A function to automatically connect two controls on a dialog box (draw a line)

void Cgasbagcdlg::linetwoctrl (CPaintDC *dc,int leftid,int rightid,cgasbagcdlg *phd) {//201506161749 in Peking University 韩晓东 compilation// Function: can be called in OnPaint, connect two control//Parameter description: Parameter 1:onpaint brush, parameter two: control 1ID, Parameter three: control 2ID, parameter four: Current window pointer//writing PROBLEM: Parameter one is MFC's class object pointer, Passing MFC class objects can only be passed as pointers or references, and parameter four gets the context//indicator line through the this pointer CRect rectl,rectr;phd->getdlgitem (leftid)->getwindowrect (& RECTL);//Gets the position of the control relative to the screen phd->screentoclient (RECTL);//convert to relative position on dialog phd->getdlgitem (rightid)->getwindowrect (&rectr);//Gets the position of the control relative to the screen phd->screentoclient (RECTR);//Convert to the relative position on the dialog uint m_rowl=rectl.bottom-rectl.top;// Left indicator height UINT m_rowr=rectr.bottom-rectr.top;//Right indicator height uint m_width=rectr.left-rectl.right;//around indicator cross spacing int m_height= ( RECTL.BOTTOM-M_ROWL/2)-(RECTR.BOTTOM-M_ROWR/2);//left or indicator middle point height difference. Phd->updatedata (FALSE);d C->moveto (RECTL.RIGHT,RECTL.BOTTOM-M_ROWL/2);//Connect two control center points Dc->lineto ( RECTL.RIGHT+M_WIDTH/2,RECTL.BOTTOM-M_ROWL/2);//Point 1dc->lineto (rectl.right+m_width/2,rectl.bottom-m_rowl/2-m_ height);//Point 2dc->lineto (RECTR.LEFT,RECTR.TOP+M_ROWR/2);//DOT 3//connection Complete}

OnPaint () in the attached project:

void Cgasbagcdlg::onpaint () {CPAINTDC DC (this),//device context for painting//TODO: Add Message Handler code here//indicator lines// First level: Linetwoctrl (&dc,idc_a_static,idc_b1_static,this); Linetwoctrl (&dc,idc_a_static,idc_b2_static,this); Linetwoctrl (&dc,idc_a_static,idc_b3_static,this); Linetwoctrl (&dc,idc_a_static,idc_b4_static,this);//Two-level Linetwoctrl (&dc,idc_b1_static,idc_c11_static,this ); Linetwoctrl (&dc,idc_b1_static,idc_c12_static,this); Linetwoctrl (&dc,idc_b2_static,idc_c21_static,this); Linetwoctrl (&dc,idc_b2_static,idc_c22_static,this); Linetwoctrl (&dc,idc_b3_static,idc_c31_static,this); Linetwoctrl (&dc,idc_b3_static,idc_c32_static,this); Linetwoctrl (&dc,idc_b4_static,idc_c41_static,this); Linetwoctrl (&dc,idc_b4_static,idc_c42_static,this); Linetwoctrl (&dc,idc_b4_static,idc_c43_static,this);//three-level Linetwoctrl (&dc,idc_c11_static,idc_d111_static, this); Linetwoctrl (&dc,idc_c11_static,idc_d112_static,this); Linetwoctrl (&dc,idc_c11_static,idc_d113_static,this); LineTwoctrl (&dc,idc_c12_static,idc_d121_static,this); Linetwoctrl (&dc,idc_c12_static,idc_d122_static,this); Linetwoctrl (&dc,idc_c12_static,idc_d123_static,this); Linetwoctrl (&dc,idc_c12_static,idc_d124_static,this); Linetwoctrl (&dc,idc_c21_static,idc_d211_static,this); Linetwoctrl (&dc,idc_c21_static,idc_d212_static,this); Linetwoctrl (&dc,idc_c21_static,idc_d213_static,this); Linetwoctrl (&dc,idc_c22_static,idc_d221_static,this); Linetwoctrl (&dc,idc_c22_static,idc_d222_static,this); Linetwoctrl (&dc,idc_c22_static,idc_d223_static,this); Linetwoctrl (&dc,idc_c31_static,idc_d311_static,this); Linetwoctrl (&dc,idc_c31_static,idc_d312_static,this);//connection complete//Do not Call Cdialogex::onpaint ()} for the drawing message

　　

A function to automatically connect two controls on a dialog box (draw a line)