Question

这是一个演示项目。

我想要实现的是，当单击一个按钮时，它将检查某些条件，然后将行插入Datagridview。

我需要再次插入行中存在的行 datagridview，应用单选按钮条件（新行和更新）。

到目前为止，我已经取得了这么多成就。

private void button5_Click(object sender, EventArgs e)
    {
        if (button5.Text == "")
        {
            MessageBox.Show("No Value Assigned");
        }
        else
        {
        MySqlConnection con = new MySqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["db"].ConnectionString);
        con.Open();
        MySqlDataAdapter dt = new MySqlDataAdapter();
        DataTable tt = new DataTable();
        BindingSource bs = new BindingSource();
        if (dataGridView1.RowCount > 0)
        {                
            bs = (BindingSource)dataGridView1.DataSource;
        }
        else
        { 
                if (radioButton1.Checked == true)
                {

                    string query = "SELECT type,priceS FROM service WHERE type='" + button5.Text + "'";
                    MySqlCommand cmd = new MySqlCommand(query, con);
                    dt.SelectCommand = cmd;                       
                }
                else if (radioButton2.Checked == true)
                {
                    string query = "SELECT type,priceM FROM service WHERE type='" + button5.Text + "'";
                    MySqlCommand cmd = new MySqlCommand(query, con);
                    dt.SelectCommand = cmd;

                }
                else if (radioButton3.Checked == true)
                {
                    string query = "SELECT type,priceL FROM service WHERE type='" + button5.Text + "'";
                    MySqlCommand cmd = new MySqlCommand(query, con);
                    dt.SelectCommand = cmd;                        
                }
            }            
        dt.Fill(tt);
        bs.DataSource = tt;
        dataGridView1.DataSource = bs;
        dt.Update(tt);
        con.Close();
        }            
    }

我可以插入第一行，但是当我尝试使用相同的按钮问题插入另一行时。

任何想法都表示赞赏。

private void button5_Click(object sender, EventArgs e)
    {
        if (button5.Text == "")
        {
            MessageBox.Show("No Value Assigned");
        }
        else
        {
        MySqlConnection con = new MySqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["db"].ConnectionString);
        con.Open();
        MySqlDataAdapter dt = new MySqlDataAdapter();
        DataTable tt = new DataTable();
        BindingSource bs = new BindingSource();
        if (radioButton1.Checked == true)
        {

            string query = "SELECT type,priceS FROM service WHERE type='" + button5.Text + "'";
            MySqlCommand cmd = new MySqlCommand(query, con);
            dt.SelectCommand = cmd;
        }
        else if (radioButton2.Checked == true)
        {
            string query = "SELECT type,priceM FROM service WHERE type='" + button5.Text + "'";
            MySqlCommand cmd = new MySqlCommand(query, con);
            dt.SelectCommand = cmd;

        }
        else if (radioButton3.Checked == true)
        {
            string query = "SELECT type,priceL FROM service WHERE type='" + button5.Text + "'";
            MySqlCommand cmd = new MySqlCommand(query, con);
            dt.SelectCommand = cmd;
        }
        if (dataGridView1.RowCount > 0)
        {
            tt.Rows.Add(dataGridView1);
            dt.Fill(tt);
            bs.DataSource = tt;
            dataGridView1.DataSource = bs;
            dt.Update(tt);
            con.Close();
        }
        else
        {
            dt.Fill(tt);
            bs.DataSource = tt;
            dataGridView1.DataSource = bs;
            dt.Update(tt);
            con.Close();
        }
        }            
    }

这是我的另一种方法，但我得到了错误：输入数组长于此表中的列数。我在哪里弄错了？

Answer 1

嗯，每个按钮单击都会清除数据表...也许用其他函数定义数据表并手动将行添加到数据表中？

Answer 2

我将在评论中向您展示代码中的一些代码和解释的示例，请看一下：

首先，构建以下表格：

这是它背后的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            // Initially your DataGridView will not have a DataSource to display your data so you need
            // to define a DataTable that will be used as the DataSource for you DataGridView
            var dt = new DataTable();
            // Add the desired columns to it, with their headers and data types
            dt.Columns.Add(new DataColumn("Id", typeof(int)));
            dt.Columns.Add(new DataColumn("Description", typeof(string)));

            // You can add new rows to your DataTable using the DataTable object itself
            // in order to create DataRows with the exact DataColumns required for that DataTable
            var newRow = dt.NewRow();
            newRow["Id"] = 1;
            newRow["Description"] = "Desc 1";
            // And then you simply add this new row to your DataTable
            dt.Rows.Add(newRow);

            newRow = dt.NewRow();
            newRow["Id"] = 2;
            newRow["Description"] = "Desc 2";
            dt.Rows.Add(newRow);

            newRow = dt.NewRow();
            newRow["Id"] = 3;
            newRow["Description"] = "Desc 3";
            dt.Rows.Add(newRow);

            // By the end you set the DataSource property of your DataGridView
            // assigning to it the DataTable you created
            dataGridView1.DataSource = dt;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            // In order to add new rows to your DataGridView with the current DataTable
            // you simply need to take it back from the DataGridView.DataSource property by casting it
            // to a DataTable again
            var dt = (DataTable)dataGridView1.DataSource;

            // And then you add the new rows in the same way that were shown in the Click event for button1
            var newRow = dt.NewRow();
            newRow["Id"] = 4;
            newRow["Description"] = "Desc 4";
            dt.Rows.Add(newRow);

            newRow = dt.NewRow();
            newRow["Id"] = 5;
            newRow["Description"] = "Desc 5";
            dt.Rows.Add(newRow);
        }
    }
}

如何在C＃中的同一Datagridview中添加现有行的新Datagridview行

2 个答案: