Question

我想在点击不同的按钮时调用不同的方法（在单个GWT事件处理程序类中）？就像这样：

假设我的UI中有3个按钮：

Button1的
将Button2
将Button3

而且，我为每个人添加了相同的（Click）EventHandler：ButtonClicker

在OnClick（）方法中，我想调用与单击的按钮对应的方法。这里有一些示例代码，可以更好地说明我要做的事情：

public class ButtonClicker implements ClickHandler 
{
    public void onClick(ClickEvent event)
    {
        PushButton clickedButton = (PushButton) event.getSource();

        // I could call the corresponding method using if-else condition but I do not want to do that. 
        // Instead, I want some code here, may be using JSNI (using eval in some way) or something like that to call the corresponding method.
        ......      
    }

    private void Button1Click()
    {
        // Code to handle Button1 Click 
    }

    private void Button2Click()
    {
        // Code to handle Button2 Click
    }

    private void Button3Click()
    {
        // Code to handle Button3 Click
    }
}

提前致谢。

Answer 1

我认为你有充分的理由去这条错综复杂的路线，所以这是一个提案，不包含任何判断：

JavaScriptObject map = createMap(this);

private static native JavaScriptObject createMap(ButtonClicker o) /*-{
   // Note: does not use $entry() as this will be called from GWT code
   return {
       "button1": function() { o.@foo.ButtonClicker::Button1Click()(); },
       "button2": function() { o.@foo.ButtonClicker::Button2Click()(); },
       "button3": function() { o.@foo.ButtonClicker::Button3Click()(); }
     };
}-*/;

private static native void call(JavaScriptObject map, String id) /*-{
  var fn = map[id];
  // TODO: add null-check / fallback behavior
  fn();
}-*/;

@Override
public void onClick(ClickEvent event) {
  call(map, ((UIObject) event.getSource()).getElement().getId());
}

如何在GWT中调用单个eventhandler类中编写的相应Java方法（对于每个按钮）？

1 个答案: