Codeausschnitt zum Implementieren des Verschiebens und Ziehens von Bildern auf Webseiten

以下这段JS是主要解决在画面生成Image项目,并通过鼠标事件进行脱拽、移动等操作的代码.
<script language="javascript" type="text/javascript">
var oben, links;
var src,drag,dir,ope,refer,halfwidth;
var-Einheit=30;

var aryItems,itemNum=10,index,isInit,id,max=23;

Funktion PageLoad()
{
document.form1.onsubmit=OnSubmit;

aryItems=new Array(itemNum);
top=document.getElementById("TABLE").getClientRects()[0].top;
left=document.getElementById("TABLE").getClientRects()[0].left;

if(document.getElementById("__Gantt").value!=null&&document.getElementById("__Gantt").value!="")
{
var gantt=document.getElementById("__Gantt").value;
var array=gantt.split(";");
var length=array.length-1;
var start,width,item;

for(index=0;index<länge;index++)
{
item=array[index].split(",");
start=item[0];
width=item[1];

id="Item"+index;
aryItems[index]=id;

var track = document.createElement("IMG");
track.setAttribute("id",id);
track.setAttribute("src","blue.gif");

document.body.appendChild(track);
document.getElementById(id).style.position="absolute";
document.getElementById(id).style.top=top+unit*index;
document.getElementById(id).style.left=left+unit*start;
document.getElementById(id).width=unit*width;
document.getElementById(id).style.zIndex=9;
}
}
anders
{
for(index=0;index<itemNum;index++)
{
id="Item"+index;
aryItems[index]=id;

var track = document.createElement("IMG");
track.setAttribute("id",id);
track.setAttribute("src","blue.gif");

document.body.appendChild(track);
document.getElementById(id).style.position="absolute";
document.getElementById(id).style.top=top+unit*index;
document.getElementById(id).style.left=left+unit*index;
document.getElementById(id).width=unit;
document.getElementById(id).style.zIndex=9;
}
}
ziehen=false;
left=document.getElementById(aryItems[0]).getClientRects()[0].left;
}

Funktion OnDrag()
{
if(event.srcElement.tagName!="IMG"&&!drag)
{
if(event.srcElement.id=="btnTrim")
{
// OnTrim();
}
}
anders
{
if(!ziehen)
{
src=event.srcElement;
halfwidth=src.width/2;
ziehen=true;

// 方向の判断
if(event.clientX<src.getClientRects()[0].left+halfwidth)
{
dir="Rückwärts";
refer=src.getClientRects()[0].left+src.width;
}
anders
{
dir="Vorwärts";
refer=src.getClientRects()[0].left;
}

// 操作の判断：１．移動・２．縮小／拡大
if(event.shiftLeft)
{
ope="Verschieben";
refer=event.clientX-src.getClientRects()[0].left;
}
anders
{
ope="Skala";
}
}
anders
{
if(ope=="Skala")
{
var sleft=Math.ceil((src.getClientRects()[0].left-left)/unit-1)*unit+left;
var header=src.getClientRects()[0].left-src.getClientRects()[0].left;
var tail=src.width-header-Math.ceil((src.width-header)/unit)*unit;
var swidth=Math.ceil((src.width-header)/unit)*unit;
if(header>0)
{
swidth=Breite+Einheit;
}
if(tail>0)
{
swidth=Breite+Einheit;
}
src.style.left=sleft;
src.width=swidth;
}

if(ope=="Verschieben")
{
src.style.left=Math.ceil((src.getClientRects()[0].left-left)/unit-1)*unit+left;
}

ziehen=false;
OnTrim()
}
}
}

Funktion OnScale()
{
if(src!=null&&drag)
{
if(ope=="Skala")
{
// 縮小／拡大の場合
if(dir=="Weiterleiten")
{
if(event.clientX-refer>=unit)
{
src.width=event.clientX-refer;
}
}
anders
{
if(refer-event.clientX>unit)
{
src.style.left=event.clientX;
src.width=refer-src.getClientRects()[0].left;
}
}
}
anders
{
// 移動の場合http://www.devdao.com/
src.style.left=event.clientX-refer;
}
}

if(event.srcElement!=null)
{
if(event.srcElement.tagName=="IMG")
{
if(event.clientX<event.srcElement.getClientRects()[0].left+unit/2)
{
event.srcElement.style.cursor="w-resize";
}
anders
{
event.srcElement.style.cursor="e-resize";
}
}
}
}

Funktion OnTrim()
{
var pre,post;
for(index=0;index<itemNum-1;index++)
{
pre=document.getElementById(aryItems[index]);
post=document.getElementById(aryItems[index+1]);
if(pre.getClientRects()[0].left+pre.width!=post.getClientRects()[0].left)
{
post.style.left=pre.getClientRects()[0].left+pre.width-2;
}
}

for(index=0;index<itemNum;index++)
{
pre=document.getElementById(aryItems[index]);
if(pre.getClientRects()[0].left>=left+unit*max)
{
pre.style.left=left+unit*max-2;
pre.width=unit;
}

if((pre.getClientRects()[0].left<left+unit*max)&&(pre.getClientRects()[0].left+pre.width>left+unit*max))
{
pre.width=left+unit*max-pre.getClientRects()[0].left;
}
}
}

Funktion OnSubmit()
{
var t="";
for(index=0;index<itemNum;index++)
{
t=t+((document.getElementById(aryItems[index]).getClientRects()[0].left-left)/unit).toString();
t=t+",";
t=t+(document.getElementById(aryItems[index]).width/unit).toString();
t=t+";";
}
document.getElementById("__Gantt").value=t;
}

document.onmousedown=OnDrag;
document.onmousemove=OnScale;
</script>
当有一个Button做表单提交的时候, 会先执行OnSubmit代码段来的东西原封不动地发挥去, 其中可以加入对数据的修改过程, 也可以是通过一进入页面就倒入数据而达到生成画面的目的.
Protected Sub Button1_Click()Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Behandelt Button1.Click
Response.Write(Request.Params.Item("__Gantt") & "<BR>")
Dim strGantt As String = Request.Params.Item("__Gantt")
ClientScript.RegisterHiddenField("__Gantt", strGantt)

End Sub

Protected Sub Page_Load()Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Behandelt Me.Load
Wenn nicht, dann IsPostBack
ClientScript.RegisterHiddenField("__Gantt", String.Empty)
Ende wenn
„End Sub“ wird nicht angezeigt.