Use wtl to implement irregular windows

The irregular window is also called the "special-shaped" window. Now the game's starter interface is like the perfect "Xian", "pocket westward journey", and "jian Xia" in Jinshan, very beautiful. This article describes how to use wtl to implement a "special window ".

 

1. Create a dialog project with Wizard and set the "border" attribute of the window to none (that is, there is no title bar );

2. Load bitmap:

Bool cmaindlg: loadbitmap (uint nidresource) // nidresource: The resource ID of the bitmap.
{
// Load bitmap
M_bmbitmap = new cbitmap;
If (! M_bmbitmap-> loadbitmap (nidresource ))
Return false;

Bitmap bm;
M_bmbitmap-> getbitmap (& BM );
Int W = BM. bmwidth;
Int H = BM. bmheight;

 
M_bbitmapcreated = true;
M_bbitmapexists = true;

Return true;
}

 

3. Set the drawing area:

Void cmaindlg: make‑wrgn ()
{
// Window rect-client rect
Crect rcwnd;
Getwindowrect (rcwnd );

Crgn RGN;
RGN. createrectrgn (rcwnd. Left, rcwnd. Top, rcwnd. Right, rcwnd. Bottom );

Crect rcclient;
Getclientrect (rcclient );
Clienttoscreen (rcclient );

Crgn rgnclient;
Rgnclient. createrectrgn (rcclient. Left, rcclient. Top, rcclient. Right,
Rcclient. Bottom );

RGN. combinergn (hrgn (RGN), hrgn (rgnclient), rgn_xor );

// Obtain the bitmap DC
CDC dcimage;
Dcimage. createcompatibledc (null );

Hbitmap holdbmp = dcimage. selectbitmap (* m_bmbitmap );

// Obtain the width and height of the bitmap.

Bitmap bm;
M_bmbitmap-> getbitmap (& BM );

// Obtain the window width and height.
Crect RC;
Getclientrect (RC );

// Obtain the minimum width and height.
Int width = min (BM. bmwidth, RC. Width ());
Int Height = min (BM. bmheight, RC. Height ());

// RLE (run-length)Algorithm: Row_start is the first opaque pixel found. Once the transparent pixel is found, the always-line area is created. Then row_start becomes the next opaque pixel.
Int row_start;

// Traverse all rows
For (INT y = 0; y {
// Start from scratch

Row_start = 0;

Int X;
// Traverse all columns
For (x = 0; x <width; X ++)
{
// If the pixel is transparent
If (dcimage. getpixel (x, y) = m_coltrans) // m_coltrans: transparent (the color part in the bitmap is transparent)
{
// If no opaque pixel is found, continue searching

If (row_start = x) row_start ++;
Else
{

// You have found the start and end (x) of an opaque line segment and added it to the area to be drawn.
Crgn rgnadd;
Rgnadd. createrectrgn (row_start, Y, X, Y + 1 );
RGN. combinergn (hrgn (RGN), hrgn (rgnadd), rgn_or );
Row_start = x + 1;
}
}
}

// If the last pixel is still opaque, create another region.
If (row_start! = X)
{
Crgn rgnadd;
Rgnadd. createrectrgn (row_start, Y, X, Y + 1 );
RGN. combinergn (hrgn (RGN), hrgn (rgnadd), rgn_or );
}
}

Setjavaswrgn (RGN, true );
}

 

3. process Background Erasure
Message_handler (wm_erasebkgnd, onerasebkgnd)

 

Lresult cmaindlg: onerasebkgnd (uint umsg, wparam, lparam, bool & bhandled)
{
HDC = (HDC) wparam;

// Obtain the customer region of the window.

Crect RC;
Getclientrect (RC );

// Obtain the bitmap DC
CDC dcimage;
Dcimage. createcompatibledc (HDC );
Hbitmap holdbmp = dcimage. selectbitmap (* m_bmbitmap );

// Obtain the bitmap width and height.
Bitmap bm;
M_bmbitmap-> getbitmap (& BM );

// Use the minimum width and height

Int width = min (BM. bmwidth, RC. Width ());
Int Height = min (BM. bmheight, RC. Height ());

// Draw a bitmap as the window background
Bitblt (HDC, 0, 0, RC. Width (), RC. Height (), dcimage, 0, 0, srccopy );

Dcimage. selectbitmap (holdbmp );
Dcimage. deletedc ();

Return true;
}

 

4. left-click processing (used to drag the window)
Message_handler (wm_lbuttondown, onlbuttondown)

 

Lresult cmaindlg: onlbuttondown (uint umsg, wparam, lparam, bool & bhandled)
{
Cpoint Pt (lparam );

// Fool the window so that the mouse clicks the title bar
Postmessage (wm_nclbuttondown, htcaption, makelparam (Pt. X, Pt. y ));

Return 0;
}

Shows the effect:

 

 

 

Note: the background of a randomly selected image is not pure black, so there will be burrs on the edge. You can solve this problem by clicking Photoshop.