HOW TO：自訂 Windows Form DataGridView 控制項中的資料格式
下列程式碼範例示範如何實作 DataGridView.CellFormatting 事件的處理常式，此事件會依據資料行和值來變更顯示儲存格的方式。
包含負數的 Balance 資料行中的儲存格會顯示紅色背景。 您也可以用貨幣形式格式化這些儲存格，在負數周圍顯示括號。 如需詳細資訊，請參閱 HOW TO：格式化 Windows Form DataGridView 控制項中的資料。
Priority 資料行中的儲存格會顯示影像，以代替對應的文字儲存格值。 DataGridViewCellFormattingEventArgs 的 Value 是用來取得文字儲存格值以及設定對應的影像顯示值。
範例
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Public Class Form1
Inherits Form
Private WithEvents dataGridView1 As New DataGridView()
Private highPriImage As Bitmap
Private mediumPriImage As Bitmap
Private lowPriImage As Bitmap
Public Sub New()
' Initialize the images.
Try
highPriImage = New Bitmap("highPri.bmp")
mediumPriImage = New Bitmap("mediumPri.bmp")
lowPriImage = New Bitmap("lowPri.bmp")
Catch ex As ArgumentException
MessageBox.Show("The Priority column requires Bitmap images" & _
"named highPri.bmp, mediumPri.bmp, and lowPri.bmp " & _
"residing in the same directory as the executable file.")
End Try
' Initialize the DataGridView.
With dataGridView1
.Dock = DockStyle.Fill
.AllowUserToAddRows = False
.Columns.AddRange( _
New DataGridViewTextBoxColumn(), _
New DataGridViewImageColumn())
.Columns(0).Name = "Balance"
.Columns(1).Name = "Priority"
.Rows.Add("-100", "high")
.Rows.Add("0", "medium")
.Rows.Add("100", "low")
End With
Me.Controls.Add(dataGridView1)
End Sub
' Changes how cells are displayed depending on their columns and values.
Private Sub dataGridView1_CellFormatting(ByVal sender As Object, _
ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) _
Handles dataGridView1.CellFormatting
' Set the background to red for negative values in the Balance column.
If dataGridView1.Columns(e.ColumnIndex).Name.Equals("Balance") Then
'Dim intValue As Int32
If CInt(e.Value) < 0 Then
'if Int32.TryParse((String)e.Value, out intValue) &&
' (intValue < 0))
e.CellStyle.BackColor = Color.Red
e.CellStyle.SelectionBackColor = Color.DarkRed
End If
End If
' Replace string values in the Priority column with images.
If dataGridView1.Columns(e.ColumnIndex).Name.Equals("Priority") Then
' Ensure that the value is a string.
Dim stringValue As String = TryCast(e.Value, String)
If stringValue Is Nothing Then Return
' Set the cell ToolTip to the text value.
Dim cell As DataGridViewCell = _
dataGridView1(e.ColumnIndex, e.RowIndex)
cell.ToolTipText = stringValue
' Replace the string value with the image value.
Select Case stringValue
Case "high"
e.Value = highPriImage
Case "medium"
e.Value = mediumPriImage
Case "low"
e.Value = lowPriImage
End Select
End If
End Sub
Public Sub Main()
Application.Run(New Form1())
End Sub
End Class
using System;
using System.Drawing;
using System.Windows.Forms;
public class Form1 : Form
{
private DataGridView dataGridView1 = new DataGridView();
private Bitmap highPriImage;
private Bitmap mediumPriImage;
private Bitmap lowPriImage;
public Form1()
{
// Initialize the images.
try
{
highPriImage = new Bitmap("highPri.bmp");
mediumPriImage = new Bitmap("mediumPri.bmp");
lowPriImage = new Bitmap("lowPri.bmp");
}
catch (ArgumentException)
{
MessageBox.Show("The Priority column requires Bitmap images " +
"named highPri.bmp, mediumPri.bmp, and lowPri.bmp " +
"residing in the same directory as the executable file.");
}
// Initialize the DataGridView.
dataGridView1.Dock = DockStyle.Fill;
dataGridView1.AllowUserToAddRows = false;
dataGridView1.Columns.AddRange(
new DataGridViewTextBoxColumn(),
new DataGridViewImageColumn());
dataGridView1.Columns[0].Name = "Balance";
dataGridView1.Columns[1].Name = "Priority";
dataGridView1.Rows.Add("-100", "high");
dataGridView1.Rows.Add("0", "medium");
dataGridView1.Rows.Add("100", "low");
dataGridView1.CellFormatting +=
new System.Windows.Forms.DataGridViewCellFormattingEventHandler(
this.dataGridView1_CellFormatting);
this.Controls.Add(dataGridView1);
}
// Changes how cells are displayed depending on their columns and values.
private void dataGridView1_CellFormatting(object sender,
System.Windows.Forms.DataGridViewCellFormattingEventArgs e)
{
// Set the background to red for negative values in the Balance column.
if (dataGridView1.Columns[e.ColumnIndex].Name.Equals("Balance"))
{
Int32 intValue;
if (Int32.TryParse((String)e.Value, out intValue) &&
(intValue < 0))
{
e.CellStyle.BackColor = Color.Red;
e.CellStyle.SelectionBackColor = Color.DarkRed;
}
}
// Replace string values in the Priority column with images.
if (dataGridView1.Columns[e.ColumnIndex].Name.Equals("Priority"))
{
// Ensure that the value is a string.
String stringValue = e.Value as string;
if (stringValue == null) return;
// Set the cell ToolTip to the text value.
DataGridViewCell cell = dataGridView1[e.ColumnIndex, e.RowIndex];
cell.ToolTipText = stringValue;
// Replace the string value with the image value.
switch (stringValue)
{
case "high":
e.Value = highPriImage;
break;
case "medium":
e.Value = mediumPriImage;
break;
case "low":
e.Value = lowPriImage;
break;
}
}
}
public static void Main()
{
Application.Run(new Form1());
}
}
編譯程式碼
這項範例需要：
System、System.Drawing 和 System.Windows.Forms 組件的參考。
名為 highPri.bmp、mediumPri.bmp 和 lowPri.bmp 的 Bitmap 影像位於與可執行檔相同的目錄中。
如需從 Visual Basic 或 Visual C# 的命令列建置這個範例的詳細資訊，請參閱從命令列建置 (Visual Basic) 或使用 csc.exe 建置命令列。 您也可以透過將程式碼貼入新的專案，在 Visual Studio 中建置此範例。 如需詳細資訊，請參閱HOW TO：使用 Visual Studio 編譯及執行完整的 Windows Form 程式碼範例 和 HOW TO：使用 Visual Studio 編譯及執行完整的 Windows Form 程式碼範例 和 HOW TO：使用 Visual Studio 編譯及執行完整的 Windows Form 程式碼範例 和 HOW TO：使用 Visual Studio 編譯及執行完整的 Windows Form 程式碼範例 和 如何：使用 Visual Studio 編譯及執行完整的 Windows Form 程式碼範例.
請參閱
工作
HOW TO：格式化 Windows Form DataGridView 控制項中的資料
參考
DataGridViewBand.DefaultCellStyle
概念
Windows Form DataGridView 控制項中的儲存格樣式
Windows Form DataGridView 控制項中的資料格式