asp.net C中按钮单击事件的文本框值不会改变＃

Question

I'm stuck with a problem where i can't get the values of any control not just textboxes in button click event so here is the scenario, You can skip it and just can look into my button click event

Page product is performing 2 operations

• Create
• Update

When a user clicks Edit on GridView in updpage It will redirects it to Product Page to update, Same page is performing Create product operation too, So when I receive QueryString value I'll update the product table and when I won't so I just perform Create operation.

---

Now I'm stuck when there is no QueryString value so textboxes are updating with a new values but when there is, so they don't give me a new value.

Here is my code

On pageLoad Event I'm filling text boxes with there respective values where there is an update operation

protected void Page_Load(object sender, EventArgs e)
{

    if (Request.QueryString["update"] !=null)
    {
        if (!Page.IsPostBack)
        {
            bindcategories();
            bindachievments();
            bindbrands();
        }
        int id = int.Parse(Request.QueryString["update"]);
        string query = "SELECT * FROM ProductView WHERE id = " + id.ToString();
        DataTable dtupd = new DataTable();
        dtupd = param.All_data(query);

        string name = "",available="",category="",brand="",achievement="",image="";
        decimal price=0;
        int unit = 0;

        foreach (DataRow row in dtupd.Rows)
        {
             name = row.Field<string>("product_name");
             price = row.Field<decimal>("price");
             unit = row.Field<int>("unit");
             image = row.Field<string>("product_image");
             available = row.Field<string>("available");
             category = row.Field<string>("category_name");
             brand = row.Field<string>("brand_name");
             achievement = row.Field<string>("achievement");
        }
        txt_name.Text = name;
        txt_price.Text = price.ToString();
        txt_unit.Text = unit.ToString();
        product_image.ImageUrl = "../" + image;

        dd_available.ClearSelection();
        dd_available.SelectedValue = available;

        dd_category.ClearSelection();
        dd_category.Items.FindByText(category).Selected = true;

        dd_brand.ClearSelection();
        dd_brand.Items.FindByText(brand).Selected = true;

        dd_achievment.ClearSelection();
        dd_achievment.Items.FindByText(achievement).Selected = true;
        btn_Insert.Text = "Update Product";
    }
    else
    {
        if (!Page.IsPostBack)
        {
            bindcategories();
            bindbrands();
            bindachievments();
        }
        if (!FileUpload1.HasFile)
        {
            product_image.ImageUrl = "../assets/images/products/default.png";
        }

    }


}

Button event code

protected void btn_Insert_Click(object sender, EventArgs e)
{
    getpicture();
    SqlCommand cmd;
    string pathimage ="";
    if (pathimage == "")
    {
        pathimage = product_image.ImageUrl;
    }
    else
    {
        pathimage = ViewState["pathimage"].ToString();
    }

    if (Request.QueryString["update"] != null)
    {

        int id = int.Parse(Request.QueryString["update"]);
        string query = "UPDATE Products SET product_name=@PRODUCTNAME,price=@PRIZE,unit=@UNIT,product_image=@IMAGE,available=@AVAILABLE,product_category=@CATEGORY,product_brand=@BRAND,product_achv=@ACHIV WHERE id = @ID";
        cmd = new SqlCommand(query);
        txt_name.Text = "";
        cmd.Parameters.Add("@PRODUCTNAME", txt_name.Text);
        cmd.Parameters.Add("@PRIZE", txt_price.Text);
        cmd.Parameters.Add("@UNIT", txt_unit.Text);
        cmd.Parameters.Add("@IMAGE", pathimage);
        cmd.Parameters.Add("@AVAILABLE", dd_available.SelectedItem.ToString());
        cmd.Parameters.Add("@CATEGORY", dd_category.SelectedValue);
        cmd.Parameters.Add("@BRAND", dd_brand.SelectedValue);
        cmd.Parameters.Add("@ACHIV", dd_achievment.SelectedValue);
        cmd.Parameters.Add("@ID", id);
        param.InsertUpdateData(cmd);
    }
    else
    {
        string query = "INSERT INTO Products(product_name,price,unit,product_image,available,product_category,product_brand,product_achv) VALUES(@PRODUCTNAME,@PRIZE,@UNIT,@IMAGE,@AVAILABLE,@CATEGORY,@BRAND,@ACHIV)";
        cmd = new SqlCommand(query);
        cmd.Parameters.Add("@PRODUCTNAME", txt_name.Text);
        cmd.Parameters.Add("@PRIZE", txt_price.Text);
        cmd.Parameters.Add("@UNIT", txt_unit.Text);
        cmd.Parameters.Add("@IMAGE", pathimage);
        cmd.Parameters.Add("@AVAILABLE", dd_available.SelectedItem.ToString());
        cmd.Parameters.Add("@CATEGORY", dd_category.SelectedValue);
        cmd.Parameters.Add("@BRAND", dd_brand.SelectedValue);
        cmd.Parameters.Add("@ACHIV", dd_achievment.SelectedValue);
        param.InsertUpdateData(cmd);
    }

}

It is getpicture function used in btn_submit

private void getpicture()
{
    try
    {
        if (FileUpload1.PostedFile != null)
        {
            string FileName = Path.GetFileName(FileUpload1.PostedFile.FileName);
            string root = Server.MapPath("~");
            string path = root + "assets\\images\\products\\";
            FileUpload1.SaveAs(path + FileName);
            ViewState["pathimage"] = "/assets/images/products/" + FileName;
            this.product_image.ImageUrl = "../assets/images/products/upload.png";
        }
        else
        {
            Response.Write("Select an Image");
        }
    }
    catch (Exception ex)
    {
        Response.Write("Select an Image");
    }
}

Providing Data access layer Insert Update Data code too

public Boolean InsertUpdateData(SqlCommand cmd)
{
    String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["OnlineStoreConnectionString"].ConnectionString;
    SqlConnection con = new SqlConnection(strConnString);
    cmd.CommandType = CommandType.Text;
    cmd.Connection = con;
    try
    {
        con.Open();
        cmd.ExecuteNonQuery();
        System.Web.HttpContext.Current.Response.Write("Succed");
        return true;
    }

    catch (Exception ex)
    {
       System.Web.HttpContext.Current.Response.Write(ex.ToString());
       return false;
    }

    finally
    {
        con.Close();
        con.Dispose();
    }
}

Server Controls

   <div class="row">
    <div class="col-md-6">
        <asp:TextBox ID="txt_name" runat="server" CssClass="form-control" placeholder="Product Name"></asp:TextBox>
        <br />
        <asp:TextBox ID="txt_price" runat="server" CssClass="form-control" placeholder="Product Price"></asp:TextBox>
        <br />
        <asp:TextBox ID="txt_unit" runat="server" CssClass="form-control" placeholder="Product Unit"></asp:TextBox>
        <br />
        <asp:DropDownList ID="dd_available" runat="server" CssClass="form-control">
            <asp:ListItem>Is Product Available</asp:ListItem>
            <asp:ListItem>Available</asp:ListItem>
            <asp:ListItem>Not Avaliable</asp:ListItem>
        </asp:DropDownList>
        <br />
        <asp:DropDownList ID="dd_category" runat="server" CssClass="form-control"></asp:DropDownList>
        <br />
        <asp:DropDownList ID="dd_brand" runat="server" CssClass="form-control"></asp:DropDownList>
        <br />
        <asp:DropDownList ID="dd_achievment" runat="server" CssClass="form-control"></asp:DropDownList>
        <br />
    </div>
    <div class="col-md-2"></div>
    <div class="col-md-4">
        <asp:Image ID="product_image" runat="server"  style="height:231px;width:225px;" CssClass="form-control" />

        <asp:FileUpload ID="FileUpload1" runat="server"   onchange = "show_image(this);" />

    </div>

</div>
<br />
<div class="row">
    <div class="col-md-3 col-md-offset-6">
        <asp:Button ID="btn_Insert" runat="server" Text="Create Product" CssClass="btn btn-primary btn-lg" OnClick="btn_Insert_Click" />
    </div>
</div>

Before Clicking update button

Before clicking update button

After I updated text box values respectively and when click button Upload None of my server control value changes. Here it is

Watching local variable

But in case of Creating Product it works

Answer 1

Saad, i think the error is in the page_load event. If in your querystring the update param is not null, then you are always replacing the textboxes with the data of your DB. Your code should be like this

 protected void Page_Load(object sender, EventArgs e) { if (Request.QueryString["update"] !=null) { if (!Page.IsPostBack) { bindcategories(); bindachievments(); bindbrands(); int id = int.Parse(Request.QueryString["update"]); string query = "SELECT * FROM ProductView WHERE id = " + id.ToString(); DataTable dtupd = new DataTable(); dtupd = param.All_data(query); string name = "",available="",category="",brand="",achievement="",image=""; decimal price=0; int unit = 0; foreach (DataRow row in dtupd.Rows) { name = row.Field<string>("product_name"); price = row.Field<decimal>("price"); unit = row.Field<int>("unit"); image = row.Field<string>("product_image"); available = row.Field<string>("available"); category = row.Field<string>("category_name"); brand = row.Field<string>("brand_name"); achievement = row.Field<string>("achievement"); } txt_name.Text = name; txt_price.Text = price.ToString(); txt_unit.Text = unit.ToString(); product_image.ImageUrl = "../" + image; dd_available.ClearSelection(); dd_available.SelectedValue = available; dd_category.ClearSelection(); dd_category.Items.FindByText(category).Selected = true; dd_brand.ClearSelection(); dd_brand.Items.FindByText(brand).Selected = true; dd_achievment.ClearSelection(); dd_achievment.Items.FindByText(achievement).Selected = true; btn_Insert.Text = "Update Product"; } } else { if (!Page.IsPostBack) { bindcategories(); bindbrands(); bindachievments(); } if (!FileUpload1.HasFile) { product_image.ImageUrl = "../assets/images/products/default.png"; } } } 

Hope it helps...