Classe ImageList (System.Windows.Forms)

Cambia visualizzazione:
ScriptFree
Riferimento a .NET Framework
Classe ImageList

Fornisce i metodi per la gestione di un insieme di oggetti Image. La classe non può essere ereditata.

Spazio dei nomi: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

Sintassi

Visual Basic - (Dichiarazione)
Public NotInheritable Class ImageList
	Inherits Component
Visual Basic (Utilizzo)
Dim instance As ImageList

C#
public sealed class ImageList : Component
C++
public ref class ImageList sealed : public Component
J#
public final class ImageList extends Component
JScript
public final class ImageList extends Component
Note

ImageList viene utilizzato normalmente da altri controlli, come ListView, TreeView o ToolBar. È possibile aggiungere immagini bitmap o icone a ImageList; gli altri controlli possono utilizzare le immagini secondo le proprie esigenze.

ImageList utilizza un handle per gestire l'elenco delle immagini. La proprietà Handle non viene creata fino a quando determinate operazioni, tra cui il recupero di Count, di Handle e la chiamata di Draw, non sono eseguite sull'elenco immagini.

Esempio

Nell'esempio di codice riportato di seguito viene illustrato come selezionare, rimuovere e visualizzare le immagini.

Visual Basic
Imports System
Imports System.Drawing
Imports System.ComponentModel
Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private listBox1 As System.Windows.Forms.ListBox
    Private label3 As System.Windows.Forms.Label
    Private WithEvents button1 As System.Windows.Forms.Button
    Private WithEvents button2 As System.Windows.Forms.Button
    Private WithEvents button3 As System.Windows.Forms.Button
    Private WithEvents button4 As System.Windows.Forms.Button
    Private pictureBox1 As System.Windows.Forms.PictureBox
    Private imageList1 As System.Windows.Forms.ImageList
    Private openFileDialog1 As System.Windows.Forms.OpenFileDialog
    Protected myGraphics As Graphics
    Private panel1 As System.Windows.Forms.Panel
    Private label5 As System.Windows.Forms.Label
    Private currentImage As Integer = 0

    Public Sub New()
        imageList1 = New ImageList()

        InitializeComponent()
        ' The default image size is 16 x 16, which sets up a larger
        ' image size. 
        imageList1.ImageSize = New Size(255, 255)
        imageList1.TransparentColor = Color.White

        ' Assigns the graphics object to use in the draw options.
        myGraphics = Graphics.FromHwnd(panel1.Handle)

    End Sub 'New

    Private Sub InitializeComponent()

        Me.listBox1 = New System.Windows.Forms.ListBox()
        Me.label3 = New System.Windows.Forms.Label()
        Me.button1 = New System.Windows.Forms.Button()
        Me.button2 = New System.Windows.Forms.Button()
        Me.button3 = New System.Windows.Forms.Button()
        Me.button4 = New System.Windows.Forms.Button()
        Me.pictureBox1 = New System.Windows.Forms.PictureBox()
        Me.openFileDialog1 = New System.Windows.Forms.OpenFileDialog()
        Me.panel1 = New System.Windows.Forms.Panel()
        Me.label5 = New System.Windows.Forms.Label()
        Me.SuspendLayout()

        Me.listBox1.Location = New System.Drawing.Point(16, 16)
        Me.listBox1.Size = New System.Drawing.Size(400, 95)
        Me.listBox1.TabIndex = 0

        Me.label3.Location = New System.Drawing.Point(24, 168)
        Me.label3.Text = "label3"

        Me.button1.Location = New System.Drawing.Point(96, 128)
        Me.button1.Size = New System.Drawing.Size(104, 23)
        Me.button1.Text = "Show Next Image"

        Me.button2.Location = New System.Drawing.Point(208, 128)
        Me.button2.Size = New System.Drawing.Size(104, 23)
        Me.button2.Text = "Remove Image"

        Me.button3.Location = New System.Drawing.Point(320, 128)
        Me.button3.Text = "Clear List"

        Me.button4.Location = New System.Drawing.Point(16, 128)
        Me.button4.Text = "Open Image"

        Me.pictureBox1.Location = New System.Drawing.Point(328, 232)
        Me.pictureBox1.Size = New System.Drawing.Size(336, 192)

        Me.imageList1.ImageSize = New System.Drawing.Size(16, 16)
        Me.imageList1.TransparentColor = System.Drawing.Color.Transparent

        Me.panel1.Location = New System.Drawing.Point(8, 240)
        Me.panel1.Size = New System.Drawing.Size(296, 184)

        Me.label5.Location = New System.Drawing.Point(168, 168)
        Me.label5.Size = New System.Drawing.Size(312, 40)
        Me.label5.Text = "label5"

        Me.ClientSize = New System.Drawing.Size(672, 461)
        Me.Controls.Add(label5)
        Me.Controls.Add(panel1)
        Me.Controls.Add(pictureBox1)
        Me.Controls.Add(button4)
        Me.Controls.Add(button3)
        Me.Controls.Add(button2)
        Me.Controls.Add(button1)
        Me.Controls.Add(label3)
        Me.Controls.Add(listBox1)
        Me.ResumeLayout(False)
    End Sub

    ' Display the image.
    Private Sub button1_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button1.Click

        If imageList1.Images.Empty <> True Then
            If imageList1.Images.Count - 1 > currentImage Then
                currentImage += 1
            Else
                currentImage = 0
            End If
            panel1.Refresh()

            ' Draw the image in the panel.
            imageList1.Draw(myGraphics, 10, 10, currentImage)

            ' Show the image in the PictureBox.
            pictureBox1.Image = imageList1.Images(currentImage)
            label3.Text = "Current image is " + currentImage.ToString
            listBox1.SelectedIndex = currentImage
            label5.Text = "Image is " + listBox1.Text
        End If
    End Sub

    ' Remove the image.
    Private Sub button2_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button2.Click

        imageList1.Images.RemoveAt(listBox1.SelectedIndex)
        listBox1.Items.Remove(listBox1.SelectedItem)
    End Sub

    ' Clear all images.
    Private Sub button3_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button3.Click
        imageList1.Images.Clear()
        listBox1.Items.Clear()
    End Sub

    ' Find an image.
    Private Sub button4_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button4.Click

        openFileDialog1.Multiselect = True
        If openFileDialog1.ShowDialog() = DialogResult.OK Then
            If Not (openFileDialog1.FileNames Is Nothing) Then
                Dim i As Integer
                For i = 0 To openFileDialog1.FileNames.Length - 1
                    addImage(openFileDialog1.FileNames(i))
                Next i
            Else
                addImage(openFileDialog1.FileName)
            End If
        End If
    End Sub

    Private Sub addImage(ByVal imageToLoad As String)
        If imageToLoad <> "" Then
            imageList1.Images.Add(Image.FromFile(imageToLoad))
            listBox1.BeginUpdate()
            listBox1.Items.Add(imageToLoad)
            listBox1.EndUpdate()
        End If
    End Sub

    Public Shared Sub Main(ByVal args() As String)
        Application.Run(New Form1())
    End Sub
End Class

C#
namespace myImageRotator
{
	using System;
	using System.Drawing;
	using System.ComponentModel;
	using System.Windows.Forms;
 
	public class Form1 : System.Windows.Forms.Form
	{
		private System.ComponentModel.IContainer components;
		private System.Windows.Forms.ListBox listBox1;
		private System.Windows.Forms.Label label3;
		private System.Windows.Forms.Button button1;
		private System.Windows.Forms.Button button2;
		private System.Windows.Forms.Button button3;
		private System.Windows.Forms.Button button4;
		private System.Windows.Forms.PictureBox pictureBox1;
		private System.Windows.Forms.ImageList imageList1;
		private System.Windows.Forms.OpenFileDialog openFileDialog1;
		protected Graphics myGraphics;
		private System.Windows.Forms.Panel panel1;
		private System.Windows.Forms.Label label5;
		private int currentImage = 0;
 
		public Form1()
		{
			InitializeComponent();
			imageList1 = new ImageList () ;

			// The default image size is 16 x 16, which sets up a larger
			// image size. 
			imageList1.ImageSize = new Size(255,255);
			imageList1.TransparentColor = Color.White;

			// Assigns the graphics object to use in the draw options.
			myGraphics = Graphics.FromHwnd(panel1.Handle);
		}
 
        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.label3 = new System.Windows.Forms.Label();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.button3 = new System.Windows.Forms.Button();
            this.button4 = new System.Windows.Forms.Button();
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            this.imageList1 = new System.Windows.Forms.ImageList(this.components);
            this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
            this.panel1 = new System.Windows.Forms.Panel();
            this.label5 = new System.Windows.Forms.Label();
            this.SuspendLayout();

            this.listBox1.Location = new System.Drawing.Point(16, 16);
            this.listBox1.Size = new System.Drawing.Size(400, 95);
            this.listBox1.TabIndex = 0;

            this.label3.Location = new System.Drawing.Point(24, 168);
            this.label3.Text = "label3";

            this.button1.Location = new System.Drawing.Point(96, 128);
            this.button1.Size = new System.Drawing.Size(104, 23);
            this.button1.Text = "Show Next Image";
            this.button1.Click += new System.EventHandler(this.button1_Click);

            this.button2.Location = new System.Drawing.Point(208, 128);
            this.button2.Size = new System.Drawing.Size(104, 23);
            this.button2.Text = "Remove Image";
            this.button2.Click += new System.EventHandler(this.button2_Click);

            this.button3.Location = new System.Drawing.Point(320, 128);
            this.button3.Text = "Clear List";
            this.button3.Click += new System.EventHandler(this.button3_Click);

            this.button4.Location = new System.Drawing.Point(16, 128);
            this.button4.Text = "Open Image";
            this.button4.Click += new System.EventHandler(this.button4_Click);

            this.pictureBox1.Location = new System.Drawing.Point(328, 232);
            this.pictureBox1.Size = new System.Drawing.Size(336, 192);

            this.imageList1.ImageSize = new System.Drawing.Size(16, 16);
            this.imageList1.TransparentColor = System.Drawing.Color.Transparent;

            this.panel1.Location = new System.Drawing.Point(8, 240);
            this.panel1.Size = new System.Drawing.Size(296, 184);

            this.label5.Location = new System.Drawing.Point(168, 168);
            this.label5.Size = new System.Drawing.Size(312, 40);
            this.label5.Text = "label5";

            this.ClientSize = new System.Drawing.Size(672, 461);
            this.Controls.Add(this.label5);
            this.Controls.Add(this.panel1);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.button4);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.label3);
            this.Controls.Add(this.listBox1);
            this.ResumeLayout(false);
        }

        // Display the image.
        private void button1_Click (object sender, System.EventArgs e)
		{
			if(imageList1.Images.Empty != true)
			{
				if(imageList1.Images.Count-1 > currentImage)
				{
					currentImage++;
				}
				else
				{
					currentImage=0;
				}
				panel1.Refresh();
                
                // Draw the image in the panel.
				imageList1.Draw(myGraphics,10,10,currentImage);

                // Show the image in the PictureBox.
				pictureBox1.Image = imageList1.Images[currentImage];
				label3.Text = "Current image is " + currentImage ;
				listBox1.SelectedIndex = currentImage;
				label5.Text = "Image is " + listBox1.Text ;
            }
		}
 
        // Remove the image.
		private void button2_Click (object sender, System.EventArgs e)
		{
			imageList1.Images.RemoveAt(listBox1.SelectedIndex);
			listBox1.Items.Remove(listBox1.SelectedItem);
		}
 
        // Clear all images.
		private void button3_Click (object sender, System.EventArgs e)
		{
			imageList1.Images.Clear();
			listBox1.Items.Clear();
		}
 
        // Find an image.
		private void button4_Click (object sender, System.EventArgs e)
		{
			openFileDialog1.Multiselect = true ;
			if(openFileDialog1.ShowDialog() == DialogResult.OK)
			{
				if (openFileDialog1.FileNames != null)
				{
					for(int i =0 ; i < openFileDialog1.FileNames.Length ; i++ )
					{
						addImage(openFileDialog1.FileNames[i]);
					}
				}
				else
					addImage(openFileDialog1.FileName);
			}
		}
 
		private void addImage(string imageToLoad)
		{
			if (imageToLoad != "")
			{
				imageList1.Images.Add(Image.FromFile(imageToLoad));
				listBox1.BeginUpdate();
				listBox1.Items.Add(imageToLoad);
				listBox1.EndUpdate();
			}
		}
 
        public static void Main(string[] args) 
		{
			Application.Run(new Form1());
		}
	}
}

C++
namespace myImageRotator
#using <System.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
{
    using namespace System;
    using namespace System::Drawing;
    using namespace System::ComponentModel;
    using namespace System::Windows::Forms;

    public ref class Form1 : public System::Windows::Forms::Form
    {
    private:
        System::ComponentModel::IContainer^ components;
    private:
        System::Windows::Forms::ListBox^ listBox1;
    private:
        System::Windows::Forms::Label^ label3;
    private:
        System::Windows::Forms::Button^ button1;
    private:
        System::Windows::Forms::Button^ button2;
    private:
        System::Windows::Forms::Button^ button3;
    private:
        System::Windows::Forms::Button^ button4;
    private:
        System::Windows::Forms::PictureBox^ pictureBox1;
    private:
        System::Windows::Forms::ImageList^ imageList1;
    private:
        System::Windows::Forms::OpenFileDialog^ openFileDialog1;
    protected:
        Graphics^ myGraphics;
    private:
        System::Windows::Forms::Panel^ panel1;
    private:
        System::Windows::Forms::Label^ label5;
    private:
        int currentImage;

    public:
        Form1()
        {
            InitializeComponent();
            imageList1 = gcnew ImageList () ;
            currentImage = 0;

            // The default image size is 16 x 16, which sets up a larger
            // image size. 
            imageList1->ImageSize = System::Drawing::Size(255,255);
            imageList1->TransparentColor = Color::White;

            // Assigns the graphics object to use in the draw options.
            myGraphics = Graphics::FromHwnd(panel1->Handle);
        }

    private:
        void InitializeComponent()
        {
            this->components = gcnew System::ComponentModel::Container();
            this->listBox1 = gcnew System::Windows::Forms::ListBox();
            this->label3 = gcnew System::Windows::Forms::Label();
            this->button1 = gcnew System::Windows::Forms::Button();
            this->button2 = gcnew System::Windows::Forms::Button();
            this->button3 = gcnew System::Windows::Forms::Button();
            this->button4 = gcnew System::Windows::Forms::Button();
            this->pictureBox1 = gcnew System::Windows::Forms::PictureBox();
            this->imageList1 = gcnew System::Windows::Forms::ImageList(this->components);
            this->openFileDialog1 = gcnew System::Windows::Forms::OpenFileDialog();
            this->panel1 = gcnew System::Windows::Forms::Panel();
            this->label5 = gcnew System::Windows::Forms::Label();
            this->SuspendLayout();

            this->listBox1->Location = System::Drawing::Point(16, 16);
            this->listBox1->Size = System::Drawing::Size(400, 95);
            this->listBox1->TabIndex = 0;

            this->label3->Location = System::Drawing::Point(24, 168);
            this->label3->Text = "label3";

            this->button1->Location = System::Drawing::Point(96, 128);
            this->button1->Size = System::Drawing::Size(104, 23);
            this->button1->Text = "Show Next Image";
            this->button1->Click += gcnew System::EventHandler(this,&Form1::button1_Click);

            this->button2->Location = System::Drawing::Point(208, 128);
            this->button2->Size = System::Drawing::Size(104, 23);
            this->button2->Text = "Remove Image";
            this->button2->Click += gcnew System::EventHandler(this,&Form1::button2_Click);

            this->button3->Location = System::Drawing::Point(320, 128);
            this->button3->Text = "Clear List";
            this->button3->Click += gcnew System::EventHandler(this,&Form1::button3_Click);

            this->button4->Location = System::Drawing::Point(16, 128);
            this->button4->Text = "Open Image";
            this->button4->Click += gcnew System::EventHandler(this,&Form1::button4_Click);

            this->pictureBox1->Location = System::Drawing::Point(328, 232);
            this->pictureBox1->Size = System::Drawing::Size(336, 192);

            this->imageList1->ImageSize = System::Drawing::Size(16, 16);
            this->imageList1->TransparentColor = System::Drawing::Color::Transparent;

            this->panel1->Location = System::Drawing::Point(8, 240);
            this->panel1->Size = System::Drawing::Size(296, 184);

            this->label5->Location = System::Drawing::Point(168, 168);
            this->label5->Size = System::Drawing::Size(312, 40);
            this->label5->Text = "label5";

            this->ClientSize = System::Drawing::Size(672, 461);
            this->Controls->Add(this->label5);
            this->Controls->Add(this->panel1);
            this->Controls->Add(this->pictureBox1);
            this->Controls->Add(this->button4);
            this->Controls->Add(this->button3);
            this->Controls->Add(this->button2);
            this->Controls->Add(this->button1);
            this->Controls->Add(this->label3);
            this->Controls->Add(this->listBox1);
            this->ResumeLayout(false);
        }

        // Display the image.
    private:
        void button1_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            if(imageList1->Images->Empty != true)
            {
                if(imageList1->Images->Count-1 > currentImage)
                {
                    currentImage++;
                }
                else
                {
                    currentImage=0;
                }
                panel1->Refresh();

                // Draw the image in the panel.
                imageList1->Draw(myGraphics,10,10,currentImage);

                // Show the image in the PictureBox.
                pictureBox1->Image = imageList1->Images[currentImage];
                label3->Text = "Current image is " + currentImage ;
                listBox1->SelectedIndex = currentImage;
                //				label5->Text = "Image is " + listBox1->Text ;
                label5->Text = String::Concat("Image is ",listBox1->Text);
            }
        }

        // Remove the image.
    private:
        void button2_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            imageList1->Images->RemoveAt(listBox1->SelectedIndex);
            listBox1->Items->Remove(listBox1->SelectedItem);
        }

        // Clear all images.
    private:
        void button3_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            imageList1->Images->Clear();
            listBox1->Items->Clear();
        }

        // Find an image.
    private:
        void button4_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            openFileDialog1->Multiselect = true ;
            if(openFileDialog1->ShowDialog() == System::Windows::Forms::DialogResult::OK)
            {
                if (openFileDialog1->FileNames != nullptr)
                {
                    for(int i =0 ; i < openFileDialog1->FileNames->Length ; i++ )
                    {
                        addImage(openFileDialog1->FileNames[i]);
                    }
                }
                else
                    addImage(openFileDialog1->FileName);
            }
        }

    private:
        void addImage(String^ imageToLoad)
        {
            if (imageToLoad != "")
            {
                imageList1->Images->Add(Image::FromFile(imageToLoad));
                listBox1->BeginUpdate();
                listBox1->Items->Add(imageToLoad);
                listBox1->EndUpdate();
            }
        }

    public:
        static void Main(array<String^>^ /*args*/) 
        {
            Application::Run(gcnew Form1());
        }
    };

}
int main(){
    myImageRotator::Form1::Main(nullptr);
}

J#
package myImageRotator; 

import System.*;
import System.Drawing.*;
import System.ComponentModel.*;
import System.Windows.Forms.*;

public class Form1 extends System.Windows.Forms.Form
{
    protected Container components;
    protected ListBox listBox1;
    protected Label label2;
    protected Label label3;
    protected Label label5;
    protected PictureBox pictureBox1;
    protected Button button1;
    protected Button button2;
    protected Button button3;
    protected Button button4;
    protected Panel panel1;
    protected ImageList imageList1;
    protected Graphics myGraphics;
    protected OpenFileDialog openFileDialog1;
    private int currentImage = 0;

    public Form1()
    {
        InitializeComponent();
        imageList1 = new ImageList();
        // The default image size is 16 x 16, which sets up a larger
        // image size. 
        imageList1.set_ImageSize(new Size(255, 255));
        imageList1.set_TransparentColor(Color.get_White());
        // Assigns the graphics object to use in the draw options.
        myGraphics = Graphics.FromHwnd(panel1.get_Handle());
    } //Form1

    protected void Dispose(boolean disposing)
    {
        if (disposing) {
            if (components != null) {
                components.Dispose();
            }
        }
        super.Dispose(disposing);
    } //Dispose

    private void InitializeComponent()
    {
        // Initializations for listBox1, label2, pictureBox1,
        // button2, button3, panel1, openFileDialog1, button4, label1, 
        // button1, and imageList1.
    } //InitializeComponent

    protected void button1_Click(Object sender, System.EventArgs e)
    {
        DisplayNextImage();
    } //button1_Click

    protected void button2_Click(Object sender, System.EventArgs e)
    {
        imageList1.get_Images().RemoveAt(listBox1.get_SelectedIndex());
        listBox1.get_Items().Remove(new Integer(listBox1.
            get_SelectedIndex()));
    } //button2_Click

    protected void button3_Click(Object sender, System.EventArgs e)
    {
        imageList1.get_Images().Clear();
    } //button3_Click

    protected void button4_Click(Object sender, System.EventArgs e)
    {
        openFileDialog1.set_Multiselect(true);
        if (openFileDialog1.ShowDialog().Equals(get_DialogResult().OK)) {
            if (openFileDialog1.get_FileNames() != null) {
                for (int i = 0; i < openFileDialog1.get_FileNames().length;
                    i++) {
                    AddImage(openFileDialog1.get_FileNames()[i]);
                }
            }
            else {
                AddImage(openFileDialog1.get_FileName());
            }
        }
    } //button4_Click

    private void AddImage(String imageToLoad)
    {
        if (!(imageToLoad.Equals(""))) {
            imageList1.get_Images().Add(Image.FromFile(imageToLoad));
            listBox1.BeginUpdate();
            listBox1.get_Items().Add(imageToLoad);
            listBox1.EndUpdate();
        }
    } //AddImage

    void DisplayNextImage()
    {
        if (imageList1.get_Images().get_Empty() != true) {
            if (imageList1.get_Images().get_Count() - 1 < currentImage) {
                currentImage++;
            }
            else {
                currentImage = 0;
            }
            panel1.Refresh();
            imageList1.Draw(myGraphics, 10, 10, currentImage);
            pictureBox1.set_Image(imageList1.get_Images().
                get_Item(currentImage));
            label3.set_Text("Current image is " + currentImage);
            listBox1.set_SelectedIndex(currentImage);
            label5.set_Text("Image is " + listBox1.get_Text());
        }
    } //DisplayNextImage

    public static void main(String[] args)
    {
        Application.Run(new Form1());
    } //main
} //Form1

Gerarchia di ereditarietà

System.Object
   System.MarshalByRefObject
     System.ComponentModel.Component
      System.Windows.Forms.ImageList
Codice thread safe

I membri statici pubblici (Shared in Visual Basic) di questo tipo sono validi per le operazioni multithreading. I membri di istanza non sono garantiti come thread safe.
Piattaforme

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile per Pocket PC, Windows Mobile per Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework non supporta tutte le versioni di ciascuna piattaforma. Per un elenco delle versioni supportate, vedere Requisiti di sistema.

Informazioni sulla versione

.NET Framework

Supportato in: 2.0 1.1 1.0

.NET Compact Framework

Supportato in: 2.0 1.0
Vedere anche