommandType = CommandType.StoredProcedure;
            objCmd.CommandText = "GetReviewByRestaurantID";

            SqlParameter sqlParameter = new SqlParameter("@theRestaurantID", restaurant);

            sqlParameter.Direction = ParameterDirection.Input;
            sqlParameter.SqlDbType = SqlDbType.Int;
            sqlParameter.Size = 4;

            objCmd.Parameters.Add(sqlParameter);

            objDB.GetConnection().Open();
            DataSet ds = objDB.GetDataSetUsingCmdObj(objCmd);
            objDB.CloseConnection();

            return ds;
        }

这是我使用的存储过程：

CREATE PROCEDURE [dbo].GetRestaurantByCategory
    @theCategory varchar(50),
    @theCategory2 varchar(50)

AS
    SELECT rest.RestaurantID, rest.RestName, rest.RestAddr, rest.RestCity, rest.RestState, rest.RestZip, cat.CategoryDesc
    FROM Restaurants rest JOIN Categories cat ON rest.CategoryID = cat.CategoryID
    WHERE CategoryDesc = @theCategory OR CategoryDesc = @theCategory2

CREATE PROCEDURE [dbo].GetReviewByRestaurantID
    @theRestaurantID int

AS
    SELECT rest.RestaurantID, rest.RestName, rev.ReviewDate, rev.FoodQuality, rev.ServiceRating, rev.AtmosphereRating, rev.PriceRating, rev.ReviewText
    FROM Restaurants rest JOIN Reviews rev ON rest.RestaurantID = rev.RestaurantID
    WHERE Rest.RestaurantID = @theRestaurantID

Answer 1

您的GridView 未显示，因为您将其绑定到DataSet，而不是直接将其绑定到此DataSet 中的DataTable。

尝试更改此行：

gvReviews.DataSource = p.GetReview(restID);

到这里：

gvReviews.DataSource = p.GetReview(restID).Tables[0];

Answer 2

使用这个查询

SELECT rest.RestaurantID, rest.RestName, rev.ReviewDate, rev.FoodQuality, rev.ServiceRating, rev.AtmosphereRating, rev.PriceRating, rev.ReviewText
    FROM Restaurants rest JOIN Reviews rev ON rev.RestaurantID = rest.RestaurantID
    WHERE Rest.RestaurantID = @theRestaurantID