生成动态按钮 [英] Generating Dynamic Buttons

问题描述

实际上我从数据库生成2个按钮（汉堡，冰淇淋）如果我点击汉堡按钮只需要汉堡项目如鸡肉汉堡，蔬菜汉堡，如果我们点击冰淇淋按钮只有冰淇淋像香草草莓应该有来吧，但在我的程序中，如果我点击冰淇淋只有冰淇淋项目好了，如果我再次按汉堡除了冰淇淋汉堡项目也来了，请帮助我

actually i generated 2 buttons(Burger,Ice Cream) from database if i Click the Burger button only i need Burger Items like Chicken Burger,Veg Burger,if we click the Ice cream button only Ice creams like vanilla strawberry should have to come, but in my program if i click ice cream only ice cream items coming fine, if i again i pressed burger in addition to ice cream burger items also coming, please help me

private void btnRetreive_Click(object sender, EventArgs e)
        {          
            string str = sender.ToString();
            string Category = str.Replace("System.Windows.Forms.Button, Text: ", "");
            strCon = GetConnectionString();
            OleDbConnection objCon = new OleDbConnection(strCon);
            objCon.Open();
            string query = "Select count(*) from tblProduct where Category = '" + Category + "'";
            OleDbCommand com = new OleDbCommand(query, objCon);
            int count = Convert.ToInt32(com.ExecuteScalar());
            for (int i = 0; i < count; i++)
            {
                string Qry = "Select SubCategory from tblProduct where Category = '"+ Category +"'  ";
                OleDbDataAdapter adpter = new OleDbDataAdapter(Qry, objCon);
                DataTable dt = new DataTable();
                adpter.Fill(dt);

                Button b = new Button();

                b.Name = dt.Rows[i]["SubCategory"].ToString();
                b.Text = dt.Rows[i]["SubCategory"].ToString();

                b.ForeColor = Color.DarkBlue;
                b.BackColor = Color.Honeydew;
                b.Width = 150;


                b.Click += new EventHandler(btnRetreive1_Click);

               
                    b.Location = new Point((400+(i*10)), (i * 40));
                    this.tableLayoutPanel1.Controls.Add(b);                
            }
        }
        private void btnRetreive1_Click(object sender, EventArgs e)
        {   
            string strGetProductName;
            strGetProductName = sender.ToString();
            strGetProductName = strGetProductName.Replace("System.Windows.Forms.Button, Text: ", "");
         
            strCon = GetConnectionString();
            OleDbConnection objCon = new OleDbConnection(strCon);
            string Query = "Select Category,SubCategory,Rate,Qty from tblProduct where SubCategory ='" + strGetProductName + "' ";
            objCon.Open();
            OleDbDataAdapter adpter = new OleDbDataAdapter(Query, objCon);
            DataTable dt = new DataTable();
            dt.Clear();
            adpter.Fill(dt);
            objCon.Close();
            dataGridView1.DataSource = dt;
         }

推荐答案

好吧，我并不感到惊讶。您不会从TableLayoutPanel befoer中删除任何添加新按钮的按钮 - 您只需添加新项目。因此，如果他们选择一个类别并添加了一些按钮，那么就永远不要离开......



另外，我建议左右？看看你的btnRetreive1_Click方法：那太可怕了！

试试这个：

Well, I'm not surprised. You don't remove any buttons from your TableLayoutPanel befoer you add new ones - you just add the new items. so if they select a category and you add teh buttons, then never go away...

Plus, cal I make a suggestion or so? Look at your btnRetreive1_Click method: that's pretty horrible!
Try this:

private void btnRetreive1_Click(object sender, EventArgs e)
{
    Button b = sender as Button;
    if (b != null)
    {
        string strGetProductName = b.Text;

        strCon = GetConnectionString();
        OleDbConnection objCon = new OleDbConnection(strCon);
        string Query = "Select Category,SubCategory,Rate,Qty from tblProduct where SubCategory ='" + strGetProductName + "' ";
        objCon.Open();
        OleDbDataAdapter adpter = new OleDbDataAdapter(Query, objCon);
        DataTable dt = new DataTable();
        adpter.Fill(dt);
        objCon.Close();
        dataGridView1.DataSource = dt;
     }
 }

请不要这样做数据库访问！不要连接字符串以构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。请改用参数化查询。

And please, don't do DB accesses like that! Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.

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