我正在尝试使用 littemplate 从客户端调用服务器端函数。我检查了 Vaadin 站点上的示例,发现客户端可以通过 this.$server._some_method 调用服务器端。我尝试在 littemplate 中使用 $server,但在前端编译期间,vaadin 抛出错误,指出“属性 '$server' 在类型 'HelloWorld' 上不存在”。请让我知道这个程序有什么问题并指导我。谢谢你。
光照模板
import {LitElement, html} from 'lit-element';
import '@vaadin/vaadin-button/vaadin-button.js';
class HelloWorld extends LitElement {
render() {
return html`
<div>
<vaadin-button id="helloButton">Click me!</vaadin-button>
</div>`;
}
sayHello(){
showNotification("Hello");
this.$server.greet(); //Problematic statement.
}
}
customElements.define('hello-world', HelloWorld);
爪哇
package com.example.application.littemplate;
import com.vaadin.flow.component.Tag;
import com.vaadin.flow.component.button.Button;
import com.vaadin.flow.component.dependency.JsModule;
import com.vaadin.flow.component.littemplate.LitTemplate;
import com.vaadin.flow.component.notification.Notification;
import com.vaadin.flow.component.template.Id;
import com.vaadin.flow.component.textfield.TextField;
//HelloWorld.java
@Tag("hello-world")
@JsModule("./views/littemplate/hello-world.ts")
public class HelloWorld extends LitTemplate {
@Id
// Uses the vaadin-button id "helloButton"
private Button helloButton;
public HelloWorld() {
helloButton.addClickListener(event -> Notification.show("Hello " + nameField.getValue()));
}
@ClientCallable
public void greet() {
System.out.println("Hello server");
}
}