无法从类型Cmd对非静态方法getVideoURL（）进行静态引用

Question

I'm getting an error stating:

"Cannot make a static reference to the non-static method getVideoURL() from the type Cmd CustomListViewAdapter " on the line: String txt=Cmd.getVideoURL();

The issue is being cause by this line:

  public  String getVideoURL() {
        return videourl;
    }

in Cmd.java

I've tried setting the strings to Static - but it prevents my data from being updated.

How might this situation be avoided?

Source:CustomListViewAdapter.java

public class CustomListViewAdapter extends ArrayAdapter<Cmd> {
Activity context;
List<Cmd> videos;

public CustomListViewAdapter(Activity context, List<Cmd> videos) {
    super(context, R.layout.list_item2, videos);

    this.context = context;
    this.videos = videos;
}

/* private view holder class */
private class ViewHolder {
    ImageView imageView;
    TextView txtSuccess;
    TextView txtCmd;
    TextView txtPrice;
}

public void run() {
    Intent intent = new Intent(context, ViewVideo.class);
    String txt=Cmd.getVideoURL(); 
    intent.putExtra("videofilename", txt);
    context.startActivity(intent);
}



public Cmd getItem(int position) {
    return videos.get(position);
}

public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    LayoutInflater inflater = context.getLayoutInflater();
    if (convertView == null) {
        convertView = inflater.inflate(R.layout.list_item2, null);
        holder = new ViewHolder();
        holder.txtSuccess = (TextView) convertView
                .findViewById(R.id.success);
        holder.txtCmd = (TextView) convertView.findViewById(R.id.cmd);
        holder.txtPrice = (TextView) convertView.findViewById(R.id.price);
        holder.imageView = (ImageView) convertView
                .findViewById(R.id.thumbnail);
        convertView.setTag(holder);

    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    final Cmd cmd = (Cmd) getItem(position);

    holder.txtSuccess.setText(cmd.getVideoName());
    holder.txtSuccess.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            run();
        }
    });
    holder.txtCmd.setText(cmd.getCmd());
    holder.txtCmd.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            run();
        }
    });

    holder.txtPrice.setText(cmd.getVideoURL() + "");
    holder.txtPrice.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            run();
        }
    });

    holder.imageView.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            run();
        }
    });
    return convertView;

}

 }

Cmd.java

public class Cmd implements ListAdapter {
    private String success;
    private String cmd;
    List<Cmd> videos;
    private String video;
    private String numberofvideos;
    private  String videoname;
    private  String videourl;
    private LayoutInflater mInflater;
    Button fav_up_btn1;
    Button fav_dwn_btn1;
    Context my_context;

     Bitmap imageBitmap;




    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // If convertView wasn't null it means we have already set it to our
        // list_item_user_video so no need to do it again
        if (convertView == null) {
            // This is the layout we are using for each row in our list
            // anything you declare in this layout can then be referenced below
            convertView = mInflater.inflate(R.layout.list_item_user_video,
                    parent, false);
        }
        // We are using a custom imageview so that we can load images using urls
        ImageView thumb = (ImageView) convertView
                .findViewById(R.id.userVideoThumbImageView);
        //thumb.setScaleType(ScaleType.FIT_XY);
        TextView title = (TextView) convertView
                .findViewById(R.id.userVideoTitleTextView);
        TextView uploader = (TextView) convertView
                .findViewById(R.id.userVideouploaderTextView);

        TextView viewCount = (TextView) convertView
                .findViewById(R.id.userVideoviewsTextView);
        uploader.setText(videos.get(position).getTitle());
        viewCount.setText(videos.get(position).getviewCount() + " views");

        fav_up_btn1 = (Button) convertView.findViewById(R.id.fav_up_btn1);
        fav_up_btn1.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                boolean favIsUp = fav_up_btn1
                        .getBackground()
                        .getConstantState()
                        .equals(my_context.getResources()
                                .getDrawable(R.drawable.fav_up_btn1)
                                .getConstantState());

                // set the background
                fav_up_btn1
                .setBackgroundResource(favIsUp ? R.drawable.fav_dwn_btn1
                        : R.drawable.fav_up_btn1);
            }
        });

        // Get a single video from our list
        final Cmd video = videos.get(position);
        // Set the image for the list item
//  /   thumb.setImageDrawable(video.getThumbUrl());
        //thumb.setScaleType(ScaleType.FIT_XY);
        // Set the title for the list item
        title.setText(video.getTitle());
        uploader.setText("by " + video.getUploader() + " |  ");

        return convertView;
    }

    public String getUploader() {
        // TODO Auto-generated method stub
        return null;
    }

    public String getviewCount() {
        // TODO Auto-generated method stub
        return null;
    }

    public CharSequence getTitle() {
        // TODO Auto-generated method stub
        return null;
    }

    public String getCmd() {
        return cmd;
    }

    public void setCmd(String cmd) {
        this.cmd = cmd;
    }
    public String getSuccess() {
        return success;
    }

    public void setSuccess(String success) {
        this.success = success;
    }

    public String getNumberOfVideos() {
        return numberofvideos;
    }
    public void setNumberOfVideos(String numberofvideos) {
        this.numberofvideos = numberofvideos;
    }
    public List<Cmd> getVideos() {
        return videos;
    }
    public void setVideos(List<Cmd> videos) {
        this.videos = videos;
    }
    public String getVideo() {
        return video;
    }
    public void setVideo(String video) {
        this.video = video;
    }
    public  String getVideoName() {
        return videoname;
    }

    public void setVideoName(String videoname) {
        this.videoname = videoname;
    }
    public  String getVideoURL() {
        return videourl;
    }

    public void setVideoURL(String videourl) {
        this.videourl = videourl;
    }

    @Override
    public int getCount() {
        return videos.size();
    }

    @Override
    public Object getItem(int position) {
        return videos.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public int getItemViewType(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public int getViewTypeCount() {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean isEmpty() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void registerDataSetObserver(DataSetObserver observer) {
        // TODO Auto-generated method stub

    }

    @Override
    public void unregisterDataSetObserver(DataSetObserver observer) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean areAllItemsEnabled() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean isEnabled(int position) {
        // TODO Auto-generated method stub
        return false;
    }

    public String getId() {
        // TODO Auto-generated method stub
        return null;
    }



}

Answer 1

The error message says it all: you cannot call a non-static method from a static context. You need to create an instance of the class that holds that particular method and call the method on this object. That way you don't have to make fields static either.

You're trying to call getVideoUrl() on Cmd , but you need to create an instance first:

Cmd cmd = new Cmd();
String txt = cmd.getVideoURL();

I strongly encourage to read through the official tutorial on this subject !

Answer 2

You're almost there. Try this:

public View getView(int position, View convertView, ViewGroup parent) {
. . .
  final Cmd cmd = (Cmd) getItem(position);

    holder.txtSuccess.setText(cmd.getVideoName());
    holder.txtSuccess.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            run(cmd);
        }
    });
. . .
}

public void run(Cmd cmd) {
    Intent intent = new Intent(context, ViewVideo.class);
    String txt=cmd.getVideoURL(); 
    intent.putExtra("videofilename", txt);
    context.startActivity(intent);
}

It looks like you're referencing the Cmd object using the static-style syntax because it's not reachable the way you wrote the code. The code above allows you to pass the Cmd object to the run() method, where it may be accessed.

HTH

Answer 3

您应该问自己，要在run方法中显示哪个视频URL - 数据结构中没有任何static视频URL。