更新數據到GridView控件在asp.net

Question

我是比較新的asp.net.So請多多包涵，如果我的查詢是幼稚 我的網格設計：

<asp:GridView runat ="server" GridLines = "Both" DataKeyNames="book_id"AutoGenerateColumns ="false" CellPadding ="5" CellSpacing ="5" allowpaging="True" allowsorting="True" 
ID="gv_table1" EmptyDataText ="No data exists"  OnRowEditing="gv_RowEditing" 
OnRowCancelingEdit="gv_RowCancelingEdit" OnRowUpdating="gv_RowUpdating" OnRowDeleting="gv_RowDeleting"> 
    <Columns> 

<asp:BoundField HeaderText="Book ID" DataField="book_id"> 

</asp:BoundField> 



<asp:BoundField DataField="book_name" HeaderText="Book Name"> 

</asp:BoundField> 
<asp:BoundField DataField="author_name" HeaderText="Author Name"> 

</asp:BoundField> 
<asp:BoundField DataField="publisher" HeaderText="Publisher"> 

</asp:BoundField> 
<asp:BoundField DataField="year_edition" HeaderText="Year/Edition"> 

</asp:BoundField> 
<asp:BoundField DataField="total_no" HeaderText="Total No"> 

</asp:BoundField> 
<asp:BoundField DataField="available" HeaderText="Available"> 

</asp:BoundField> 
<asp:BoundField DataField="tags" HeaderText="Tags"> 

</asp:BoundField> 
<asp:BoundField DataField="fare" HeaderText="Fare"> 

</asp:BoundField> 
<asp:BoundField DataField="state" HeaderText="State"> 

</asp:BoundField> 
<asp:templatefield HeaderText ="Options"> 
           <itemtemplate > 

             <asp:linkbutton id="btnEdit" runat="server" commandname="Edit" text="Edit" /> 

             <asp:linkbutton id="btnDelete" runat="server" commandname="Delete" text="Delete" /> 
           </itemtemplate> 
           <edititemtemplate> 
             <asp:linkbutton id="btnUpdate" runat="server" commandname="Update" text="Update" /> 
             <asp:linkbutton id="btnCancel" runat="server" commandname="Cancel" text="Cancel" /> 
           </edititemtemplate> 
         </asp:templatefield> 





</Columns> 
</asp:GridView> 

我後面的代碼：

public void gv_RowUpdating(object sender, GridViewUpdateEventArgs e) 
    { 

     int bookid = Convert.ToInt32(gv_table1.DataKeys[e.RowIndex].Values["book_id"].ToString()); 
     string bookname =(gv_table1.Rows[e.NewValues].Cells[1].Controls[0] as TextBox).Text; 
     string bookname = (gv_table1.Rows[e.RowIndex].FindControl("author_name") as TextBox).Text; 

     string book = gv_table1.Rows[e.RowIndex].Cells[1].Text ; 
} 

我能夠刪除，但不能編輯data.I我不能夠得到改變的值，我在網格視圖。我進入盡力讓我那是在GridView控件編輯或更改前的值。 在此先感謝朋友。

Answer 1

我不認爲我們可以利用查找控制方法訪問綁定字段。 author_name是使用FindControl無法訪問它的綁定域中的數據字段的名稱，它不是控件。

使用e.RowIndex獲得更新的值。

public void gv_RowUpdating(object sender, GridViewUpdateEventArgs e) 
{ 
    string bookname = ((TextBox)(gv_table1.Rows[e.RowIndex].Cells[1].Controls[0])).Text; 

         // OR 
    string bookname =(gv_table1.Rows[e.RowIndex].Cells[1].Controls[0] as TextBox).Text; 
    gv_table1.EditIndex = -1; // reset the edit index 
    // Again Bind the gridview to show updated data 
} 

更新答：

問題： The problem is that you are binding your gridview on each post back

解決方案：

爲了測試它，我創建了一個GridView控件添加兩個欄，我得到了老如果我在每個回發上綁定gridview，則會使用這些值。爲了避免它，只需在綁定網格前添加Page.IsPostBack檢查。

protected void Page_Load(object sender, EventArgs e) 
{ 
    if (!Page.IsPostBack) // If you not place this check then you will get the old values because GridView in Bind on every postback 
    { 
     BindGrid(); // Bind you grid here 
    } 
} 

我的完整代碼：

// Aspx Code 
<asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server" 
    AllowPaging="True" 
    onrowediting="GridView1_RowEditing" onrowupdating="GridView1_RowUpdating" onrowcancelingedit="GridView1_RowCancelingEdit" 
    >   
    <Columns> 
     <asp:BoundField DataField="Name" HeaderText="Name" /> 
     <asp:BoundField DataField="City" HeaderText="Name" /> 
     <asp:CommandField ShowEditButton ="true" ShowCancelButton="true" ShowDeleteButton="true" /> 
    </Columns> 
</asp:GridView> 

// Aspx Code Behind 
protected void Page_Load(object sender, EventArgs e) 
{ 
    if (!Page.IsPostBack) // If you not place this check then you will get the old values because GridView in Bind on every postback 
    { 
     BindGrid(); 
    } 
} 
private void BindGrid() // function for binding gridview 
{ 
    DataTable dt = new DataTable(); 
    dt.Columns.Add("Name"); 
    dt.Columns.Add("City"); 

    DataRow r = dt.NewRow(); 
    r[0] = "Name 1"; 
    r[1] = "City 1"; 

    DataRow r1 = dt.NewRow(); 
    r1[0] = "Name 2"; 
    r1[1] = "City 2"; 

    dt.Rows.Add(r); 
    dt.Rows.Add(r1); 

    GridView1.DataSource = dt; 
    GridView1.DataBind(); 
} 


protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e) 
{ 
    GridView1.EditIndex = e.NewEditIndex; // setting new index 
    BindGrid(); 
} 


protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e) 
{ 
    GridViewRow row = GridView1.Rows[e.RowIndex]; 
    string newvalue = ((TextBox)row.Cells[0].Controls[0]).Text; 
    GridView1.EditIndex = -1; // Again reset 
} 

protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) 
{ 
    GridView1.EditIndex = -1; // reseting grid view 
    BindGrid(); 
} 

Answer 2

我寫了所有的代碼，你儘管你可能不需要一些。希望你可以從中學習並適用於你的。但是這個代碼確實有效。但首先，如果我是你，我會爲書籍ID創建一個項目模板並將其作爲標籤。那就是你的控制。您還需要使用參數來防止sql注入。有很多方法可以做到這一點，但這只是我如何做到的。希望這會有所幫助。

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e) 
{ 
    //Identify your control i.e. the primary key (lblbookid is the name of the item template) 
    GridViewRow row = GridView1.Rows[e.RowIndex]; 
    Label bookidLabel = (Label)row.FindControl("lblbookid"); 

    //connect to db which you probably already have 
    string strSQLConnection = ("server=blah;database=blah;uid=blah;pwd=blah"); 
    SqlConnection sqlConnection = new SqlConnection(strSQLConnection); 

    SqlCommand cmd = new SqlCommand(); 

    cmd.CommandText = "UPDATE yourtable SET book_name = @book_name WHERE book_id = @book_id"; 

    //parameters 
    cmd.Parameters.Add("@bookid", SqlDbType.Char).Value = bookidLabel.Text; 
    cmd.Parameters.Add("@book_name", SqlDbType.Char).Value = ((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]).Text; 
    cmd.Parameters.Add("@book_author", SqlDbType.Char).Value = ((TextBox)GridView1.Rows[e.RowIndex].Cells[3].Controls[0]).Text; 

    cmd.Connection = sqlConnection; 
    sqlConnection.Open(); 
    cmd.ExecuteNonQuery(); 



    sqlConnection.Close(); 

    GridView1.EditIndex = -1; 
    BindData(); 
} 

Answer 3

相反的boundfiled，我更喜歡使用TemplateField怎麼把它簡單。

測試示例代碼：從頁腳添加新的記錄，並更新選定行

默認。ASPX：

<asp:GridView ID="gvstatus" runat="server" AutoGenerateColumns="False" 
      CellPadding="4" ForeColor="#333333" GridLines="None" 
      onrowcancelingedit="gvstatus_RowCancelingEdit" 
      onrowediting="gvstatus_RowEditing" onrowupdating="gvstatus_RowUpdating" 
      onselectedindexchanged="gvstatus_SelectedIndexChanged" ShowFooter="True" 
      onrowcommand="gvstatus_RowCommand" Width="600px" AllowPaging="True" 
      onpageindexchanging="gvstatus_PageIndexChanging"> 
      <Columns> 

<asp:TemplateField HeaderText="SrNo " HeaderStyle-HorizontalAlign="Left"> 
      <ItemTemplate> 
        <%# Container.DataItemIndex + 1 %> 
       </ItemTemplate> 
</asp:TemplateField> 

<asp:TemplateField HeaderText="ID" Visible="false"> 
     <ItemTemplate> 
     <asp:Label ID="lblid" runat="server" Text='<%# Bind("columnname_id") %>'> </asp:Label> 
    </ItemTemplate> 
</asp:TemplateField> 


<asp:TemplateField HeaderText="EmpName"> 
     <ItemTemplate> 
     <asp:Label ID="lblEmpName" runat="server" Text='<%# Bind("columnname_EmpName") %>'></asp:Label> 
     </ItemTemplate> 
     <EditItemTemplate> 
      <asp:TextBox ID="txtEmpName" runat="server" Text='<%# Bind("columnname_EmpName") %>'></asp:TextBox> 
     </EditItemTemplate> 
     <FooterTemplate> 
       <asp:TextBox ID="txtfEmpName" runat="server"></asp:TextBox> 
     </FooterTemplate> 
</asp:TemplateField> 

<asp:TemplateField HeaderText="empSalary" > 
     <ItemTemplate> 
      <asp:Label ID="lblempSalary" runat="server" Text='<%# Bind("columnname_EmpSalary") %>'></asp:Label> 
     </ItemTemplate> 
     <EditItemTemplate> 
      <asp:TextBox ID="txtempSalary" runat="server" Text='<%# Bind("columnname_EmpSalary") %>'></asp:TextBox> 
     </EditItemTemplate> 
     <FooterTemplate> 
      <asp:TextBox ID="txtfempSalary" runat="server" ></asp:TextBox> 
     </FooterTemplate> 
</asp:TemplateField> 

<asp:TemplateField ShowHeader="False" ItemStyle-Width="190px"> 
     <ItemTemplate> 
      <asp:Button ID="btnedit" runat="server" CausesValidation="False" 
          CommandName="Edit" Text="Edit"></asp:Button> 
      </ItemTemplate> 
      <EditItemTemplate> 
       <asp:Button ID="btnupdate" runat="server" CausesValidation="True" 
          CommandName="Update" Text="Update"></asp:Button> 
         &nbsp;<asp:Button ID="btncancel" runat="server" CausesValidation="False" 
          CommandName="Cancel" Text="Cancel"></asp:Button> 
     </EditItemTemplate> 
     <FooterTemplate> 
      <asp:Button ID="btnadd" runat="server" Text="Add" CommandName="Add" /> 
     </FooterTemplate> 
</asp:TemplateField> 
      </Columns> 
      <PagerStyle BackColor="#A86E07" ForeColor="White" HorizontalAlign="Center" /> 
      <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" /> 
      <HeaderStyle BackColor="#A86E07" Font-Bold="True" ForeColor="White" /> 
     <EditRowStyle BackColor="#d9d9d9" /> 
    <AlternatingRowStyle BackColor="White" ForeColor="#A86E07" /> 
</asp:GridView> 

代碼隱藏：

protected void Page_Load(object sender, EventArgs e) 
    { 
     if (!Page.IsPostBack) 
     { 
     gvBind(); //Bind gridview 
     } 
    } 

public void gvBind() 
{ 
    SqlDataAdapter dap = new SqlDataAdapter("select id, empName,empSalary from myTable", conn); 
    DataSet ds = new DataSet(); 
    dap.Fill(ds); 
    gvstatus.DataSource = ds.Tables[0]; 
    gvstatus.DataBind(); 
} 

---

protected void gvstatus_RowUpdating(object sender, GridViewUpdateEventArgs e) 
    { 
     //Update the select row from girdview 
     lblmsg.Text = ""; 
     try 
     { 
      GridViewRow row = (GridViewRow)gvstatus.Rows[e.RowIndex]; 
      Label lblid = (Label)gvstatus.Rows[e.RowIndex].FindControl("lblid"); 
      TextBox txtname = (TextBox)gvstatus.Rows[e.RowIndex].FindControl("txtEmpName"); 
      TextBox txtSalary = (TextBox)gvstatus.Rows[e.RowIndex].FindControl("txtempSalary"); 
      string empName = txtname.Text; 
      string empSalary = txtSalary.Text; 
      string lblID=lblid.Text; 
      int result = UpdateQuery(empName, empSalary,lblID); 
      if (result > 0) 
      { 
       lblmsg.Text = "Record is updated successfully."; 
      } 
      gvstatus.EditIndex = -1; 
      gvBind(); 
     } 
     catch (Exception ae) 
     { 
      Response.Write(ae.Message); 
     } 

    } 

---

protected void gvstatus_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) 
    { 
     gvstatus.EditIndex = -1; 
     gvBind(); 
    } 
protected void gvstatus_RowEditing(object sender, GridViewEditEventArgs e) 
    { 
     lblmsg.Text = ""; 
     gvstatus.EditIndex = e.NewEditIndex; 
     gvBind(); 
    } 

    protected void gvstatus_RowCommand(object sender, GridViewCommandEventArgs e) 
    { 
     //Add new record to database form girdview footer 
     if (e.CommandName == "Add") 
     { 
      string empName = ((TextBox)gvstatus.FooterRow.FindControl("txtfempName")).Text; 
      string empSalry = ((TextBox)gvstatus.FooterRow.FindControl("txtfempSalary")).Text; 
      int result = InsertNewRecord(empName, empSalry); 
      if (result > 0) 
      { 
       lblmsg.Text = "Record is added successfully."; 
      } 
      gvstatus.EditIndex = -1; 
      gvBind(); 

     } 
    } 

---

public void UpdateQuery(string empName, string empSalary, string lblID) 
    { 
     SqlCommand cmd = new SqlCommand("update myTable set empName='" + empName + "',empSalary='" + empSalary + "' where id='" + lblID + "'", conn); 
     conn.Open(); 
     int temp = cmd.ExecuteNonQuery(); 
     conn.Close(); 
     return temp; 
    } 


public void InsertNewRecord(string empName, string empSalary) 
    { 
     SqlCommand cmd = new SqlCommand("your insert query ", conn); 
     conn.Open(); 
     int temp = cmd.ExecuteNonQuery(); 
     conn.Close(); 
     return temp; 
    } 

http://satindersinght.blogspot.in/2012/08/how-to-addupdate-record-using-gridview.html

馬克的答案，如果你發現它有幫助:)