利用plus美化和模拟滚动条代替listbox的系统滚动条

参考jacen在另外一个listview模拟滚动条的帖子里提供的简化代码, 这个listbox滚动条也可以再次简化.

将plusExbar模拟库里面增加如下代码, 然后winform里面就可以不必写listbox的wndproc回调了.

listbox.wndproc = function(hwnd,message,wParam,lParam){
    if(message == 0x20A/*_WM_MOUSEWHEEL*/){ 
        if( ::HIWORD(wParam) & 0x8000  ){ 
            if( plus.stepProgress(-1,true) ){
                ::SendMessageInt(listbox.hwnd, 0x115/*_WM_VSCROLL*/, 1, 0);
            }  
        }
        else { 
            ::SendMessageInt(listbox.hwnd, 0x115/*_WM_VSCROLL*/, 0, 0);
            plus.stepProgress(1,true)
             
        }
        return 0;
    };
}

感谢: The Machine 提供修改版本

import win.ui;
/*DSG{{*/
var winform = win.form(text="aardio form";right=759;bottom=469)
winform.add(
button={cls="button";text="添加50项目";left=499;top=128;right=640;bottom=167;z=2};
button2={cls="button";text="清空";left=502;top=202;right=643;bottom=241;z=3};
button3={cls="button";text="删除某项";left=502;top=270;right=643;bottom=309;z=4};
listbox={cls="listbox";left=81;top=32;right=366;bottom=411;items={};z=1}
)
/*}}*/

import win.ui.ctrl.plus;
    class scrollbarEx{
        ctor(ctrl,iWidth = 10,itemHeight = 15){//listbox,滚动条宽度、列表项行高
            if(!ctrl[["hwnd"]]) error("参数必须是窗口对象",2);	
            this = ctrl;
            var rc = this.getRect()
            rc.bottom += itemHeight;
            this.modifyStyle(,0x4000000/*_WS_CLIPSIBLINGS*/);
            var dyPlus = winform.add(
                plus = {cls="plus";left = rc.right-iWidth;top=rc.top; bottom=rc.bottom;width = iWidth;hide=1;bgcolor=-8750470;border={radius=5};color=14587648;foreTop=50;paddingLeft=1;paddingRight=1;dr=1;dt=1;db=1;z=1}
            );
            sb = dyPlus.plus;	
            ..win.setPos(sb.hwnd,,,,,0);
            ..win.setPos(this.hwnd,,,,,1);
            sb.skin(style)
            var max = this.count * itemHeight; //显示区域高度 = 总项目得高度
               var overstep = (max - rc.height()) / itemHeight//溢出表项计数 = 超出窗口显示，额外的项目
               var thumb = ..math.floor(rc.height() / max * sb.height);	
               var trackPos = 	overstep;
            sb.setTrackbarRange(0,overstep);
            sb.foreTop = thumb;
            sb.progressPos = trackPos
            var step = 1 //..math.floor( (max + rc.height()) / sb.foreTop );//绝对高度的时候计算步进
            sb.show(overstep > 0);
            sb.onPosChanged = function( pos,thumbTrack ){
                if(thumbTrack){	
                    trackPos = overstep - pos;
                    //..io.print(trackPos)
                    ::SendMessageInt(this.hwnd, 0x115/*_WM_VSCROLL*/,::MAKELONG(4/*_SB_THUMBPOSITION*/,trackPos), 0);
                }	
            }
               this.wndproc = function(hwnd,message,wParam,lParam){
                    select(message) {
                        case 0x20A/*_WM_MOUSEWHEEL*/ {
                        if( ::HIWORD(wParam) & 0x8000){ 
                            if(sb.stepProgress(-step)){::SendMessageInt(this.hwnd, 0x115/*_WM_VSCROLL*/, 1/*_SB_LINEDOWN*/, 0);} 
                        }else { 
                            ::SendMessageInt(this.hwnd, 0x115/*_WM_VSCROLL*/,  0/*_SB_LINEUP*/, 0);
                               sb.stepProgress(step);
                            }
                        return 0;		
                        }case 0x115/*_WM_VSCROLL*/{
                            //..io.print(::HIWORD(wParam),::LOWORD(wParam))		
                        }case 0x200/*_WM_MOUSEMOVE*/{
                            if(wParam & 1/*_MK_LBUTTON*/){
                                var x,y = ..win.getMessagePos(lParam);
                              var topIndex = ::SendMessageInt(this.hwnd,0x18E/*_LB_GETTOPINDEX*/,0,0);
                              /*获取列表框中第一个可见项的索引。最初，索引 0 的项位于列表框的顶部，
                              但如果列表框内容已滚动，则另一项可能位于顶部。多列列表框中的第一个可见项是左上角项。*/
                              trackPos = overstep - topIndex;
                              sb.progressPos = trackPos;
                            }
                        }case 0x181/*_LB_INSERTSTRING*/{//LB_ADDFILE、LB_ADDSTRING没有尝试，不知道要不要一起处理。 
                            max = (this.count + 1) * itemHeight; //显示区域高度,在_LB_INSERTSTRING事件中，添加表项在事件之前发生实际表项数目要 + 1
                           overstep = (max - rc.height()) / itemHeight//溢出表项计数	
                           thumb = ..math.floor(rc.height() / max * sb.height);	
                           var topIndex = ::SendMessageInt(this.hwnd,0x18E/*_LB_GETTOPINDEX*/,0,0);
                           trackPos = 	overstep - topIndex;
                        sb.setTrackbarRange(0,overstep);
                        sb.foreTop = thumb;
                        sb.progressPos = trackPos;
                        sb.show(overstep > 0);
                        }case 0x182/*_LB_DELETESTRING*/{
                        max = (this.count - 1) * itemHeight; //显示区域高度,在_LB_DELETESTRING事件中，删除表项在事件之后发生，实际表项数目要 - 1
                           overstep = (max - rc.height()) / itemHeight//溢出表项计数	
                           thumb = ..math.floor(rc.height() / max * sb.height);	
                           trackPos = overstep;
                        sb.setTrackbarRange(0,overstep);
                        sb.foreTop = thumb;
                        sb.progressPos = trackPos;
                        sb.show(overstep > 0);
                        }case 0x184/*_LB_RESETCONTENT*/{
                            sb.show(false);	
                        }	
                    } 	
              }
        };
    
    }
    namespace scrollbarEx{  
        style = {
            background={
                default=0xFFE1E1E1; 
            };
            color={
                default	= 0xffc4c4c4;
                hover 	= 0xFF999999;
                active	= 0xFF999999;
            }
       } 
    }
    
    io.open()
    for(i=1;50;1){
        winform.listbox.add("这是测试项目--" ++ i )
    
    }
    
    
    winform.button.oncommand = function(id,event){
        for(i=51;100;1){
            winform.listbox.add("这是测试项目--" ++ i )
        }
    }
    
    winform.button2.oncommand = function(id,event){
        winform.listbox.clear()
    }
    
    winform.button3.oncommand = function(id,event){
        
        winform.listbox.delete(math.random(1,winform.listbox.count))
        
    }
    
    scrollbarEx(winform.listbox)
    
    winform.show();
    win.loopMessage();