我正在尝试通过这个站点学习 AJAX。我已经将它归结为“您必须将代码放入 onModuleLoad()”部分（在清单 4 的正上方）。我在我的 Eclipse 项目中发现了两个提到 onModuleLoad() 的区域：slicr.java 和 gwt-user.jar/com.google.gwt.core.client 包中的实际 EntryPoint.class 文件。当我尝试将列表的内容添加到 slicr.java 时，我得到大量无法解析为类型错误，并且我无法向 EntryPoint.class 添加任何内容，因为它似乎已被锁定，无法编辑。我真的很感谢有人可以给我的任何帮助！
这是我添加到 slicr.java 后的代码：
package com.ibm.examples.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.Widget;
/**
* Entry point classes define <code>onModuleLoad()</code>.
*/
public class Slicr implements EntryPoint {
private DockPanel panel;
private List clearables;
/**
* This is the entry point method.
*/
public void onModuleLoad() {
clearables = new ArrayList();
initDockPanel();
panel.add(buildActionPanel(), DockPanel.SOUTH);
panel.add(buildPizzaTypePanel(), DockPanel.WEST);
panel.add(buildToppingPanel(), DockPanel.EAST);
RootPanel.get("slicr").add(panel);
}
private void initDockPanel() {
panel = new DockPanel();
panel.setBorderWidth(1);
panel.setSpacing(5);
}
public HorizontalPanel buildActionPanel() {
HorizontalPanel actions = new HorizontalPanel();
actions.setSpacing(10);
Button clear = new Button("Clear");
clear.addClickListener(new ClearClickListener());
Button newPizza = new Button("Another Pizza");
Button submitOrder = new Button("Submit");
actions.add(clear);
actions.add(newPizza);
actions.add(submitOrder);
return actions;
}
public static final String[] PIZZA_TYPES = new String[] {
"Thin Crust Medium", "Thin Crust Large",
"Thin Crust X-Large", "Thick Crust Medium",
"Thick Crust Large"
};
private VerticalPanel buildPizzaTypePanel() {
VerticalPanel pizzaTypes = new VerticalPanel();
HTML label = new HTML("<h2>Pizza</h2>");
pizzaTypes.add(label);
for (int i = 0; i < PIZZA_TYPES.length; i++) {
RadioButton radio = new RadioButton("pizzaGroup",
PIZZA_TYPES[i]);
clearables.add(radio);
pizzaTypes.add(radio);
}
return pizzaTypes;
}
public static final String[] TOPPINGS = new String[] {
"Anchovy", "Gardineria", "Garlic",
"Green Pepper", "Mushrooms", "Olives",
"Onions", "Pepperoni", "Pineapple",
"Sausage", "Spinach"
};
private VerticalPanel buildToppingPanel() {
VerticalPanel toppings = new VerticalPanel();
toppings.add(new HTML("<h2>Toppings</h2>"));
Grid topGrid = new Grid(TOPPINGS.length + 1, 3);
topGrid.setText(0, 0, "Topping");
topGrid.setText(0, 1, "Left");
topGrid.setText(0, 2, "Right");
for (int i = 0; i < TOPPINGS.length; i++) {
Button button = new Button(TOPPINGS[i]);
CheckBox leftCheckBox = new CheckBox();
CheckBox rightCheckBox = new CheckBox();
clearables.add(leftCheckBox);
clearables.add(rightCheckBox);
button.addClickListener(new ToppingButtonListener(
leftCheckBox, rightCheckBox));
topGrid.setWidget(i + 1, 0, button);
topGrid.setWidget(i + 1, 1, leftCheckBox);
topGrid.setWidget(i + 1, 2, rightCheckBox);
}
toppings.add(topGrid);
return toppings;
}
private class ClearClickListener implements ClickListener {
public void onClick(Widget sender) {
for (Iterator iter = clearables.iterator(); iter.hasNext();) {
CheckBox cb = (CheckBox) iter.next();
cb.setChecked(false);
}
}
}
private class ToppingButtonListener implements ClickListener {
private CheckBox cb1;
private CheckBox cb2;
public ToppingButtonListener(CheckBox cb1, CheckBox cb2) {
this.cb1 = cb1;
this.cb2 = cb2;
}
public void onClick(Widget sender) {
boolean unchecked = !cb1.isChecked() && !cb2.isChecked();
cb1.setChecked(unchecked);
cb2.setChecked(unchecked);
}
}
这是EntryPoint.class：
/*
* Copyright 2006 Google Inc.
*/
package com.google.gwt.core.client;
/**
* Implement this interface to allow a class to act as a module entry point.
* Please see the developer guide for more information on modules.
*/
public interface EntryPoint {
/**
* The entry point method, called automatically by loading a module that
* declares an implementing class as an entry-point.
*/
void onModuleLoad();
}