LEADTOOLS Windows Forms (Leadtools.WinForms assembly)
LEAD Technologies, Inc

RasterImageList Class

Example 





Members 
Represents an image list control, which displays a collection of items that can be displayed using one of the RasterImageListViewStyle styles.
Object Model
RasterImageList ClassRasterImageListItemCollection ClassRasterImageListItem ClassRasterImageListItemCollection ClassRasterImageListItem Class
Syntax
[DesignerAttribute(DesignerBaseTypeName="System.ComponentModel.Design.IDesigner", DesignerTypeName="Leadtools.WinForms.RasterImageListDesigner, Leadtools.WinForms, Version=17.5.0.0, Culture=neutral, PublicKeyToken=null")]
[DefaultPropertyAttribute("ViewStyle")]
[DefaultEventAttribute("SelectedIndexChanged")]
[ToolboxBitmapAttribute()]
public class RasterImageList : System.Windows.Forms.Control, System.ComponentModel.IComponentSystem.ComponentModel.ISynchronizeInvokeSystem.IDisposableSystem.Windows.Forms.IBindableComponentSystem.Windows.Forms.IDropTargetSystem.Windows.Forms.IWin32Window  
'Declaration
 
<DesignerAttribute(DesignerBaseTypeName="System.ComponentModel.Design.IDesigner", DesignerTypeName="Leadtools.WinForms.RasterImageListDesigner, Leadtools.WinForms, Version=17.5.0.0, Culture=neutral, PublicKeyToken=null")>
<DefaultPropertyAttribute("ViewStyle")>
<DefaultEventAttribute("SelectedIndexChanged")>
<ToolboxBitmapAttribute()>
Public Class RasterImageList 
   Inherits System.Windows.Forms.Control
   Implements System.ComponentModel.IComponentSystem.ComponentModel.ISynchronizeInvokeSystem.IDisposableSystem.Windows.Forms.IBindableComponentSystem.Windows.Forms.IDropTargetSystem.Windows.Forms.IWin32Window 
'Usage
 
Dim instance As RasterImageList
function Leadtools.WinForms.RasterImageList()
[DesignerAttribute(DesignerBaseTypeName="System.ComponentModel.Design.IDesigner", DesignerTypeName="Leadtools.WinForms.RasterImageListDesigner, Leadtools.WinForms, Version=17.5.0.0, Culture=neutral, PublicKeyToken=null")]
[DefaultPropertyAttribute("ViewStyle")]
[DefaultEventAttribute("SelectedIndexChanged")]
[ToolboxBitmapAttribute()]
public ref class RasterImageList : public System.Windows.Forms.Control, System.ComponentModel.IComponentSystem.ComponentModel.ISynchronizeInvokeSystem.IDisposableSystem.Windows.Forms.IBindableComponentSystem.Windows.Forms.IDropTargetSystem.Windows.Forms.IWin32Window  
Remarks

The RasterImageList control lets you display and manipulate a list of images. The RasterImageList control contains a list of items that can be used to view thumbnails of Leadtools.RasterImage objects.

A RasterImageList control allows you to display a list of items with text and an Leadtools.RasterImage. For example, the Windows Explorer in Thumbnails mode is similar in appearance to a RasterImageList control. The RasterImageListItem class represents an item within a RasterImageList control. The items that are displayed in the list can be shown using one of the RasterImageListViewStyle styles.
RasterImageList supports single or multiple item selection. The multiple selection feature lets the user select from a list of items in a way similar to a System.Windows.Forms.ListBox control. Additionally, the user can activate selected items to perform a task. For example, you could use a RasterImageList control to display a list of files that the application can then open and utilize. The user can select the files to open and then double-click them to activate the items and open the files in the application.

RasterImageList provides a large number of properties that provide flexibility in appearance and behavior. The ViewStyle property allows you to change the way in which items are displayed. Items are added and removed from the RasterImageList through the Items property. The Items property allows you to access the RasterImageListItemCollection of the control, which provides methods for manipulating the items in the control. When your control contains a large number of items, it is often easier for the user to see them in a sorted list. You can use the Sorting property to sort the items alphabetically.

In addition to the many properties that are available for a RasterImageList control, there are methods and events that your application can use to provide additional capabilities to the RasterImageList. The BeginUpdate and EndUpdate methods allow you to add many items to a RasterImageList without displaying the repainting of the control each time an item is added, thus improving performance. You you may want to provide functionality when the user right-clicks an item. To determine the item which is being clicked, you can use the HitTest method or you can manually calculate what item is displayed in what position using the GetItemRectangle method. Sometimes you want to display a specific item to the user to view. The EnsureVisible method can be called to ensure that the specific item is in the visible area of the control.

When the user changes the selected items with the keyboard or mouse, the control will fire the SelectedIndexChanged event. You can then read the SelectedItems to get a list of the currently selected items.


NOTE: For automatic generation of thumbnails from files stored on your computer, see RasterThumbnailBrowser.
Example
 
Private Class MyForm1 : Inherits Form
      Public imageList As RasterImageList
      Public Sub New(ByVal title As String)
         Text = title
         ' Set the size of the form
         Size = New Size(400, 200)

         ' Create a new RasterImageList control.
         imageList = New RasterImageList()
         imageList.Bounds = New Rectangle(New Point(0, 0), Size)

         imageList.Sorting = SortOrder.Ascending
         imageList.BorderStyle = BorderStyle.None
         imageList.DoubleBuffer = True
         imageList.Dock = DockStyle.Fill
         Dim paintProperties As RasterPaintProperties = imageList.PaintProperties
         paintProperties.PaintDisplayMode = RasterPaintDisplayModeFlags.Bicubic
         imageList.PaintProperties = paintProperties
         imageList.EnableKeyboard = True
         imageList.UseDpi = True


         ' Add a handler to the PaintBackground event
         AddHandler imageList.PaintBackground, AddressOf rasterImageList_PaintBackground

         Dim codecs As RasterCodecs = New RasterCodecs()

         ' Create three items
         Dim imagesPath As String = LEAD_VARS.ImagesDir

         For i As Integer = 0 To 2
            ' Load the image
            Dim index As Integer = i + 1
            Dim imageFileName As String = Path.Combine(imagesPath, "ImageProcessingDemo\Image" & index.ToString() & ".cmp")
            Dim image As RasterImage = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)
            Dim item As RasterImageListItem = New RasterImageListItem(image, 1, "Item" & index.ToString())

            ' Select the first item
            If i = 0 Then
               item.Selected = True
            End If

            ' Add the item to the image list
            imageList.Items.Add(item)
         Next i

         ' Add the RasterImageList to the control collection.
         Controls.Add(imageList)
      End Sub


      Private Sub rasterImageList_PaintBackground(ByVal sender As Object, ByVal e As PaintEventArgs)
         ' Get the image list control
         Dim imageList As RasterImageList = CType(IIf(TypeOf sender Is RasterImageList, sender, Nothing), RasterImageList)

         ' Fill the background with a gradient brush
         Dim rc As Rectangle = imageList.ClientRectangle

         Dim b As Brush = New LinearGradientBrush(rc, Color.Bisque, Color.White, LinearGradientMode.Vertical)
         e.Graphics.FillRectangle(b, rc)
         b.Dispose()
      End Sub

   End Class

   Public Sub RasterImageList_RasterImageList(ByVal title As String)
      Dim form As MyForm1 = New MyForm1(title)
      form.ShowDialog()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
class MyForm1 : Form
   {
      public RasterImageList imageList;
      public MyForm1(string title)
      {
         Text = title;
         // Set the size of the form
         Size = new Size(400, 200);

         // Create a new RasterImageList control.
         imageList = new RasterImageList();
         imageList.Bounds = new Rectangle(new Point(0, 0), Size);

         imageList.Sorting = SortOrder.Ascending;
         imageList.BorderStyle = BorderStyle.None;
         imageList.DoubleBuffer = true;
         imageList.Dock = DockStyle.Fill;
         RasterPaintProperties paintProperties = imageList.PaintProperties;
         paintProperties.PaintDisplayMode = RasterPaintDisplayModeFlags.Bicubic;
         imageList.PaintProperties = paintProperties;
         imageList.EnableKeyboard = true;
         imageList.UseDpi = true;

         // Add a handler to the PaintBackground event
         imageList.PaintBackground += new PaintEventHandler(rasterImageList_PaintBackground);

         RasterCodecs codecs = new RasterCodecs();

         // Create three items
         string imagesPath = LEAD_VARS.ImagesDir;

         for(int i = 0; i < 3; i++)
         {
            // Load the image
            int index = i + 1;
            string imageFileName = Path.Combine(imagesPath, @"ImageProcessingDemo\Image" + index.ToString() + ".cmp");
            RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1);
            RasterImageListItem item = new RasterImageListItem(image, 1, "Item" + index.ToString());

            // Select the first item
            if(i == 0)
               item.Selected = true;

            // Add the item to the image list
            imageList.Items.Add(item);
         }

         // Add the RasterImageList to the control collection.
         Controls.Add(imageList);
      }


      private void rasterImageList_PaintBackground(object sender, PaintEventArgs e)
      {
         // Get the image list control
         RasterImageList imageList = sender as RasterImageList;

         // Fill the background with a gradient brush
         Rectangle rc = imageList.ClientRectangle;

         Brush b = new LinearGradientBrush(
            rc,
            Color.Bisque,
            Color.White,
            LinearGradientMode.Vertical);
         e.Graphics.FillRectangle(b, rc);
         b.Dispose();
      }

   }

   public void RasterImageList_RasterImageList(string title)
   {
      MyForm1 form = new MyForm1(title);
      form.ShowDialog();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also

Reference

RasterImageList Members
Leadtools.WinForms Namespace

 

 


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