Question

这里我有一个包含数据网格视图和三个按钮的表单，即编辑，删除和返回。当我加载表单时，它在数据网格中显示正确的数据，但假设我通过单击编辑或删除按钮来编辑或删除记录，并且在执行这些操作后此表单到达前景时，数据网格视图不是' t显示更新的数据。欢迎任何帮助..... 注意 - 当我单击编辑或删除按钮时，此表单不会关闭它只是进入后台。我的代码如下： -

namespace RDASMS
{
    public partial class LoginDb : Form
    {
        DataTable dt = new DataTable();
        public LoginDb()
        {
            InitializeComponent();
        }

        //OleDbConnection vcon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\workspace\RDASMS\RDASMS\rdadb.mdb");

        public Form ReferToAdmin
        {
            get;
            set;
        }

        private void LoginDb_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'rdadbDataSet1.login' table. You can move, or remove it, as needed.
           // this.loginTableAdapter.Fill(this.rdadbDataSet1.login);
            // TODO: This line of code loads data into the 'rdadbDataSet.login' table. You can move, or remove it, as needed.
            //this.loginTableAdapter.Fill(this.rdadbDataSet.login);

            MyOleDbConnection.Open();
            DataSet ds = new DataSet();
            //DataTable dt = new DataTable();
            ds.Tables.Add(dt);
            OleDbDataAdapter da = new OleDbDataAdapter();
            da = new OleDbDataAdapter("select * from login", MyOleDbConnection.vcon);
            /*da.Fill(dt);
            logindb_dataGridView.DataSource = dt.DefaultView;*/
            da.Fill(dt);
            logindb_dataGridView.DataSource = dt;
            logindb_dataGridView.AutoResizeColumns();
            MyOleDbConnection.Close();
        }

        private void logindb_panel_Paint(object sender, PaintEventArgs e)
        {

        }

        private void logindbback_Click(object sender, EventArgs e)
        {
            this.Close();
            this.ReferToAdmin.Show();
        }

        private void logindbdelete_Click(object sender, EventArgs e)
        {
            DeleteRecord dr = new DeleteRecord();
            dr.ReferToLogindb = this;
            dr.Show();
            this.Hide();
        }

        private void logindbedit_Click(object sender, EventArgs e)
        {
            EditRecord er = new EditRecord();
            er.ReferToLogindb = this;
            er.Show();
            this.Hide();
        }
    }
}

Answer 1

您可以使用表单的“Activated”事件。这样，每次激活表单时（在您的情况下“到达前台”）数据都将更新：

public LoginDb()
    {
        InitializeComponent();
        this.Activated += new EventHandler(LoginDb_Activated);
    }

    void LoginDb_Activated(object sender, EventArgs e)
    {
        this.BindData();
    }

    private void BindData()
    {
        MyOleDbConnection.Open();
        DataSet ds = new DataSet();
        //DataTable dt = new DataTable();
        ds.Tables.Add(dt);
        OleDbDataAdapter da = new OleDbDataAdapter();
        da = new OleDbDataAdapter("select * from login", MyOleDbConnection.vcon);
        /*da.Fill(dt);
        logindb_dataGridView.DataSource = dt.DefaultView;*/
        da.Fill(dt);
        logindb_dataGridView.DataSource = dt;
        logindb_dataGridView.AutoResizeColumns();
        MyOleDbConnection.Close();
    }

请注意，这可能会导致您计划对数据库进行更多调用。您可以通过检查数据是否被操作（使用操纵类的属性）来检查其中一个“编辑按钮”是否被点击，甚至更好，从而避免这种情况。

如何在将表单从背景变为前景时更新数据网格视图？

1 个答案: