操作說明:驗證 Windows Forms DataGridView 控制項中的資料
下列程式碼範例示範如何驗證使用者輸入 DataGridView 控制項的資料。 在此範例中,會填入來自 Northwind 範例資料庫 Customers
資料表的資料列到 DataGridView。 當使用者編輯 CompanyName
資料行中的儲存格時,會檢查是否為空白以測試其值的有效性。 如果 CellValidating 事件的事件處理常式發現此值為空字串,則直到使用者輸入非空白字串之前,DataGridView 會讓使用者不能離開儲存格。
如需這個程式碼範例的完整說明,請參閱逐步解說:驗證 Windows Form DataGridView 控制項中的資料。
範例
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);
this.Text = "DataGridView validation demo (disallows empty CompanyName)";
}
private void Form1_Load(System.Object sender, System.EventArgs e)
{
// Attach DataGridView events to the corresponding event handlers.
this.dataGridView1.CellValidating += new
DataGridViewCellValidatingEventHandler(dataGridView1_CellValidating);
this.dataGridView1.CellEndEdit += new
DataGridViewCellEventHandler(dataGridView1_CellEndEdit);
// 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_CellValidating(object sender,
DataGridViewCellValidatingEventArgs e)
{
string headerText =
dataGridView1.Columns[e.ColumnIndex].HeaderText;
// Abort validation if cell is not in the CompanyName column.
if (!headerText.Equals("CompanyName")) return;
// Confirm that the cell is not empty.
if (string.IsNullOrEmpty(e.FormattedValue.ToString()))
{
dataGridView1.Rows[e.RowIndex].ErrorText =
"Company Name must not be empty";
e.Cancel = true;
}
}
void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
// Clear the row error in case the user presses ESC.
dataGridView1.Rows[e.RowIndex].ErrorText = String.Empty;
}
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.
SqlDataAdapter adapter =
new SqlDataAdapter(selectCommand, connectionString);
DataTable data = new DataTable();
data.Locale = System.Globalization.CultureInfo.InvariantCulture;
adapter.Fill(data);
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)
Me.Text = "DataGridView validation demo (disallows empty CompanyName)"
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_CellValidating(ByVal sender As Object, _
ByVal e As DataGridViewCellValidatingEventArgs) _
Handles dataGridView1.CellValidating
Dim headerText As String = _
dataGridView1.Columns(e.ColumnIndex).HeaderText
' Abort validation if cell is not in the CompanyName column.
If Not headerText.Equals("CompanyName") Then Return
' Confirm that the cell is not empty.
If (String.IsNullOrEmpty(e.FormattedValue.ToString())) Then
dataGridView1.Rows(e.RowIndex).ErrorText = _
"Company Name must not be empty"
e.Cancel = True
End If
End Sub
Private Sub dataGridView1_CellEndEdit(ByVal sender As Object, _
ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _
Handles dataGridView1.CellEndEdit
' Clear the row error in case the user presses ESC.
dataGridView1.Rows(e.RowIndex).ErrorText = String.Empty
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.
Dim adapter As New SqlDataAdapter(selectCommand, connectionString)
Dim data As New DataTable()
data.Locale = System.Globalization.CultureInfo.InvariantCulture
adapter.Fill(data)
Return data
End Function
<STAThread()> _
Shared Sub Main()
Application.EnableVisualStyles()
Application.Run(New Form1())
End Sub
End Class
編譯程式碼
這個範例需要:
- System、System.Data、System.Windows.Forms 和 System.XML 組件的參考。
.NET Framework 安全性
在連接字串內儲存機密資訊 (例如密碼) 會影響應用程式的安全性。 使用 Windows 驗證 (也稱為整合式安全性) 是控制資料庫存取的更安全方式。 如需詳細資訊,請參閱保護連線資訊。
另請參閱
意見反應
https://aka.ms/ContentUserFeedback。
即將登場:在 2024 年,我們將逐步淘汰 GitHub 問題作為內容的意見反應機制,並將它取代為新的意見反應系統。 如需詳細資訊,請參閱:提交並檢視相關的意見反應