我想在form上規劃一小區塊來劃線,如RECT(0,0,100,100)四方之內. 但當我下指令 Canvas->MoveTo(0,0); Canvas->LineTo(200,200); 線條會一直劃到POINT(200,200); 我該如何讓它只會劃到POINT(100,100), 超出RECT(0,0,100,100)以外不劃, 記得dos環境有setviewport可用, 但在windows環境卻不管用.我測過 SetViewportExtEx和SetWindowExtEx, 但未測出來,麻煩各位先進幫我測一下,謝謝.

引言: 我想在form上規劃一小區塊來劃線,如RECT(0,0,100,100)四方之內. 但當我下指令 Canvas->MoveTo(0,0); Canvas->LineTo(200,200); 線條會一直劃到POINT(200,200); 我該如何讓它只會劃到POINT(100,100), 超出RECT(0,0,100,100)以外不劃, 記得dos環境有setviewport可用, 但在windows環境卻不管用.我測過 SetViewportExtEx和SetWindowExtEx, 但未測出來,麻煩各位先進幫我測一下,謝謝.

SelectClipRgn ABCD分開看的懂，連起來像鬼劃符~~!!!

非常感謝jest0024大哥,己經ok.

 
    HRGN MyRgn;        MyRgn = ::CreateRectRgn(0,0,100,100);
    ::SelectClipRgn(Canvas->Handle,MyRgn);
    Canvas->MoveTo(0,0);
    Canvas->LineTo(250,250);        ::SelectClipRgn(Canvas->Handle,NULL);
    ::DeleteObject(MyRgn);