DataGridViewButtonColumn Klass

Definition

public ref class DataGridViewButtonColumn : System::Windows::Forms::DataGridViewColumn

[System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewButtonColumn), "DataGridViewButtonColumn.bmp")]
public class DataGridViewButtonColumn : System.Windows.Forms.DataGridViewColumn

[System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)]
[System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewButtonColumn), "DataGridViewButtonColumn")]
public class DataGridViewButtonColumn : System.Windows.Forms.DataGridViewColumn

[System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewButtonColumn), "DataGridViewButtonColumn")]
public class DataGridViewButtonColumn : System.Windows.Forms.DataGridViewColumn

[<System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewButtonColumn), "DataGridViewButtonColumn.bmp")>]
type DataGridViewButtonColumn = class
    inherit DataGridViewColumn

[<System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)>]
[<System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewButtonColumn), "DataGridViewButtonColumn")>]
type DataGridViewButtonColumn = class
    inherit DataGridViewColumn

[<System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewButtonColumn), "DataGridViewButtonColumn")>]
type DataGridViewButtonColumn = class
    inherit DataGridViewColumn

Public Class DataGridViewButtonColumn
Inherits DataGridViewColumn

Arv

Object

DataGridViewElement

DataGridViewBand

DataGridViewColumn

DataGridViewButtonColumn

Attribut

ToolboxBitmapAttribute DynamicallyAccessedMembersAttribute

Exempel

Följande kodexempel visar hur du använder en DataGridViewButtonColumn för att utföra åtgärder på vissa rader. I det här exemplet avgör en DataGridView.CellClick händelsehanterare först om ett klick finns i en knappcell och hämtar sedan ett affärsobjekt som är associerat med raden. Det här exemplet är en del av ett större exempel i How to: Access Objects in a Windows Forms DataGridViewComboBoxCell Drop-Down List.

public class Form1 : Form
{
    private List<Employee> employees = new List<Employee>();
    private List<Task> tasks = new List<Task>();
    private Button reportButton = new Button();
    private DataGridView dataGridView1 = new DataGridView();

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

    public Form1()
    {
        dataGridView1.Dock = DockStyle.Fill;
        dataGridView1.AutoSizeColumnsMode = 
            DataGridViewAutoSizeColumnsMode.AllCells;
        reportButton.Text = "Generate Report";
        reportButton.Dock = DockStyle.Top;
        reportButton.Click += new EventHandler(reportButton_Click);

        Controls.Add(dataGridView1);
        Controls.Add(reportButton);
        Load += new EventHandler(Form1_Load);
        Text = "DataGridViewComboBoxColumn Demo";
    }

    // Initializes the data source and populates the DataGridView control.
    private void Form1_Load(object sender, EventArgs e)
    {
        PopulateLists();
        dataGridView1.AutoGenerateColumns = false;
        dataGridView1.DataSource = tasks;
        AddColumns();
    }

    // Populates the employees and tasks lists. 
    private void PopulateLists()
    {
        employees.Add(new Employee("Harry"));
        employees.Add(new Employee("Sally"));
        employees.Add(new Employee("Roy"));
        employees.Add(new Employee("Pris"));
        tasks.Add(new Task(1, employees[1]));
        tasks.Add(new Task(2));
        tasks.Add(new Task(3, employees[2]));
        tasks.Add(new Task(4));
    }

    // Configures columns for the DataGridView control.
    private void AddColumns()
    {
        DataGridViewTextBoxColumn idColumn = 
            new DataGridViewTextBoxColumn();
        idColumn.Name = "Task";
        idColumn.DataPropertyName = "Id";
        idColumn.ReadOnly = true;

        DataGridViewComboBoxColumn assignedToColumn = 
            new DataGridViewComboBoxColumn();

        // Populate the combo box drop-down list with Employee objects. 
        foreach (Employee e in employees) assignedToColumn.Items.Add(e);

        // Add "unassigned" to the drop-down list and display it for 
        // empty AssignedTo values or when the user presses CTRL+0. 
        assignedToColumn.Items.Add("unassigned");
        assignedToColumn.DefaultCellStyle.NullValue = "unassigned";

        assignedToColumn.Name = "Assigned To";
        assignedToColumn.DataPropertyName = "AssignedTo";
        assignedToColumn.AutoComplete = true;
        assignedToColumn.DisplayMember = "Name";
        assignedToColumn.ValueMember = "Self";

        // Add a button column. 
        DataGridViewButtonColumn buttonColumn = 
            new DataGridViewButtonColumn();
        buttonColumn.HeaderText = "";
        buttonColumn.Name = "Status Request";
        buttonColumn.Text = "Request Status";
        buttonColumn.UseColumnTextForButtonValue = true;

        dataGridView1.Columns.Add(idColumn);
        dataGridView1.Columns.Add(assignedToColumn);
        dataGridView1.Columns.Add(buttonColumn);

        // Add a CellClick handler to handle clicks in the button column.
        dataGridView1.CellClick +=
            new DataGridViewCellEventHandler(dataGridView1_CellClick);
    }

    // Reports on task assignments. 
    private void reportButton_Click(object sender, EventArgs e)
    {
        StringBuilder report = new StringBuilder();
        foreach (Task t in tasks)
        {
            String assignment = 
                t.AssignedTo == null ? 
                "unassigned" : "assigned to " + t.AssignedTo.Name;
            report.AppendFormat("Task {0} is {1}.", t.Id, assignment);
            report.Append(Environment.NewLine);
        }
        MessageBox.Show(report.ToString(), "Task Assignments");
    }

    // Calls the Employee.RequestStatus method.
    void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
    {
        // Ignore clicks that are not on button cells. 
        if (e.RowIndex < 0 || e.ColumnIndex !=
            dataGridView1.Columns["Status Request"].Index) return;

        // Retrieve the task ID.
        Int32 taskID = (Int32)dataGridView1[0, e.RowIndex].Value;

        // Retrieve the Employee object from the "Assigned To" cell.
        Employee assignedTo = dataGridView1.Rows[e.RowIndex]
            .Cells["Assigned To"].Value as Employee;

        // Request status through the Employee object if present. 
        if (assignedTo != null)
        {
            assignedTo.RequestStatus(taskID);
        }
        else
        {
            MessageBox.Show(String.Format(
                "Task {0} is unassigned.", taskID), "Status Request");
        }
    }
}

Public Class Form1
    Inherits Form

    Private employees As New List(Of Employee)
    Private tasks As New List(Of Task)
    Private WithEvents reportButton As New Button
    Private WithEvents dataGridView1 As New DataGridView

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

    Sub New()
        dataGridView1.Dock = DockStyle.Fill
        dataGridView1.AutoSizeColumnsMode = _
            DataGridViewAutoSizeColumnsMode.AllCells
        reportButton.Text = "Generate Report"
        reportButton.Dock = DockStyle.Top

        Controls.Add(dataGridView1)
        Controls.Add(reportButton)
        Text = "DataGridViewComboBoxColumn Demo"
    End Sub

    ' Initializes the data source and populates the DataGridView control.
    Private Sub Form1_Load(ByVal sender As Object, _
        ByVal e As EventArgs) Handles Me.Load

        PopulateLists()
        dataGridView1.AutoGenerateColumns = False
        dataGridView1.DataSource = tasks
        AddColumns()

    End Sub

    ' Populates the employees and tasks lists. 
    Private Sub PopulateLists()
        employees.Add(New Employee("Harry"))
        employees.Add(New Employee("Sally"))
        employees.Add(New Employee("Roy"))
        employees.Add(New Employee("Pris"))
        tasks.Add(New Task(1, employees(1)))
        tasks.Add(New Task(2))
        tasks.Add(New Task(3, employees(2)))
        tasks.Add(New Task(4))
    End Sub

    ' Configures columns for the DataGridView control.
    Private Sub AddColumns()

        Dim idColumn As New DataGridViewTextBoxColumn()
        idColumn.Name = "Task"
        idColumn.DataPropertyName = "Id"
        idColumn.ReadOnly = True

        Dim assignedToColumn As New DataGridViewComboBoxColumn()

        ' Populate the combo box drop-down list with Employee objects. 
        For Each e As Employee In employees
            assignedToColumn.Items.Add(e)
        Next

        ' Add "unassigned" to the drop-down list and display it for 
        ' empty AssignedTo values or when the user presses CTRL+0. 
        assignedToColumn.Items.Add("unassigned")
        assignedToColumn.DefaultCellStyle.NullValue = "unassigned"

        assignedToColumn.Name = "Assigned To"
        assignedToColumn.DataPropertyName = "AssignedTo"
        assignedToColumn.AutoComplete = True
        assignedToColumn.DisplayMember = "Name"
        assignedToColumn.ValueMember = "Self"

        ' Add a button column. 
        Dim buttonColumn As New DataGridViewButtonColumn()
        buttonColumn.HeaderText = ""
        buttonColumn.Name = "Status Request"
        buttonColumn.Text = "Request Status"
        buttonColumn.UseColumnTextForButtonValue = True

        dataGridView1.Columns.Add(idColumn)
        dataGridView1.Columns.Add(assignedToColumn)
        dataGridView1.Columns.Add(buttonColumn)

    End Sub

    ' Reports on task assignments. 
    Private Sub reportButton_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles reportButton.Click

        Dim report As New StringBuilder()
        For Each t As Task In tasks
            Dim assignment As String
            If t.AssignedTo Is Nothing Then
                assignment = "unassigned"
            Else
                assignment = "assigned to " + t.AssignedTo.Name
            End If
            report.AppendFormat("Task {0} is {1}.", t.Id, assignment)
            report.Append(Environment.NewLine)
        Next
        MessageBox.Show(report.ToString(), "Task Assignments")

    End Sub

    ' Calls the Employee.RequestStatus method.
    Private Sub dataGridView1_CellClick(ByVal sender As Object, _
        ByVal e As DataGridViewCellEventArgs) _
        Handles dataGridView1.CellClick

        ' Ignore clicks that are not on button cells. 
        If e.RowIndex < 0 OrElse Not e.ColumnIndex = _
            dataGridView1.Columns("Status Request").Index Then Return

        ' Retrieve the task ID.
        Dim taskID As Int32 = CInt(dataGridView1(0, e.RowIndex).Value)

        ' Retrieve the Employee object from the "Assigned To" cell.
        Dim assignedTo As Employee = TryCast(dataGridView1.Rows(e.RowIndex) _
            .Cells("Assigned To").Value, Employee)

        ' Request status through the Employee object if present. 
        If assignedTo IsNot Nothing Then
            assignedTo.RequestStatus(taskID)
        Else
            MessageBox.Show(String.Format( _
                "Task {0} is unassigned.", taskID), "Status Request")
        End If

    End Sub

End Class

Kommentarer

Klassen DataGridViewButtonColumn är en specialiserad typ av klassen DataGridViewColumn som används för att logiskt vara värd för celler som svarar på enkla användarindata. A DataGridViewButtonColumn har en associerad DataGridViewButtonCell i varje DataGridViewRow som korsar den. Varje cell tillhandahåller ett användargränssnitt (UI) som liknar en Button kontroll.

Om du vill visa samma knapptext för varje cell anger du UseColumnTextForButtonValue egenskapen till true och anger Text egenskapen till önskad knapptext.

Standardsorteringsläget för den här kolumntypen är NotSortable.

Om du vill svara på klick på användarknappar hanterar du DataGridView.CellClick händelsen eller DataGridView.CellContentClick . I händelsehanteraren kan du använda DataGridViewCellEventArgs.ColumnIndex egenskapen för att avgöra om klicket inträffade i knappkolumnen. Du kan använda DataGridViewCellEventArgs.RowIndex egenskapen för att avgöra om klicket inträffade i en knappcell och inte i kolumnrubriken.

Anteckningar till arvingar

När du härleder från DataGridViewButtonColumn och lägger till nya egenskaper i den härledda klassen måste du åsidosätta Clone() metoden för att kopiera de nya egenskaperna under kloningsåtgärderna. Du bör också anropa basklassens Clone() metod så att egenskaperna för basklassen kopieras till den nya cellen.

Se även

• DataGridView
• DataGridViewColumn
• DataGridViewRow
• DataGridViewButtonCell
• Button
• SortMode
• CellClick
• Så här inaktiverar du knappar i en knappkolumn i Windows Forms DataGridView-kontrollen