C# asp.net C中的按钮单击事件不会更改文本框值

我遇到了一个问题，我无法获取任何控件的值，而不仅仅是按钮单击事件中的文本框，所以这里是一个场景，您可以跳过它，只需查看我的按钮单击事件

页面产品正在执行2个操作

创造 使现代化 当用户在updpage中单击GridView上的编辑时，它将重定向到要更新的产品页面，同一页面也在执行创建产品操作，因此当我收到QueryString值时，我将更新产品表，当我不这样做时，我只执行创建操作

现在，当没有QueryString值时，我被卡住了，所以文本框会用新值更新，但当有值时，它们不会给我新值

这是我的密码

在pageLoad事件中，我用相应的值填充文本框 其中有一个更新操作

它是btn_submit中使用的getpicture函数

提供数据访问层并插入更新数据代码

服务器控件

单击“更新”按钮之前

在我分别更新了文本框值和单击“上载”按钮后，我的服务器控件值没有任何更改。给你

但在创建产品的情况下，它是有效的

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Saad，我认为错误在page_load事件中。如果查询字符串中的update参数不为null，则始终使用数据库的数据替换文本框。 您的代码应该是这样的

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希望它能帮助…

嗨。运行代码时是否出现错误？我们可以看到aspx页面中控件的位置吗？感谢您的帮助，是的，我找到了它并准备结束问题，但再次感谢您的回答，它也是正确的，因此我正在标记它：

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";
        }

    }


}

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);
    }

}

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");
    }
}

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();
    }
}

   <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>

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";
    }

}


}