如何在表单加载时从数据库更新 datagridview？

Question

我对 C# 和一般编码相当陌生。我已经查看了类似的问题，并没有太多的运气来解决这个问题。

我正在制作一个应用程序，将学生的出勤详细信息存储在数据库中的表格中。目前，当我运行它时，详细信息会从文本框添加到表格中。一个按钮会打开一个带有 datagridview 的单独表单，但其中的详细信息不会更新。如果我重新运行应用程序并打开第二个表单，则 datagridview 已更新。如何在应用程序运行时根据添加到表中的信息更新 datagridview？

这是向表格添加详细信息的代码

                using (SqlConnection sc = new SqlConnection())
                {
                    sc.ConnectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\corry\Desktop\StudentAttendanceBurton\Attendance.mdf;Integrated Security=True";
                    sc.Open();

                    using (SqlCommand com = sc.CreateCommand())
                    {
                        com.CommandText =
                          "insert into BUS102(\n" +
                          "  Name,\n" +
                          "  [Student ID],\n" +
                          "  Date)\n" +
                          "values(\n" +
                          "  @prm_Name,\n" +
                          "  @prm_Student_ID,\n" +
                          "  @prm_Date)";


                        com.Parameters.Add("@prm_Name", SqlDbType.NVarChar, 50).Value = student.Name;
                        com.Parameters.Add("@prm_Student_ID", SqlDbType.Int).Value = student.StudentID;
                        com.Parameters.Add("@prm_Date", SqlDbType.SmallDateTime).Value = student.Date;


                        com.ExecuteNonQuery();
                    }
                }

这是具有 datagridview 的表单的代码

public partial class AttendanceForm : Form

{

    public AttendanceForm()
    {
        InitializeComponent();
    }

    private void bUS102BindingNavigatorSaveItem_Click(object sender, EventArgs e)
    {
        this.Validate();
        this.bUS102BindingSource.EndEdit();
        this.tableAdapterManager.UpdateAll(this.attendanceDataSet);

    }

    private void AttendanceForm_Load(object sender, EventArgs e)
    {

        // TODO: This line of code loads data into the 'attendanceDataSet.BUS102' table. You can move, or remove it, as needed.
        this.bUS102TableAdapter.Fill(this.attendanceDataSet.BUS102);

    }
}

Answer 1

    public partial class Form1 : Form {
    private DataSet m_ds = new DataSet();

    public Form1() {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e) {
        using (SqlConnection conn = new SqlConnection(@"Data Source=YOURSql;Initial Catalog=YOURDB;Integrated Security=True")) {

            // set command
            SqlCommand cmd = new SqlCommand("SELECT * FROM YourTable", conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);

            conn.Open();
            da.Fill(m_ds);

            // bind data to dataGrid
            dataGridView1.DataSource = m_ds.Tables[0];

            // refresh Data
            dataGridView1.Refresh();
            conn.Close();
        }


    }

    private void cmdChangeData_Click(object sender, EventArgs e) {
        // add new row explicit 
        DataRow nr = m_ds.Tables[0].NewRow();
        nr[0] = "0000";
        nr[1] = "xxxx";

        // add new row to DataSet (just in memory, NOT TO DB)
        m_ds.Tables[0].Rows.Add(nr);

        // Refresh Data
        dataGridView1.Refresh();

    }
}

Answer 2

你必须刷新datagridview

this.dataGridView1.Refresh();