someObject。$（）含义

Question

someObject.$()是什么意思？

我正在浏览sapui5工具包中的tilecontainer-dbg文件并发现：

var oDomRef = this.$();
or someObject.$()

Answer 1

$只是javascript中的合法符号。因此，this.$()或someObject.$()只是对该对象的方法调用。该对象有一个名为$的属性，它是一个函数（例如方法）。

这是一个例子：

var obj = {
    "data": 3,
    "$": function() {
         return this.data;
    }
};

var val = obj.$();          // returns 3

Answer 2

在SAPUI5中，$＆amp; jQuery是用于访问jQuery功能的全局变量

this.$() is similar to jQuery('#this.sId')
or
document.getElementById(this.sId)

返回表示此Element包装为jQuery对象的最合适的DOM节点。

下面是代码定义

/**
* Returns the best suitable DOM node that represents this Element wrapped as jQuery object.
* I.e. the element returned by {@link sap.ui.core.Element#getDomRef} is wrapped and returned.
*
* If an ID suffix is given, the ID of this Element is concatenated with the suffix 
* (separated by a single dash) and the DOM node with that compound ID will be wrapped by jQuery.
* This matches the UI5 naming convention for named inner DOM nodes of a control. 
* 
* @param {string} [sSuffix] ID suffix to get a jQuery object for
* @return {jQuery} The jQuery wrapped element's DOM reference
* @protected
*/

sap.ui.core.Element.prototype.$ = function(sSuffix) {
  return jQuery(this.getDomRef(sSuffix));
 };