c# - After setting tree node height, treeview scroll incorrectly -

    public form2()     {         initializecomponent();     }      private void form2_load(object sender, eventargs e)     {         dictionary<int, treenode> map = new dictionary<int, treenode>();         (int = 0; < 100; i++)         {             treenode node = new treenode(i.tostring());             if (i % 10 == 0)                 _tree.nodes.add(node);             map.add(i, node);             if (i % 10 != 0)             {                 map[convert.toint32(math.floor(i / 10.0)) * 10].nodes.add(node);                 node.setnodeheight(2);             }         }     } }  public static class treeviewextendmethod {     [structlayout(layoutkind.sequential)]     struct tvitemex     {         public mask mask;         public intptr item;         public uint state;         public uint statemask;         public intptr psztext;         public int cchtextmax;         public int iimage;         public int iselectedimage;         public int ichildren;         public intptr lparam;         public int iintegral;          // ... plus windows 6+ crap     }      [flags]     enum mask : uint     {         text = 1,         image = 2,         param = 4,         state = 8,         handle = 16,         selectedimage = 32,         children = 64,         integral = 128,     }     public static int getnodeheight(this treenode tn)     {         tvitemex tvix = new tvitemex();         tvix.mask = mask.handle | mask.integral;         tvix.item = tn.handle;         tvix.iintegral = 0;         intptr hparam=marshal.allochglobal(marshal.sizeof(tvix));         marshal.structuretoptr(tvix, hparam, false);         win32.sendmessage(tn.treeview.handle, win32.tvm_getitem, intptr.zero, hparam);         return tvix.iintegral;     }      public static void setnodeheight(this treenode tn, int height)     {         tvitemex tvix = new tvitemex();         tvix.mask = mask.handle | mask.integral;         tvix.item = tn.handle;         tvix.iintegral = height;         intptr hparam=marshal.allochglobal(marshal.sizeof(tvix));         marshal.structuretoptr(tvix, hparam, false);         win32.sendmessage(tn.treeview.handle, win32.tvm_setitem, intptr.zero, hparam);     } } 

the above sample code, after using pinv change node height manually, when click in bottom of scroll bar, treeview scroll should not scroll @ click.

at first, think may caused scroll bar, doesn't work expected after set scroll msg para (8) end scroll. @ last, while catching scroll msg (0x115), exits wndproc, , works. have no idea going on can't find msg can cancel scroll except setting wparam 8 not work.

i find solution, though not elegant, should works. here solution,

        protected override void wndproc(ref message m)     {         if (m.msg == 0x115)         {             if (((int)m.wparam & 5) == (5) ||                 ((int)m.wparam & 4) == (4)                 )             {                 int para = (int)m.wparam;                 int temp = (para - (para % 2 == 0 ? 4 : 5)) >> 16;                  // store current position, if position doesn't change, no need handle                 if (temp == pos)                     return;                 else                     pos = temp;             }             if (((int)m.wparam & 8) == 8)                 return;              //debug.writeline(m.wparam);             //if (disablescroll)             //    return;             //    //m.wparam = (intptr)8;             //scrollinfo si = new scrollinfo();             //si.cbsize = marshal.sizeof(si);             //si.fmask = (int)(scrollinfomask.sif_pos | scrollinfomask.sif_page | scrollinfomask.sif_range | scrollinfomask.sif_trackpos);             //getscrollinfo(this.handle, 1, ref si);             ////debug.writeline(string.format("max pos:{0}, min pos: {1}", si.nmin, si.nmax));             //debug.writeline(string.format("wparam:{0} hparam:{1}", m.wparam, m.lparam));             //debug.writeline(string.format("it page size: {0}, position: {1}, range: {2}, track pos: {3}", si.npage, si.npos, si.npage, si.ntrackpos));             //if (si.npage + math.max(si.npos, si.ntrackpos) >= si.nmax)             //{             //    return;             //}         }         base.wndproc(ref m);     }