Learn message (2): Send the wm_mousemove message

In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls, extctrls; Type tform1 = Class (tform) Panel1: tpanel; button1: tbutton; button2: tbutton; button3: tbutton; Procedure panel1mousemove (Sender: tobject; shift: tshiftstate; X, Y: integer); Procedure button1click (Sender: tobject ); procedure button2click (Sender: tobject); Procedure button3click (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} {when the mouse moves in Panel1, I did the following :} {1. Show coordinates of the mouse in Panel1} {2. show whether shift, Ctrl, ALT} procedure tform1.panel1mousemove (Sender: tobject; shift: tshiftstate; X, Y: integer); var list: tstringlist; begin list: = tstringlist. create; If ssshift in shift then list. add ('shift '); If ssctrl in shift then list. add ('ctrl '); If ssalt in shift then list. add ('alt'); If list. count> 0 then panel1.caption: = format ('% s: % d, % d', [list. commatext, X, Y]) else panel1.caption: = format ('% d, % d', [x, y]); list. free; end; {send wm_mousemove message to Panel1} {the first message parameter is 0, indicating that no secondary key is pressed} {the second message parameter is 0, it is equivalent to moving the mouse to the (0, 0) Coordinate} procedure tform1.button1click (Sender: tobject); begin panel1.perform (wm_mousemove, 0, 0); end; {send wm_mousemove message to Panel1} {the second message parameter represents the mouse Coordinate Position in the wm_mousemove message. The parameter is a 32-bit integer and the 16-bit lower is X, the 16-bit height is y} {the coordinates given here are the control center point} procedure tform1.button2click (Sender: tobject); var X, Y, lparam: integer; begin X: = panel1.clientwidth Div 2; Y: = panel1.clientheight Div 2; lparam: = y SHL 16 or X; panel1.perform (wm_mousemove, 0, lparam); end; {send wm_mousemove message to Panel1} {the first parameter of the message indicates which secondary key is being pressed and the state of the mouse} {the message sent here is: press shift and move the cursor to (20, 10)} procedure tform1.button3click (Sender: tobject); const x = 20; y = 10; begin panel1.perform (wm_mousemove, mk_shift, y SHL 16 or X); end.
 
   
 

Form file:

 Object form1: tform1 left = 0 Top = 0 caption = 'form1 'clientheight = 198 clientwidth = 255 color = clbtnface font. charset = default_charset font. color = clwindowtext font. height =-11 font. name = 'tahoma 'font. style = [] oldcreateorder = false pixelsperinch = 96 textheight = 13 object Panel1: tpanel left = 8 Top = 8 width = 237 Height = 121 caption = 'panel1' taborder = 0 onmousemove = panel1mousemove end object button1: tbutton left = 8 Top = 152 width = 75 Height = 25 caption = 'button1' taborder = 1 onclick = button1click end object button2: tbutton left = 89 Top = 152 width = 75 Height = 25 caption = 'button2' taborder = 2 onclick = button2click end object button3: tbutton left = 170 Top = 152 width = 75 Height = 25 caption = 'button3' taborder = 3 onclick = button3click endend