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Load image in Picture Box when User Control shows to user

I want to show a lot of images in a form using User Control, but it's very slow and takes a lot of system memory.
How can I load image in Picture Box when User Control shows to user?
I wrote this sample code. It works fine for 700 images, but I am still looking for best solution.
Bitmap myBitmap;
Image myThumbnail;
foreach (var item in queryMatchingFiles)
{
Image.GetThumbnailImageAbort myCallback = new Image.GetThumbnailImageAbort(ThumbnailCallback);
myBitmap = new Bitmap(item);
myThumbnail = myBitmap.GetThumbnailImage(120, 183, myCallback, IntPtr.Zero);
flowLayoutPanel1.Controls.Add(new PictureBox {
Image = myThumbnail,
Width = 120,
Height = 183,
BackgroundImageLayout = ImageLayout.Stretch
});
count++;
myBitmap = null;
myThumbnail = null;
}
public bool ThumbnailCallback()
{
return false;
}

Determine if two images are identical

Is there any way to determine if two images are identical?
I want to change an image every time my timer ticks (animation).
But, I need to see which image is displaying, so is there any way to compare 2 images
to do what I want?
if (myImage.Flags == (Image.FromFile(#"Images/Enemy.png").Flags))
{
myImage = Image.FromFile(#"Images/Enemy2.png");
}
else
{
myImage = Image.FromFile(#"Images/Enemy.png");
}

Don't compare the images, just maintain the index of the current image in a variable.
Here's an example that works for any number of images:
private int _currentImageIndex;
private string[] _imagePaths =
{
"Images/Enemy.png",
"Images/Enemy2.png",
"Images/Enemy3.png",
};
...
void NextImage()
{
// Dispose the current image
Image img = pictureBox1.Image;
pictureBox1.Image = null;
if (img != null)
img.Dispose();
// Show the next image
_currentImageIndex = (_currentImageIndex + 1) % _imagePaths.Length;
string path = _imagePaths[_currentImageIndex];
pictureBox1.Image = Image.FromFile(path);
}

I'd try to compare ImageLocation. Although it doesn't work if you have your pictures as resources.
if (PictureBox1.ImageLocation == PictureBox2.ImageLocation)
{
}
See my question:
Dynamically changing image in a picturebox

Here goes simple answer.
In case of just 2 images, use flag
// field, true if enemy2.png is loaded
bool _image2;
// somewhere
if(_image2)
{
myImage = Image.FromFile(#"Images/Enemy.png");
_image2 = false;
}
else
{
myImage = Image.FromFile(#"Images/Enemy2.png");
_image2 = true;
}

Image Slider in C#?

I want to create a simple image slideshow, when the timer switch, it will switch to the next index of the picturebox (and will loop) but with a fade effect. How can it be done in C#?
Current Code doesn't switch images? And also - how can I create the fade ffect?
I created a simple timer with 5,000ms interval, enabled it on start.
private void timerImage_Tick(object sender, EventArgs e)
{
if (pictureBox1.Image.Equals(InnovationX.Properties.Resources._1))
{
pictureBox1.Image = InnovationX.Properties.Resources._2;
}
else if (pictureBox1.Image.Equals(InnovationX.Properties.Resources._2))
{
pictureBox1.Image = InnovationX.Properties.Resources._3;
}
else
{
pictureBox1.Image = InnovationX.Properties.Resources._1;
}
}

You can't compare Bitmap loaded from resource in this manner. Every time you get image from resource (in your case using property InnovationX.Properties.Resources._1) you will get new instance of Bitmap class. Comparing two different instances of Bitmap classes will always result in false, even if they contains same image.
Bitmap a = InnovationX.Properties.Resources._1; // create new bitmap with image 1
Bitmap b = InnovationX.Properties.Resources._1; // create another new bitmap with image 1
bool areSameInstance = a == b; // will be false
If you load you images from resources to member variables (e.g. in Load event).
// load images when you create a form
private Bitmap image1 = InnovationX.Properties.Resources._1;
private Bitmap image2 = InnovationX.Properties.Resources._2;
private Bitmap image3 = InnovationX.Properties.Resources._3;
// assing and compare loaded images
private void timerImage_Tick(object sender, EventArgs e)
{
if (pictureBox1.Image == image1)
{
pictureBox1.Image = image2;
}
else if (pictureBox1.Image == image2)
{
pictureBox1.Image = image3;
}
else
{
pictureBox1.Image = image1;
}
}
And after that, rewrite that code using array :)
Image[] images = new {
InnovationX.Properties.Resources._1,
InnovationX.Properties.Resources._2,
InnovationX.Properties.Resources._3
};

Getting image from clipboard - black when screenshots appear?

I am using WPF to display the image in the clipboard. This works fine when going to Paint and copying something there, but when I hit "Print screen" to take a screenshot, the output there is just a black image, that has the same dimensions as the screen.
How come?
The code for taking data from the clipboard is as follows (yes, I do in fact want to use raw API calls).
...
case CF_BITMAP:
BitmapSource source = null;
System.Drawing.Bitmap finalBitmap = null;
IntPtr destinationHdc = CreateCompatibleDC(IntPtr.Zero);
if (destinationHdc != null)
{
IntPtr sourceHdc = CreateCompatibleDC(IntPtr.Zero);
if (sourceHdc != null)
{
if (OpenClipboard(MainWindow.Handle))
{
IntPtr sourceBitmap = GetClipboardData((uint)clipboardFormat);
SelectObject(sourceHdc, sourceBitmap);
BITMAP bmp;
GetObject(sourceBitmap, Marshal.SizeOf(typeof(BITMAP)), out bmp);
IntPtr destinationBitmap = CreateCompatibleBitmap(destinationHdc, bmp.bmWidth, bmp.bmHeight);
SelectObject(destinationHdc, destinationBitmap);
BitBlt(destinationHdc, 0, 0, bmp.bmWidth, bmp.bmHeight, sourceHdc, 0, 0, 0x00CC0020);
CloseClipboard();
finalBitmap = System.Drawing.Bitmap.FromHbitmap(destinationBitmap);
}
DeleteDC(sourceHdc);
}
DeleteDC(destinationHdc);
}
if (finalBitmap != null && ((LastData == null || !(LastData is System.Drawing.Bitmap)) || !finalBitmap.EqualsTo((System.Drawing.Bitmap)LastData)))
{
source = BitmapToSource(finalBitmap);
if (LastData == null || source != LastData)
{
tile = new ImageTile();
(tile as ImageTile).Image.Source = source;
tile.RawData = finalBitmap;
}
}
return tile;
...

I ended up using the inbuilt framework method instead, Clipboard.GetImage(). The WPF version of it seems to work better than the Windows Forms one.

Drawing Transparent Images

I'm writing a CSS sprite engine in C#, however I'm having a few issues. I create the master image, set all the properties to that then iterate the sprites and draw those to the master image. However when I come to save the master image it only appears to be just the empty master image with transparent background and none of the sprites. I'm very confused at where I'm going wrong.
The code I'm using is:
// Work out the width/height required
int max_width = 0;
int max_height = 0;
foreach(SpriteInformation sprite in sprites) {
if (max_width < (sprite.Left + greatest_width)) max_width = sprite.Left + greatest_width;
if (max_height < (sprite.Top + greatest_height)) max_height = sprite.Top + greatest_height;
}
// Create new master bitmap
Bitmap bitmap = new Bitmap(max_width,max_height,PixelFormat.Format32bppArgb);
Graphics graphics = Graphics.FromImage(bitmap);
// Set background color
SolidBrush brush;
if (cbxBackground.Checked) {
if (txtColor.Text == "") {
brush = new SolidBrush(Color.Black);
} else {
brush = new SolidBrush(pnlColor.BackColor);
}
} else {
if (txtColor.Text == "") {
brush = new SolidBrush(Color.White);
} else {
brush = new SolidBrush(pnlColor.BackColor);
}
}
//graphics.FillRectangle(brush,0,0,bitmap.Width,bitmap.Height);
bitmap.MakeTransparent(brush.Color);
graphics.Clear(brush.Color);
// Copy images into place
ImageAttributes attr = new ImageAttributes();
//attr.SetColorKey(brush.Color,brush.Color);
foreach(SpriteInformation sprite in sprites) {
Rectangle source = new Rectangle(0,0,sprite.Width,sprite.Height);
Rectangle dest = new Rectangle(sprite.Left,sprite.Top,sprite.Width,sprite.Height);
graphics.DrawImage(sprite.Sprite,dest,0,0,sprite.Width,sprite.Height,GraphicsUnit.Pixel,attr);
}
// Save image
string format = ddlFormat.Items[ddlFormat.SelectedIndex].ToString();
if (format == "PNG") {
dlgSave.Filter = "PNG Images|*.png|All Files|*.*";
dlgSave.DefaultExt = ",png";
if (dlgSave.ShowDialog() == DialogResult.OK) {
bitmap.Save(dlgSave.FileName,ImageFormat.Png);
}
} else if (format == "JPEG") {
} else {
}

What are sprite.Left and Top? If they aren't 0 that may be a problem. I think you have dest and source the wrong way round?
http://msdn.microsoft.com/en-us/library/ms142045.aspx
Try a simpler DrawImage variant if you haven't already.
e.g. DrawImage(sprite.Sprite,0,0)

You draw to "graphics", but then then you save "bitmap"? I'm not sure if that graphics internally works with your original "bitmap" object...