easyui datagrid 右键 仿ext

var createGridHeaderContextMenu = function(e, field) {
    e.preventDefault();
    var grid = $(this);/* grid本身 */
    var headerContextMenu = this.headerContextMenu;/* grid上的列头菜单对象 */
    if (!headerContextMenu) {
        var tmenu = $('<div style="100px;"></div>').appendTo('body');
        var asc = $('<div iconCls="icon-asc" field="asc">升序</div>').appendTo(tmenu);
        var desc = $('<div iconCls="icon-desc" field="desc">降序</div>').appendTo(tmenu);
        var filedHTML = $('<div iconCls="icon-columns"></div>');
        var span = $('<span>显示列/隐藏列</span>');
        var spdiv = $('<div></div>');
        var fields = grid.datagrid('getColumnFields');
        for ( var i = 0; i < fields.length; i++) {
            var fildOption = grid.datagrid('getColumnOption', fields[i]);
            if (!fildOption.hidden) {
                $('<div iconCls="icon-checked" field="' + fields[i] + '"/>').html(fildOption.title).appendTo(spdiv);
            } else {
                $('<div iconCls="icon-unchecked" field="' + fields[i] + '"/>').html(fildOption.title).appendTo(spdiv);
            }
        }
        span.appendTo(filedHTML);
        spdiv.appendTo(filedHTML);
        filedHTML.appendTo(tmenu);
        headerContextMenu = this.headerContextMenu = tmenu.menu({
            onClick : function(item) {
                var f = $(this).attr('field')
                var fieldProperty = $(item.target).attr('field');
                if (item.iconCls == 'icon-checked') {
                    grid.datagrid('hideColumn', fieldProperty);
                    $(this).menu('setIcon', {
                        target : item.target,
                        iconCls : 'icon-unchecked'
                    });
                }
                if (item.iconCls == 'icon-unchecked') {
                    grid.datagrid('showColumn', fieldProperty);
                    $(this).menu('setIcon', {
                        target : item.target,
                        iconCls : 'icon-checked'
                    });
                }
                if (item.iconCls == 'icon-asc') {
                    var options = grid.datagrid('options');
                    options.sortName = f;
                    options.sortOrder =fieldProperty;
                    grid.datagrid('reload');
                }
                if (item.iconCls == 'icon-desc') {
                    var options = grid.datagrid('options');
                    options.sortName = f;
                    options.sortOrder =fieldProperty;
                    grid.datagrid('reload');
                }
            }
        });
    }
    headerContextMenu.attr('field',field);
    headerContextMenu.menu('show', {
        left : e.pageX,
        top : e.pageY
    });
};
$.fn.datagrid.defaults.onHeaderContextMenu = createGridHeaderContextMenu;
$.fn.treegrid.defaults.onHeaderContextMenu = createGridHeaderContextMenu;