Como personalizar a formatação de dados no controle DataGridView dos Windows Forms

  • Artigo

O exemplo de código a seguir demonstra como implementar um manipulador para o evento que altera como as DataGridView.CellFormatting células são exibidas dependendo de suas colunas e valores.

As células na Balance coluna que contêm números negativos recebem um plano de fundo vermelho. Você também pode formatar essas células como moeda para exibir parênteses em torno de valores negativos. Para obter mais informações, consulte Como formatar dados no controle DataGridView do Windows Forms.

As células na Priority coluna exibem imagens no lugar dos valores de célula textual correspondentes. A Value propriedade do é usada para obter o valor da célula textual e para definir o valor de exibição da DataGridViewCellFormattingEventArgs imagem correspondente.

Exemplo

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());
    }
}

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

Compilando o código

Este exemplo requer:

  • Referências aos assemblies System, System.Drawing e System.Windows.Forms.

  • Bitmap imagens chamadas highPri.bmp, mediumPri.bmpe lowPri.bmp residindo no mesmo diretório que o arquivo executável.

Confira também