DrawListViewColumnHeaderEventArgs DrawListViewColumnHeaderEventArgs DrawListViewColumnHeaderEventArgs DrawListViewColumnHeaderEventArgs Class

Определение

Предоставляет данные для события DrawColumnHeader.Provides data for the DrawColumnHeader event.

public ref class DrawListViewColumnHeaderEventArgs : EventArgs
public class DrawListViewColumnHeaderEventArgs : EventArgs
type DrawListViewColumnHeaderEventArgs = class
    inherit EventArgs
Public Class DrawListViewColumnHeaderEventArgs
Inherits EventArgs
Наследование
DrawListViewColumnHeaderEventArgsDrawListViewColumnHeaderEventArgsDrawListViewColumnHeaderEventArgsDrawListViewColumnHeaderEventArgs

Примеры

В следующем примере кода показано, как реализовать пользовательское рисование для ListView элемента управления.The following code example demonstrates how to provide custom drawing for a ListView control. ListView Элемент управления в примере имеет градиентным фоном.The ListView control in the example has a gradient background. Подэлементов с отрицательными значениями у красным цветом текста и черном фоне.Subitems with negative values have a red foreground and a black background.

Обработчик для ListView.DrawItem события рисует фон для всех элементов.A handler for the ListView.DrawItem event draws the background for entire items. Обработчик для ListView.DrawSubItem события рисует текстовых значений и текста и фона для подэлементов, содержащих отрицательные значения.A handler for the ListView.DrawSubItem event draws the text values and both the text and background for subitems that have negative values. Обработчик для DrawColumnHeader события рисует Заголовок каждого столбца.A handler for the DrawColumnHeader event draws each column header.

Объект ContextMenu компонент позволяет переключаться между в представлении сведений и в представлении списка.A ContextMenu component provides a way to switch between the details view and the list view. В представлении списка, только ListView.DrawItem события.In the list view, only the ListView.DrawItem event is fired. В этом случае текста и фона и отображаются в ListView.DrawItem обработчик событий.In this case, the text and background are both drawn in the ListView.DrawItem event handler.

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Globalization;
using System.Windows.Forms;

public class ListViewOwnerDraw : Form
{
    private ListView listView1 = new ListView();
    private ContextMenu contextMenu1 = new ContextMenu();

    public ListViewOwnerDraw()
    {
        // Initialize the ListView control.
        listView1.BackColor = Color.Black;
        listView1.ForeColor = Color.White;
        listView1.Dock = DockStyle.Fill;
        listView1.View = View.Details;
        listView1.FullRowSelect = true;

        // Add columns to the ListView control.
        listView1.Columns.Add("Name", 100, HorizontalAlignment.Center);
        listView1.Columns.Add("First", 100, HorizontalAlignment.Center);
        listView1.Columns.Add("Second", 100, HorizontalAlignment.Center);
        listView1.Columns.Add("Third", 100, HorizontalAlignment.Center);

        // Create items and add them to the ListView control.
        ListViewItem listViewItem1 = new ListViewItem(new string[] { "One", "20", "30", "-40" }, -1);
        ListViewItem listViewItem2 = new ListViewItem(new string[] { "Two", "-250", "145", "37" }, -1);
        ListViewItem listViewItem3 = new ListViewItem(new string[] { "Three", "200", "800", "-1,001" }, -1);
        ListViewItem listViewItem4 = new ListViewItem(new string[] { "Four", "not available", "-2", "100" }, -1);
        listView1.Items.AddRange(new ListViewItem[] { listViewItem1, listViewItem2, listViewItem3, listViewItem4 });

        // Initialize the shortcut menu and 
        // assign it to the ListView control.
        contextMenu1.MenuItems.Add("List",
            new EventHandler(menuItemList_Click));
        contextMenu1.MenuItems.Add("Details",
            new EventHandler(menuItemDetails_Click));
        listView1.ContextMenu = contextMenu1;

        // Configure the ListView control for owner-draw and add 
        // handlers for the owner-draw events.
        listView1.OwnerDraw = true;
        listView1.DrawItem += new
            DrawListViewItemEventHandler(listView1_DrawItem);
        listView1.DrawSubItem += new
            DrawListViewSubItemEventHandler(listView1_DrawSubItem);
        listView1.DrawColumnHeader += new
            DrawListViewColumnHeaderEventHandler(listView1_DrawColumnHeader);

        // Add a handler for the MouseUp event so an item can be 
        // selected by clicking anywhere along its width.
        listView1.MouseUp += new MouseEventHandler(listView1_MouseUp);

        // Add handlers for various events to compensate for an 
        // extra DrawItem event that occurs the first time the mouse 
        // moves over each row. 
        listView1.MouseMove += new MouseEventHandler(listView1_MouseMove);
        listView1.ColumnWidthChanged += new ColumnWidthChangedEventHandler(listView1_ColumnWidthChanged);
        listView1.Invalidated += new InvalidateEventHandler(listView1_Invalidated);

        // Initialize the form and add the ListView control to it.
        this.ClientSize = new Size(450, 150);
        this.FormBorderStyle = FormBorderStyle.FixedSingle;
        this.MaximizeBox = false;
        this.Text = "ListView OwnerDraw Example";
        this.Controls.Add(listView1);
    }

    // Clean up any resources being used.        
    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            contextMenu1.Dispose();
        }
        base.Dispose(disposing);
    }

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

    // Sets the ListView control to the List view.
    private void menuItemList_Click(object sender, EventArgs e)
    {
        listView1.View = View.List;
        listView1.Invalidate();
    }

    // Sets the ListView control to the Details view.
    private void menuItemDetails_Click(object sender, EventArgs e)
    {
        listView1.View = View.Details;

        // Reset the tag on each item to re-enable the workaround in
        // the MouseMove event handler.
        foreach (ListViewItem item in listView1.Items)
        {
            item.Tag = null;
        }
    }

    // Selects and focuses an item when it is clicked anywhere along 
    // its width. The click must normally be on the parent item text.
    private void listView1_MouseUp(object sender, MouseEventArgs e)
    {
        ListViewItem clickedItem = listView1.GetItemAt(5, e.Y);
        if (clickedItem != null)
        {
            clickedItem.Selected = true;
            clickedItem.Focused = true;
        }
    }

    // Draws the backgrounds for entire ListView items.
    private void listView1_DrawItem(object sender,
        DrawListViewItemEventArgs e)
    {
        if ((e.State & ListViewItemStates.Selected) != 0)
        {
            // Draw the background and focus rectangle for a selected item.
            e.Graphics.FillRectangle(Brushes.Maroon, e.Bounds);
            e.DrawFocusRectangle();
        }
        else
        {
            // Draw the background for an unselected item.
            using (LinearGradientBrush brush =
                new LinearGradientBrush(e.Bounds, Color.Orange,
                Color.Maroon, LinearGradientMode.Horizontal))
            {
                e.Graphics.FillRectangle(brush, e.Bounds);
            }
        }

        // Draw the item text for views other than the Details view.
        if (listView1.View != View.Details)
        {
            e.DrawText();
        }
    }

    // Draws subitem text and applies content-based formatting.
    private void listView1_DrawSubItem(object sender,
        DrawListViewSubItemEventArgs e)
    {
        TextFormatFlags flags = TextFormatFlags.Left;

        using (StringFormat sf = new StringFormat())
        {
            // Store the column text alignment, letting it default
            // to Left if it has not been set to Center or Right.
            switch (e.Header.TextAlign)
            {
                case HorizontalAlignment.Center:
                    sf.Alignment = StringAlignment.Center;
                    flags = TextFormatFlags.HorizontalCenter;
                    break;
                case HorizontalAlignment.Right:
                    sf.Alignment = StringAlignment.Far;
                    flags = TextFormatFlags.Right;
                    break;
            }

            // Draw the text and background for a subitem with a 
            // negative value. 
            double subItemValue;
            if (e.ColumnIndex > 0 && Double.TryParse(
                e.SubItem.Text, NumberStyles.Currency,
                NumberFormatInfo.CurrentInfo, out subItemValue) &&
                subItemValue < 0)
            {
                // Unless the item is selected, draw the standard 
                // background to make it stand out from the gradient.
                if ((e.ItemState & ListViewItemStates.Selected) == 0)
                {
                    e.DrawBackground();
                }

                // Draw the subitem text in red to highlight it. 
                e.Graphics.DrawString(e.SubItem.Text,
                    listView1.Font, Brushes.Red, e.Bounds, sf);

                return;
            }

            // Draw normal text for a subitem with a nonnegative 
            // or nonnumerical value.
            e.DrawText(flags);
        }
    }

    // Draws column headers.
    private void listView1_DrawColumnHeader(object sender,
        DrawListViewColumnHeaderEventArgs e)
    {
        using (StringFormat sf = new StringFormat())
        {
            // Store the column text alignment, letting it default
            // to Left if it has not been set to Center or Right.
            switch (e.Header.TextAlign)
            {
                case HorizontalAlignment.Center:
                    sf.Alignment = StringAlignment.Center;
                    break;
                case HorizontalAlignment.Right:
                    sf.Alignment = StringAlignment.Far;
                    break;
            }

            // Draw the standard header background.
            e.DrawBackground();

            // Draw the header text.
            using (Font headerFont =
                        new Font("Helvetica", 10, FontStyle.Bold))
            {
                e.Graphics.DrawString(e.Header.Text, headerFont,
                    Brushes.Black, e.Bounds, sf);
            }
        }
        return;
    }

    // Forces each row to repaint itself the first time the mouse moves over 
    // it, compensating for an extra DrawItem event sent by the wrapped 
    // Win32 control. This issue occurs each time the ListView is invalidated.
    private void listView1_MouseMove(object sender, MouseEventArgs e)
    {
        ListViewItem item = listView1.GetItemAt(e.X, e.Y);
        if (item != null && item.Tag == null)
        {
            listView1.Invalidate(item.Bounds);
            item.Tag = "tagged";
        }
    }

    // Resets the item tags. 
    void listView1_Invalidated(object sender, InvalidateEventArgs e)
    {
        foreach (ListViewItem item in listView1.Items)
        {
            if (item == null) return;
            item.Tag = null;
        }
    }

    // Forces the entire control to repaint if a column width is changed.
    void listView1_ColumnWidthChanged(object sender, 
        ColumnWidthChangedEventArgs e)
    {
        listView1.Invalidate();
    }

}
Imports System
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Globalization
Imports System.Windows.Forms

Public Class ListViewOwnerDraw
    Inherits Form
    Private WithEvents listView1 As New ListView()
    Private WithEvents contextMenu1 As New ContextMenu()
    Private WithEvents listMenuItem As New MenuItem("List")
    Private WithEvents detailsMenuItem As New MenuItem("Details")

    Public Sub New()

        ' Initialize the shortcut menu. 
        contextMenu1.MenuItems.AddRange(New MenuItem() _
            {Me.listMenuItem, Me.detailsMenuItem})

        ' Initialize the ListView control.
        With Me.listView1
            .BackColor = Color.Black
            .ForeColor = Color.White
            .Dock = DockStyle.Fill
            .View = View.Details
            .FullRowSelect = True
            .OwnerDraw = True
            .ContextMenu = Me.contextMenu1
        End With

        ' Add columns to the ListView control.
        With Me.listView1.Columns
            .Add("Name", 100, HorizontalAlignment.Center)
            .Add("First", 100, HorizontalAlignment.Center)
            .Add("Second", 100, HorizontalAlignment.Center)
            .Add("Third", 100, HorizontalAlignment.Center)
        End With

        ' Create items and add them to the ListView control.
        Dim listViewItem1 As New ListViewItem(New String() _
            {"One", "20", "30", "-40"}, -1)
        Dim listViewItem2 As New ListViewItem(New String() _
            {"Two", "-250", "145", "37"}, -1)
        Dim listViewItem3 As New ListViewItem(New String() _
            {"Three", "200", "800", "-1,001"}, -1)
        Dim listViewItem4 As New ListViewItem(New String() _
            {"Four", "not available", "-2", "100"}, -1)
        Me.listView1.Items.AddRange(New ListViewItem() _
            {listViewItem1, listViewItem2, listViewItem3, listViewItem4})

        ' Initialize the form and add the ListView control to it.
        With Me
            .ClientSize = New Size(450, 150)
            .FormBorderStyle = FormBorderStyle.FixedSingle
            .MaximizeBox = False
            .Text = "ListView OwnerDraw Example"
            .Controls.Add(Me.listView1)
        End With

    End Sub

    ' Clean up any resources being used.        
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            contextMenu1.Dispose()
        End If
        MyBase.Dispose(disposing)
    End Sub

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

    ' Sets the ListView control to the List view.
    Private Sub menuItemList_Click(ByVal sender As Object, _
        ByVal e As EventArgs) _
        Handles listMenuItem.Click

        Me.listView1.View = View.List

    End Sub

    ' Sets the ListView control to the Details view.
    Private Sub menuItemDetails_Click(ByVal sender As Object, _
        ByVal e As EventArgs) _
        Handles detailsMenuItem.Click

        Me.listView1.View = View.Details

        ' Reset the tag on each item to re-enable the workaround 
        ' in the MouseMove event handler.
        For Each item As ListViewItem In listView1.Items
            item.Tag = Nothing
        Next

    End Sub

    ' Selects and focuses an item when it is clicked anywhere along 
    ' its width. The click must normally be on the parent item text.
    Private Sub listView1_MouseUp(ByVal sender As Object, _
        ByVal e As MouseEventArgs) _
        Handles listView1.MouseUp

        Dim clickedItem As ListViewItem = Me.listView1.GetItemAt(5, e.Y)
        If (clickedItem IsNot Nothing) Then
            clickedItem.Selected = True
            clickedItem.Focused = True
        End If

    End Sub

    ' Draws the backgrounds for entire ListView items.
    Private Sub listView1_DrawItem(ByVal sender As Object, _
        ByVal e As DrawListViewItemEventArgs) _
        Handles listView1.DrawItem

        If Not (e.State And ListViewItemStates.Selected) = 0 Then

            ' Draw the background for a selected item.
            e.Graphics.FillRectangle(Brushes.Maroon, e.Bounds)
            e.DrawFocusRectangle()

        Else

            ' Draw the background for an unselected item.
            Dim brush As New LinearGradientBrush(e.Bounds, Color.Orange, _
                Color.Maroon, LinearGradientMode.Horizontal)
            Try
                e.Graphics.FillRectangle(brush, e.Bounds)
            Finally
                brush.Dispose()
            End Try

        End If

        ' Draw the item text for views other than the Details view.
        If Not Me.listView1.View = View.Details Then
            e.DrawText()
        End If

    End Sub

    ' Draws subitem text and applies content-based formatting.
    Private Sub listView1_DrawSubItem(ByVal sender As Object, _
        ByVal e As DrawListViewSubItemEventArgs) _
        Handles listView1.DrawSubItem

        Dim flags As TextFormatFlags = TextFormatFlags.Left

        Dim sf As New StringFormat()
        Try

            ' Store the column text alignment, letting it default
            ' to Left if it has not been set to Center or Right.
            Select Case e.Header.TextAlign
                Case HorizontalAlignment.Center
                    sf.Alignment = StringAlignment.Center
                    flags = TextFormatFlags.HorizontalCenter
                Case HorizontalAlignment.Right
                    sf.Alignment = StringAlignment.Far
                    flags = TextFormatFlags.Right
            End Select

            ' Draw the text and background for a subitem with a 
            ' negative value. 
            Dim subItemValue As Double
            If e.ColumnIndex > 0 AndAlso _
                Double.TryParse(e.SubItem.Text, NumberStyles.Currency, _
                NumberFormatInfo.CurrentInfo, subItemValue) AndAlso _
                subItemValue < 0 Then

                ' Unless the item is selected, draw the standard 
                ' background to make it stand out from the gradient.
                If (e.ItemState And ListViewItemStates.Selected) = 0 Then
                    e.DrawBackground()
                End If

                ' Draw the subitem text in red to highlight it. 
                e.Graphics.DrawString(e.SubItem.Text, _
                    Me.listView1.Font, Brushes.Red, e.Bounds, sf)

                Return

            End If

            ' Draw normal text for a subitem with a nonnegative 
            ' or nonnumerical value.
            e.DrawText(flags)

        Finally
            sf.Dispose()
        End Try

    End Sub

    ' Draws column headers.
    Private Sub listView1_DrawColumnHeader(ByVal sender As Object, _
        ByVal e As DrawListViewColumnHeaderEventArgs) _
        Handles listView1.DrawColumnHeader

        Dim sf As New StringFormat()
        Try

            ' Store the column text alignment, letting it default
            ' to Left if it has not been set to Center or Right.
            Select Case e.Header.TextAlign
                Case HorizontalAlignment.Center
                    sf.Alignment = StringAlignment.Center
                Case HorizontalAlignment.Right
                    sf.Alignment = StringAlignment.Far
            End Select

            ' Draw the standard header background.
            e.DrawBackground()

            ' Draw the header text.
            Dim headerFont As New Font("Helvetica", 10, FontStyle.Bold)
            Try
                e.Graphics.DrawString(e.Header.Text, headerFont, _
                    Brushes.Black, e.Bounds, sf)
            Finally
                headerFont.Dispose()
            End Try

        Finally
            sf.Dispose()
        End Try

    End Sub

    ' Forces each row to repaint itself the first time the mouse moves over 
    ' it, compensating for an extra DrawItem event sent by the wrapped 
    ' Win32 control.
    Private Sub listView1_MouseMove(ByVal sender As Object, _
        ByVal e As MouseEventArgs) _
        Handles listView1.MouseMove

        Dim item As ListViewItem = listView1.GetItemAt(e.X, e.Y)
        If item IsNot Nothing AndAlso item.Tag Is Nothing Then
            listView1.Invalidate(item.Bounds)
            item.Tag = "tagged"
        End If

    End Sub

    ' Resets the item tags. 
    Private Sub listView1_Invalidated(ByVal sender As Object, _
        ByVal e As InvalidateEventArgs) Handles listView1.Invalidated

        For Each item As ListViewItem In listView1.Items
            If item Is Nothing Then Return
            item.Tag = Nothing
        Next

    End Sub

    ' Forces the entire control to repaint if a column width is changed.
    Private Sub listView1_ColumnWidthChanged(ByVal sender As Object, _
        ByVal e As ColumnWidthChangedEventArgs) Handles listView1.ColumnWidthChanged

        listView1.Invalidate()

    End Sub

End Class

Комментарии

ListView.DrawColumnHeader Событие позволяет настроить (или пользовательской отрисовки) внешний вид ListView элемента управления в представлении сведений.The ListView.DrawColumnHeader event lets you customize (or owner-draw) the appearance of a ListView control in the details view.

ListView.DrawColumnHeader Событие ListView управления его ListView.OwnerDraw свойству true и его View свойству Details.The ListView.DrawColumnHeader event is raised by a ListView control when its ListView.OwnerDraw property is set to true and its View property is set to Details. DrawListViewColumnHeaderEventArgs Передать обработчик для события содержит сведения о ColumnHeader для рисования и также предоставляет методы для рисования заголовка.The DrawListViewColumnHeaderEventArgs passed to the event handler contains information about the ColumnHeader to draw and also provides methods to help you draw the header.

Используйте Header свойство для получения сведений о заголовке столбца для рисования.Use the Header property to retrieve information about the column header to draw. Используйте Graphics свойство для фактического рисования в пределах области, заданной Bounds свойство.Use the Graphics property to do the actual drawing within the area specified by the Bounds property. Для рисования standard ListView элементы, которые не требуют настройки, используют DrawBackground и DrawText методы.To draw standard ListView elements that do not need customization, use the DrawBackground and DrawText methods.

Используйте DrawDefault свойства, если требуется, чтобы операционная система для отрисовки подэлемента.Use the DrawDefault property when you want the operating system to draw the subitem. Это полезно в тех случаях, когда требуется настроить только определенные заголовки.This is useful when you want to customize only specific headers.

Примечание

Чтобы избежать проблем с графики мерцание при рисовании, владельцем прерывания ListView и задание DoubleBuffered свойства true.To avoid issues with graphics flickering when owner drawing, override the ListView control and set the DoubleBuffered property to true. Эта функция доступна только в Windows XP и семействе Windows Server 2003, когда приложение вызывает Application.EnableVisualStyles метод.This feature is available only on Windows XP and the Windows Server 2003 family when your application calls the Application.EnableVisualStyles method.

Конструкторы

DrawListViewColumnHeaderEventArgs(Graphics, Rectangle, Int32, ColumnHeader, ListViewItemStates, Color, Color, Font) DrawListViewColumnHeaderEventArgs(Graphics, Rectangle, Int32, ColumnHeader, ListViewItemStates, Color, Color, Font) DrawListViewColumnHeaderEventArgs(Graphics, Rectangle, Int32, ColumnHeader, ListViewItemStates, Color, Color, Font) DrawListViewColumnHeaderEventArgs(Graphics, Rectangle, Int32, ColumnHeader, ListViewItemStates, Color, Color, Font)

Инициализирует новый экземпляр класса DrawListViewColumnHeaderEventArgs.Initializes a new instance of the DrawListViewColumnHeaderEventArgs class.

Свойства

BackColor BackColor BackColor BackColor

Получает цвет фона заголовка.Gets the background color of the header.

Bounds Bounds Bounds Bounds

Получает размер и расположение рисуемого заголовка столбца.Gets the size and location of the column header to draw.

ColumnIndex ColumnIndex ColumnIndex ColumnIndex

Получает индекс объекта ColumnHeader, представляющего рисуемый заголовок.Gets the index of the ColumnHeader representing the header to draw.

DrawDefault DrawDefault DrawDefault DrawDefault

Получает или задает значение, указывающее, прорисовывается ли заголовок столбца операционной системой или владельцем.Gets or sets a value indicating whether the column header should be drawn by the operating system instead of owner-drawn.

Font Font Font Font

Получает шрифт, используемый для рисования текста заголовка столбца.Gets the font used to draw the column header text.

ForeColor ForeColor ForeColor ForeColor

Получает основной цвет заголовка.Gets the foreground color of the header.

Graphics Graphics Graphics Graphics

Получает объект Graphics, используемый для рисования заголовка столбца.Gets the Graphics used to draw the column header.

Header Header Header Header

Получает объект ColumnHeader, представляющий рисуемый заголовок столбца.Gets the ColumnHeader representing the column header to draw.

State State State State

Получает текущее состояние заголовка столбца.Gets the current state of the column header.

Методы

DrawBackground() DrawBackground() DrawBackground() DrawBackground()

Рисует фон заголовка столбца.Draws the background of the column header.

DrawText() DrawText() DrawText() DrawText()

Рисует текст заголовка столбца с использованием форматирования по умолчанию.Draws the column header text using the default formatting.

DrawText(TextFormatFlags) DrawText(TextFormatFlags) DrawText(TextFormatFlags) DrawText(TextFormatFlags)

Рисует текст заголовка столбца, форматируя его с использованием указанных значений TextFormatFlags.Draws the column header text, formatting it with the specified TextFormatFlags values.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Определяет, равен ли заданный объект текущему объекту.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Служит хэш-функцией по умолчанию.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Возвращает объект Type для текущего экземпляра.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Создает неполную копию текущего объекта Object.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Возвращает строку, представляющую текущий объект.Returns a string that represents the current object.

(Inherited from Object)

Применяется к

Дополнительно