C#

unsafe static byte[] getBytes(BitmapData data)
{
	byte* firstByte = (byte*)data.Scan0.ToPointer();
	int size = data.Stride * data.Height;
	byte[] bytes = new byte[size];
	for (int i = 0; i < size; i++)
		bytes[i] = firstByte[i];
	return bytes;
}
unsafe static void setBytes(BitmapData data, byte[] bytes)
{
	byte* firstByte = (byte*)data.Scan0.ToPointer();
	int size = data.Stride * data.Height;
	for (int i = 0; i < size; i++)
		firstByte[i] = bytes[i];
}
static void Main()
{
	using (Bitmap bmp = (Bitmap)Bitmap.FromFile(@"test.bmp")) {
		BitmapData data = bmp.LockBits(new Rectangle(new Point(0), bmp.Size),
			ImageLockMode.ReadOnly, bmp.PixelFormat);
		byte[] bytes = getBytes(data);
		bmp.UnlockBits(data);
		using (Bitmap copy = new Bitmap(data.Width, data.Height, bmp.PixelFormat)) {
			data = copy.LockBits(new Rectangle(new Point(0), copy.Size),
				ImageLockMode.WriteOnly, copy.PixelFormat);
			setBytes(data, bytes);
			copy.UnlockBits(data);
			copy.Save(@"test - copy.bmp");
		}
	}
}

George_George wrote:

Are there any existing utility class to do this? Not all URLs begins with protocol part, like http://, and not all ends with /, so I feel hard when I try to write a parser by myself;

Uri uri = new Uri("http://abc.com/some/address/abc.html");
Console.WriteLine(uri.Host);

George_George wrote:

Is domain case sensitive or not? i.e. abc.com the same as ABc.Com?

George_George wrote:

I want to get top 10 elements from the Dictionary with the maximum 10 int values,

("entry1", 1);
("entry2", 2);
("entry3", 3);
("entry4", 10);
("entry5", 5);

int[] values = list.Values.ToArray();
values.Sort();
int tr = values[values.Length - 10];
List<KeyValuePair<string,int>> = list.Where(item=>item.Value>=tr).ToList();

List<KeyValuePair<string,int>> = list.Where(item=>item.Value>=tr).ToList();

George_George wrote:

From left side of the assignment, do you miss a variable name?

George_George wrote:

What does this operator mean item=>item.Value>=tr?

int[] values = dictionary.Values.ToArray();
values.Sort();
int tr = values[values.Length - 10];
List<KeyValuePair<string,int>> result = new List<KeyValuePair<string,int>>();
foreach (KeyValuePair<string,int> item in dictionary) {
   if (item.Value >= tr) {
      result.Add(item);
   }
}