错误 No enclosing instance of type WallpaperService is available due to some intermediate constructor invocation
引用:http://blog.csdn.net/You_and_Me12/article/details/7173825
No enclosing instance of type WallpaperService is available due to some intermediate constructor invocation
错误代码:
- import android.app.Service;
- import android.os.Bundle;
- import android.service.wallpaper.WallpaperService;
- import android.service.wallpaper.WallpaperService.Engine;
- import android.view.MotionEvent;
- import android.view.SurfaceHolder;
- public class MyEngine extends Engine{
- ……
才发现是继承了内隐类了,查找了一下
参考引文如下:点击打开链接
- 这是在《JAVA编程思想》上看到的一道例题,是关于继承inner classes(内隐类)的。
- 先把代码和书上的一些原话写出来,如下:
- 由于inner class的构造函数必须连接到一个reference指向outer class 对象身上,所以
- 当你继承inner class时,事情便稍微复杂些。问题出在“指向outer class对象”的那个
- 神秘reference必须被初始化。但derived class之内不存在可连接的缺省对象,这个问题
- 的答案是,使用专用语法,明确产生该关联性:
- class WithInner {
- class Inner{}
- }
- public class InheritInner extends WithInner.Inner {
- InheritInner(WithInner wi) {
- wi.super(); //---这里不懂,wi.super()指的是什么,有什么用?
- }
- public static void main(String[] args) {
- WithInner wi = new WithInner();
- InheritInner ii = new InheritInner(wi);
- }
- }
正确修改后为:
- import android.app.Service;
- import android.os.Bundle;
- import android.service.wallpaper.WallpaperService;
- import android.service.wallpaper.WallpaperService.Engine;
- import android.view.MotionEvent;
- import android.view.SurfaceHolder;
- public class MyEngine extends Engine{
- public MyEngine(WallpaperService wp) {//添加的
- wp.super();
- }
- ……