hey there, i've been messing around with applying graphics to windows of other applications, using their window handles.. (if that's even possible..).
here's my code so far:
[DllImport("user32.dll")]
public static extern IntPtr GetForegroundWindow();
[DllImport("user32")]
public static extern IntPtr GetWindow(IntPtr hWnd, uint uCmd);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern int GetWindowText(IntPtr hWnd, [Out, MarshalAs(UnmanagedType.LPTStr)] StringBuilder lpString, int nMaxCount);
public Graphics g;
public IntPtr window = IntPtr.Zero; //the main handle holder
public IntPtr[] hwnd = new IntPtr[100]; //a temporary handle holder.. gave it a 100 cuz u can't know how many handles u get..
public static StringBuilder str = new StringBuilder("",100); //what da heck.. give it a 100 ;)
public Form1()
{
InitializeComponent();
}
private void button2_Click(object sender, EventArgs e)
{
if (window != IntPtr.Zero)
{
g = Graphics.FromHwnd(window);
g.DrawRectangle(new Pen(Color.Red, 1.8f), ClientRectangle.Width / 2, this.ClientRectangle.Height / 2, 10, 10);
}
else //a small debug..
{
window = this.Handle;
Graphics g = Graphics.FromHwnd(window);
g.DrawLine(new Pen(Color.Red, 1), 0,this.Height,this.Width,0);
g.DrawLine(new Pen(Color.Red, 1), 0, 0, this.Height, this.Width);
g.Dispose();
}
}
private void button1_Click(object sender, EventArgs e)
{
FindHwnd();
}
private IntPtr FindHwnd()
{
listBox1.Items.Clear();
Array.Clear(hwnd,0, hwnd.Length);
window = GetWindow(GetForegroundWindow(), 0);
while (window != IntPtr.Zero)
{
// str.Insert(0, 0);
GetWindowText(window, str, 100);
//str.Insert(100, 0); i canceled these 2 cuz it gave me an out of memory exception..
if (str.Length != 0)
listBox1.Items.Add(str);
hwnd[listBox1.Items.Count] = window;
window = GetWindow(window, 2);
}
return window;
}
private void listBox1_DoubleClick(object sender, EventArgs e)
{
window = hwnd[listBox1.SelectedIndex];
}to sum it up: u click on 1 button, and the listbox fills up with the window handles FindHwnd picked up.. the only problem i have is that i can't draw on them... can't tell why.. oddly enough, i did manage to draw at the button2_Click when i gave "window" the value of [this.handle] (the debug part in the drawing section).. so something must have gone wrong when i picked up or passed on the handles... if any1 can shed some light on this, i will appreciate it allot, thanks!
oh btw.. this is the first program i tried to write that actually does something so... excuse any improper use of w.e i put there... kina hard to figure it all out from the msdn.. no realy, try it ;)
oh yeah, and this is my first post on a forum ever so.. sorry if i did something wrong here...