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Cara: Menangani Kesalahan yang Terjadi Selama Entri Data di Formulir Windows Kontrol DataGridView

  • Artikel

Contoh kode berikut menunjukkan cara menggunakan DataGridView kontrol untuk melaporkan kesalahan entri data kepada pengguna.

Untuk penjelasan lengkap tentang contoh kode ini, lihat Panduan: Menangani Kesalahan yang Terjadi Selama Entri Data di Formulir Windows Kontrol DataGridView.

Contoh

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;

public class Form1 : System.Windows.Forms.Form
{
    private DataGridView dataGridView1 = new DataGridView();
    private BindingSource bindingSource1 = new BindingSource();

    public Form1()
    {
        // Initialize the form.
        this.dataGridView1.Dock = DockStyle.Fill;
        this.Controls.Add(dataGridView1);
        this.Load += new EventHandler(Form1_Load);
    }

    private void Form1_Load(System.Object sender, System.EventArgs e)
    {
        // Attach the DataError event to the corresponding event handler.
        this.dataGridView1.DataError +=
            new DataGridViewDataErrorEventHandler(dataGridView1_DataError);

        // Initialize the BindingSource and bind the DataGridView to it.
        bindingSource1.DataSource = GetData("select * from Customers");
        this.dataGridView1.DataSource = bindingSource1;
        this.dataGridView1.AutoResizeColumns(
            DataGridViewAutoSizeColumnsMode.AllCellsExceptHeader);
    }

    private void dataGridView1_DataError(object sender,
        DataGridViewDataErrorEventArgs e)
    {
        // If the data source raises an exception when a cell value is
        // commited, display an error message.
        if (e.Exception != null &&
            e.Context == DataGridViewDataErrorContexts.Commit)
        {
            MessageBox.Show("CustomerID value must be unique.");
        }
    }

    private static DataTable GetData(string selectCommand)
    {
        string connectionString =
            "Integrated Security=SSPI;Persist Security Info=False;" +
            "Initial Catalog=Northwind;Data Source=localhost;Packet Size=4096";

        // Connect to the database and fill a data table, including the
        // schema information that contains the CustomerID column
        // constraint.
        SqlDataAdapter adapter =
            new SqlDataAdapter(selectCommand, connectionString);
        DataTable data = new DataTable();
        data.Locale = System.Globalization.CultureInfo.InvariantCulture;
        adapter.Fill(data);
        adapter.FillSchema(data, SchemaType.Source);

        return data;
    }

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new Form1());
    }
}

Imports System.Data
Imports System.Data.SqlClient
Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form

    Private WithEvents dataGridView1 As New DataGridView()
    Private bindingSource1 As New BindingSource()

    Public Sub New()

        ' Initialize the form.
        Me.dataGridView1.Dock = DockStyle.Fill
        Me.Controls.Add(dataGridView1)

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Me.Load

        ' Initialize the BindingSource and bind the DataGridView to it.
        bindingSource1.DataSource = GetData("select * from Customers")
        Me.dataGridView1.DataSource = bindingSource1
        Me.dataGridView1.AutoResizeColumns( _
            DataGridViewAutoSizeColumnsMode.AllCellsExceptHeader)

    End Sub

    Private Sub dataGridView1_DataError(ByVal sender As Object, _
        ByVal e As DataGridViewDataErrorEventArgs) _
        Handles dataGridView1.DataError

        ' If the data source raises an exception when a cell value is 
        ' commited, display an error message.
        If e.Exception IsNot Nothing AndAlso _
            e.Context = DataGridViewDataErrorContexts.Commit Then

            MessageBox.Show("CustomerID value must be unique.")

        End If

    End Sub

    Private Shared Function GetData(ByVal selectCommand As String) As DataTable

        Dim connectionString As String = _
            "Integrated Security=SSPI;Persist Security Info=False;" + _
            "Initial Catalog=Northwind;Data Source=localhost;Packet Size=4096"

        ' Connect to the database and fill a data table, including the 
        ' schema information that contains the CustomerID column 
        ' constraint.
        Dim adapter As New SqlDataAdapter(selectCommand, connectionString)
        Dim data As New DataTable()
        data.Locale = System.Globalization.CultureInfo.InvariantCulture
        adapter.Fill(data)
        adapter.FillSchema(data, SchemaType.Source)

        Return data

    End Function

    <STAThread()> _
    Shared Sub Main()
        Application.EnableVisualStyles()
        Application.Run(New Form1())
    End Sub

End Class

Mengompilasi Kode

Contoh ini membutuhkan:

  • Referensi ke rakitan System, System.Data, System.Windows.Forms, dan System.XML.

Keamanan .NET Framework

Menyimpan informasi sensitif, seperti kata sandi, dalam string koneksi dapat memengaruhi keamanan aplikasi Anda. Menggunakan Autentikasi Windows (juga dikenal sebagai keamanan terintegrasi) adalah cara yang lebih aman untuk mengontrol akses ke database. Untuk informasi lebih lengkap, lihat Melindungi Informasi Koneksi.

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