我编写了一个jQuery插件，每0.5秒检查一次工具栏是否有请求的元素。

(function( $ ) {
/**
 * Wait until element has finish loading requested elements, then execute callback 
 * @param string element Element to wait for
 * @param object callback Callback to execute
 * @param integer timeout Optional timeout to stop testing the element if none of the requested element was found
 */
$.fn.waitEdToolbarLoaded = function( element, callback, timeout ) {

    var interval = null;
    var target = this;
    var timeout = typeof timeout !== \'undefined\' ? timeout : 5000;

    interval = window.setInterval(

        function () {

            var length = $( target ).find( element ).length;
            timeout -= 500;

            if( 0 > timeout  ) {
                window.clearInterval( interval );
            }

            if( 0 < length ) {
                window.clearInterval( interval );
                callback();
            }
        },
        500
    );

}
})( jQuery );

jQuery( document ).ready(
function( $ ) {

    // callback to execute if the requested element was found
    function alarm() { alert( \'Toolbar ready!\' ); }

    // wait for elements
    $( \'#edtoolbar\' ).waitEdToolbarLoaded( \'p\', alarm );

    // create the elements after 3 seconds
    setTimeout(
        function () {
            for ( var i=1; i<4; i++ ) { $( \'#edtoolbar\' ).append( \'<p>\'+i+\'</p>\' ); }
        },
        3000
    );

}
);