在新开发的基于J2ee的应用系统中，客户端页面输出数据用表格是在也普通不过的事了！排序的问题已经解决了，由于原来项目采用的是pb开发的，大家习惯了数据窗口的功能，提出了新的需求，为方便浏览数据，数据列是否可以随意拖动顺序由用户自动排列！
的确，这个问题相对比较困难，我本人从来没有见过这种程序。经过仔细思考，这种情况不能在服务器端处理，用户排列规则无法保存也是不断变化的。于是决定在客户端采用javascript进行处理，这样速度也快！
上网好不容易找到了一篇文章，采用的cell的swapnode方法对列进行交换，然而经过测试发觉表格前好像不能有别的页面元素，否则不能正确排序。后来在csdn上找到一篇文章是在。net下扩展客户端功能的，细想客户端不是也用javascript控制的吗，于是拿过来分析一下，经过稍微修改后，成功实现所需功能。在此向原作者表示感谢，同与大家共享，希望对大家有所帮助。至于原文大家在csdn搜索可得到。
源码如下：
var tbody, headRow;
var bDragMode = false;
var objDragItem;
var arrHitTest = new Array();
var iArrayHit = false;
var ColumnCount = null;
var mustRefresh = false;
var dragColor=null;
var hitColor=null;
var HasTopMostPager=null;
var PowerTable=null;
//
// Init function.. Fills out variables with data
// loaded with oncontentready.
//将table初始化
function initDragTable(table)
{
var i;
PowerTable=table;
if (dragColor == null)
dragColor = "white";
if (hitColor == null)
hitColor = "lightblue";
// get TBODY - take the first TBODY for the table
tbody = PowerTable.tBodies(0);
if (!tbody) return;
// get THEAD - take the unique THEAD for the table
var click = PowerTable.tHead;
if (!click) return;
// Determine the row to use (read from HasPager)
if (HasTopMostPager == "true")
headRow = click.children[1];
else
headRow = click.children[0];
if (headRow.tagName != "TR") return;
headRow.runtimeStyle.cursor = "hand"; //"move";
ColumnCount = headRow.children.length;
for(i=0; i < ColumnCount ; i++)
{
arrHitTest[i] = new Array();
}
var cx=0;
var cy=0;
var c;
defaultTitleColor = headRow.children[0].currentStyle.backgroundColor;
for (i=0; i<ColumnCount ; i++) {
var clickCell = headRow.children[i];
clickCell.selectIndex = i;
c = clickCell.offsetParent;
if (cx == 0 && cy == 0)
{
while (c.offsetParent != null) {
cy += c.offsetTop;
cx += c.offsetLeft;
c = c.offsetParent;
}
}
arrHitTest[i][0] = cx + clickCell.offsetLeft;
arrHitTest[i][1] = cy + clickCell.offsetTop;
arrHitTest[i][2] = clickCell;
arrHitTest[i][3] = cx + clickCell.offsetLeft + clickCell.clientWidth;
clickCell.attachEvent("onmousedown",onMouseDown);
}
PowerTable.attachEvent("onmousemove",onMouseMove);
PowerTable.attachEvent("onmouseup",onMouseUp);
///////
if (arrHitTest[0][0] == arrHitTest[0][3])
mustRefresh = true;
}
function InitHeader()
{
var cx=0;
var cy=0;
var c;
for (i=0; i<ColumnCount ; i++) {
var clickCell = headRow.children[i];
clickCell.selectIndex = i;
c = clickCell.offsetParent;
if(cx == 0 && cy == 0 )
{
while (c.offsetParent != null) {
cy += c.offsetTop;
cx += c.offsetLeft;
c = c.offsetParent;
}
}
arrHitTest[i][0] = cx + clickCell.offsetLeft;
arrHitTest[i][1] = cy + clickCell.offsetTop;
arrHitTest[i][2] = clickCell;
arrHitTest[i][3] = cx + clickCell.offsetLeft + clickCell.clientWidth;
}
}
function ChangeHeader(iChange)
{
for(var y = 0; y < arrHitTest.length; y++)
{
if (arrHitTest[y][2].currentStyle.backgroundColor == hitColor)
arrHitTest[y][2].style.backgroundColor = defaultTitleColor;
}
if(iChange == "-1") return;
arrHitTest[iChange][2].style.backgroundColor = hitColor;
}
function onMouseUp(e)
{
if(!bDragMode) return;
bDragMode = false;
var iSelected = objDragItem.selectIndex;
objDragItem.removeNode(true);
objDragItem = null;
ChangeHeader(-1);
if( (iArrayHit - 1) < 0 || iSelected < 0) return; // default faliure
// iSelected is the 0-based index of the column being moved
// (iArrayHit-1) is the 0-based index of the column being replaced
CopyRow(iSelected, (iArrayHit - 1) );
// Reset our variables
iSelected = 0;
iArrayHit = -1;
}
function onMouseDown(e)
{
// If the grid is contained in an invisible panel (other DHTML stuff)
// the initialization step must be repeated to take real values
if( mustRefresh) {
InitHeader();
mustRefresh = false;
}
bDragMode = true;
var src = e.srcElement;
var c = e.srcElement;
while (src.tagName != "TD")
src = src.parentElement;
// Create our header on the fly
objDragItem = document.createElement("DIV");
objDragItem.innerHTML = src.innerHTML;
objDragItem.style.height = src.offsetParent.clientHeight;
objDragItem.style.width = src.clientWidth;
objDragItem.style.background = dragColor;
objDragItem.style.fontColor = src.currentStyle.fontColor;
objDragItem.style.position = "absolute";
objDragItem.style.filter = "progid:DXImageTransform.Microsoft.Alpha(opacity=75)";
objDragItem.selectIndex = src.selectIndex;
objDragItem.style.border = "1 solid black";
while (c.offsetParent != null)
{
objDragItem.style.y += c.offsetTop;
objDragItem.style.x += c.offsetLeft;
c = c.offsetParent;
}
objDragItem.style.borderStyle = "dashed";
objDragItem.style.borderWidth = "1px";
objDragItem.style.display = "none";
src.insertBefore(objDragItem);
}
function onMouseMove(e)
{
if(!bDragMode || !objDragItem) return;
// If we aren't dragging or our object is null, we return
// Hardcoded value for height difference
var midWObj = objDragItem.style.posWidth / 2;
var midHObj = 12;
// Save mouse's position in the document
var intTop = e.clientY +document.body.scrollTop;
var intLeft = e.clientX + document.body.scrollLeft;
var cx=0,cy=0;
var elCurrent = objDragItem.offsetParent;
if (elCurrent != null)
{
while (elCurrent.offsetParent != null) {
cx += elCurrent.offsetTop;
cy += elCurrent.offsetLeft;
elCurrent = elCurrent.offsetParent;
}
}
objDragItem.style.pixelTop = intTop - cx - midHObj;
objDragItem.style.pixelLeft = intLeft - cy - midWObj;
if(objDragItem.style.display == "none")
objDragItem.style.display = "";
iArrayHit = CheckHit(intTop , intLeft , e);
e.cancelBubble = false;
e.returnValue = false;
}
function CheckHit(x,y,e)
{
midWObj = objDragItem.style.posWidth / 2;
midHObj = 12;
for(var i=0; i < ColumnCount; i++)
{
if( (y) > (arrHitTest[i][0]) && (y) < (arrHitTest[i][3] ))
{
ChangeHeader(i);
return i + 1;
}
}
return -1;
}
//
// Copy from row to row.. Does the Header also.
//
function CopyRow(from, to)
{
if(from == to) return;
var origfrom = from;
var origto = to;
var iDiff = 0;
if( from > to )
{
iDiff = from - to;
var saveObj = headRow.children[from].innerHTML;
var saveWidth = headRow.children[from].width;
for(var i = 0 ; i < iDiff; i++)
{
headRow.children[from].innerHTML = headRow.children[from - 1].innerHTML;
headRow.children[from].width = headRow.children[from - 1].width;
from--;
}
headRow.children[to].innerHTML = saveObj;
headRow.children[to].width = saveWidth;
}
else
{
iDiff = to - from;
var saveObj = headRow.children[from].innerHTML;
var saveWidth = headRow.children[from].width;
for(var i = 0 ; i < iDiff; i++)
{
headRow.children[from].innerHTML = headRow.children[from + 1].innerHTML;
headRow.children[from].width = headRow.children[from + 1].width;
from++;
}
headRow.children[to].innerHTML = saveObj;
headRow.children[to].width = saveWidth;
}
for(var i = 0 ; i < headRow.children.length; i++)
headRow.children[i].selectIndex = i;
InitHeader();
for ( var iRowInsert = 0 ; iRowInsert < tbody.rows.length; iRowInsert++ )
{
from = origfrom;
to = origto;
if( from > to )
{
iDiff = from - to;
var saveObj;
try {
saveObj = tbody.children[iRowInsert].children[from].innerHTML;
} catch(e) { saveObj = null; }
for(var i = 0 ; i < iDiff; i++)
{
try {
tbody.children[iRowInsert].children[from].innerHTML = tbody.children
[iRowInsert].children[from - 1].innerHTML;
from--;
} catch(e) {}
}
if (saveObj != null)
tbody.children[iRowInsert].children[to].innerHTML = saveObj;
}
else
{
iDiff = to - from;
var saveObj;
try {
saveObj = tbody.children[iRowInsert].children[from].innerHTML;
} catch(e) {}
for(var i = 0 ; i < iDiff; i++)
{
try {
tbody.children[iRowInsert].children[from].innerHTML = tbody.children
[iRowInsert].children[from + 1].innerHTML;
from++;
} catch(e) {}
}
try {
tbody.children[iRowInsert].children[to].innerHTML = saveObj;
} catch(e) {}
}
}
////////
var buf = "";
for(var i=0; i<headRow.children.length; i++)
{
var td = headRow.children[i];
tmp = td.innerHTML;
pos = tmp.indexOf("<");
if (pos > 0)
tmp = tmp.substring(0, pos);
else
{
if (pos == 0)
tmp = td.innerText;
}
buf += tmp;
if (i < headRow.children.length-1)
buf += ",";
}}
另外你的表格必须由thead、tbody组成。
