Difference Between this.getView().byId(), this.byId(), and sap.ui.getCore().byId()

问题

Can I know the difference and performance when I use

var myControl = this.getView().byId("myIDhere");
var myControl = this.byId("myIDhere");
var myControl = sap.ui.getCore().byId("myIDhere");

Which of three is best to use to perform operations on control when I use XML views in UI5 apps?

回答1:

• this.getView().byId(...) is equivalent to this.byId(...). Take a look at the source code to see what byId does:

  // sap.ui.core.mvc.Controller
  Controller.prototype.byId = function(sId) {
    return this.oView ? this.oView.byId(sId) : undefined;
  };
  

  As you can see, this.byId is just a shortcut for this.getView().byId. They both can be used to access controls defined in the view. E.g.:

  this.byId("myPanel");
  

• sap.ui.getCore().byId(...)API, on the other hand, awaits a fully concatenated global ID which is why you cannot simply exchange this.byId with sap.ui.getCore().byId if the target control is a view descendant.

  sap.ui.getCore().byId("__xmlview0--myPanel"); // <-- Please don't do that!
  

More about IDs:

• Stable IDs: All You Need to Know
• For the sake of completeness: How to Access Elements from XML Fragment by ID

来源：https://stackoverflow.com/questions/48639302/difference-between-this-getview-byid-this-byid-and-sap-ui-getcore-byid