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Java 将模型类添加到泛型列表会引发错误_Java_Android_Generics - Fatal编程技术网

Java 将模型类添加到泛型列表会引发错误

Java 将模型类添加到泛型列表会引发错误,java,android,generics,Java,Android,Generics,我是Android开发新手,在这里无法解决这个问题。我创建了一个名为video的空白类,它有两个属性name和url: public class Video { public String _name; public String _Url; public Video(String name, String Url) { _name = name; _Url = Url; } public String getNa

我是Android开发新手,在这里无法解决这个问题。我创建了一个名为video的空白类,它有两个属性name和url:

public class Video {
    public String _name;
    public String _Url;

    public Video(String name, String Url)
    {
        _name = name;
        _Url = Url;
    }
    public String getName()
    {
       return _name;
    }
    public String getUrl()
    {
       return _Url;
    }

}
然后,我有一个用于将视频添加到的常规列表。在活动调用VideosListActivity中,将视频添加到列表时会引发错误:

public List<Video> ListResult;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //Update view

        setContentView(R.layout.videos);

        setTitle("VIDEOS");

        //--videos created here
        Video NewVideo = new Video("video one","http://www.youtube.com/watch?v=cxLG2wtE7TM");

        ListResult.add(NewVideo);

        Log.v("VideoList", "Opened list");

在向列表中添加元素之前,您需要初始化列表结果,如下所示:

public List<Video> ListResult;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //Update view

        setContentView(R.layout.videos);

        ListResult= new ArrayList<Video>();  //<< initialize List here
公共列表列表结果;
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
//更新视图
setContentView(R.layout.videos);

ListResult=new ArrayList();//理想情况下,将字段设置为私有字段并遵守Java命名约定,当然。。。
public List<Video> ListResult;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //Update view

        setContentView(R.layout.videos);

        ListResult= new ArrayList<Video>();  //<< initialize List here