我是一个机器人初学者，我想不通为什么会这样。请帮忙！

活动截图：

一切正常，除了当我向下滚动（因此我认为这与回收做）......所以，当我向后滚动起来，试图撤消后的第一个投票（红色箭头）...它认为职位是否决！此外，它也可能认为向下票ImageButton的绘制是空的 - 见code）。如果我不滚动，它完美的作品。

getView code：

 公共查看getView（INT位置，查看convertView，父母的ViewGroup）{    ViewHolder持有人;    如果（convertView == NULL）{        持有人=新ViewHolder（）;        //充气列表项        convertView = this.inflater.inflate（R.layout.row_layout，父母，假）;        //获取意见        holder.profilePic =（ImageView的）convertView.findViewById（R.id.profilePic）;        holder.username =（TextView中）convertView.findViewById（R.id.username）;        holder.day =（TextView中）convertView.findViewById（R.id.day）;        holder.rating =（TextView中）convertView.findViewById（R.id.rating）;        holder.textPost =（TextView中）convertView.findViewById（R.id.textPost）;        holder.ratingUp =（的ImageButton）convertView.findViewById（R.id.ratingUp）;        holder.ratingDown =（的ImageButton）convertView.findViewById（R.id.ratingDown）;        convertView.setTag（保持器）;    }其他{        支架=（ViewHolder）convertView.getTag（）;    }    。最终绘制对象up_clicked = context.getResources（）getDrawable（R.drawable.ic_action_rate_up_clicked）;    最终绘制对象up_unClicked = context.getResources（）getDrawable（R.drawable.ic_action_rate_up）。    最终绘制对象down_clicked = context.getResources（）getDrawable（R.drawable.ic_action_rate_down_clicked）。    最终绘制对象down_unClicked = context.getResources（）getDrawable（R.drawable.ic_action_rate_down）。    后后= cityFeed.get（位置）;    holder.profilePic.setImageResource（post.getDrawableID（））;    holder.username.setText（post.getUsername（））;    holder.day.setText（post.getDay（））;    holder.rating.setText（post.getRating（））;    holder.textPost.setText（post.getText（））;    DB =新数据库处理器（背景）;    字符串userVotesUp = NULL;    userVotesUp = db.getUserVotes（上）;    如果（userVotesUp == NULL）{        userVotesUp =;    }    字符串userVotesDown = NULL;    userVotesDown = db.getUserVotes（下）;    如果（userVotesDown == NULL）{        userVotesDown =;    }    字符串postid = post.getPostID（）;    如果（userVotesUp.contains（帖子ID））{        holder.ratingUp.setImageDrawable（up_clicked）;    }否则如果（userVotesDown.contains（帖子ID）及＆放大器;！userVotesUp =空）{        holder.ratingDown.setImageDrawable（down_clicked）;    }其他{        holder.ratingUp.setImageDrawable（up_unClicked）;        holder.ratingDown.setImageDrawable（down_unClicked）;    }    db.close（）;    holder.ratingUp.setTag（位置）;    holder.ratingDown.setTag（位置）;    holder.ratingUp.setOnClickListener（新OnClickListener（）{        @覆盖        公共无效的onClick（查看convertView）{            //使用按钮标签后获得的详细信息            INT POS =（整数）convertView.getTag（）;            后后= cityFeed.get（POS）            字符串postid = post.getPostID（）;            串ratingString = post.getRating（）;            INT ratingValue =的Integer.parseInt（ratingString）;            RelativeLayout的父=（RelativeLayout的）convertView.getParent（）的getParent（）。            TextView的ratingView =（TextView中）parent.findViewById（R.id.rating）;            的ImageButton起来=（的ImageButton）parent.findViewById（R.id.ratingUp）;            的ImageButton下来=（的ImageButton）parent.findViewById（R.id.ratingDown）;            //如果后期不否决？            如果（down.getDrawable（）== down_unClicked）{                //如果该信息是没有投票起来......                如果（up.getDrawable（）== up_unClicked）{                    up.setImageDrawable（up_clicked）;                    ratingValue = ratingValue + 1;                    ratingString = Integer.toString（ratingValue）;                    ratingView.setText（ratingString）;                    post.setRating（ratingString）;                    wsAsync =新WebServiceAsync（背景）;                    wsAsync.execute（voteTag，帖子ID，向上）;                //否则职位是投了...                }其他{                    up.setImageDrawable（up_unClicked）;                    ratingValue = ratingValue  -  1;                    ratingString = Integer.toString（ratingValue）;                    ratingView.setText（ratingString）;                    post.setRating（ratingString）;                    wsAsync =新WebServiceAsync（背景）;                    wsAsync.execute（voteTag，帖子ID，下）;                }            //否则职位是否决...            }其他{                down.setImageDrawable（down_unClicked）;                up.setImageDrawable（up_clicked）;                ratingValue = ratingValue + 2;                ratingString = Integer.toString（ratingValue）;                ratingView.setText（ratingString）;                post.setRating（ratingString）;                wsAsync =新WebServiceAsync（背景）;                wsAsync.execute（voteTag，帖子ID，upDownAlready）;            }        }    }）;    holder.ratingDown.setOnClickListener（新OnClickListener（）{        @覆盖        公共无效的onClick（查看convertView）{            //使用按钮标签后获得的详细信息            INT POS =（整数）convertView.getTag（）;            后后= cityFeed.get（POS）            字符串postid = post.getPostID（）;            串ratingString = post.getRating（）;            INT ratingValue =的Integer.parseInt（ratingString）;            RelativeLayout的父=（RelativeLayout的）convertView.getParent（）的getParent（）。            TextView的ratingView =（TextView中）parent.findViewById（R.id.rating）;            的ImageButton起来=（的ImageButton）parent.findViewById（R.id.ratingUp）;            的ImageButton下来=（的ImageButton）parent.findViewById（R.id.ratingDown）;            //如果该信息是没有投票起来......            如果（up.getDrawable（）== up_unClicked）{                //如果后期不否决？                如果（down.getDrawable（）== down_unClicked）{                    down.setImageDrawable（down_clicked）;                    ratingValue = ratingValue  -  1;                    ratingString = Integer.toString（ratingValue）;                    ratingView.setText（ratingString）;                    post.setRating（ratingString）;                    wsAsync =新WebServiceAsync（背景）;                    wsAsync.execute（voteTag，帖子ID，下）;                //否则职位是否决...                }其他{                    down.setImageDrawable（down_unClicked）;                    ratingValue = ratingValue + 1;                    ratingString = Integer.toString（ratingValue）;                    ratingView.setText（ratingString）;                    post.setRating（ratingString）;                    wsAsync =新WebServiceAsync（背景）;                    wsAsync.execute（voteTag，帖子ID，向上）;                }            //否则职位是投了...            }其他{                up.setImageDrawable（up_unClicked）;                down.setImageDrawable（down_clicked）;                ratingValue = ratingValue  -  2;                ratingString = Integer.toString（ratingValue）;                ratingView.setText（ratingString）;                post.setRating（ratingString）;                wsAsync =新WebServiceAsync（背景）;                wsAsync.execute（voteTag，帖子ID，downUpAlready）;            }        }    }）;    返回convertView;} 

解决方案

通过考虑您onClickListerners（上holder.ratingUp和holder.ratingDown）工作得很好，我认为这个问题是在code的这一部分

 如果（userVotesUp.contains（帖子ID））{    holder.ratingUp.setImageDrawable（up_clicked）;}否则如果（userVotesDown.contains（帖子ID）及＆放大器;！userVotesUp =空）{    holder.ratingDown.setImageDrawable（down_clicked）;}其他{    holder.ratingUp.setImageDrawable（up_unClicked）;    holder.ratingDown.setImageDrawable（down_unClicked）;} 

如果我没看错，你正在做的事情一样，你有3个条件，首先是

 如果（userVotesUp.contains（帖子ID）） 

这意味着评级upvoted，并要设置up_clicked imageDrawable，但你是不是down_unClicked图像绘制设置为holder.ratingDown。

第二个条件适用于本

 如果（userVotesUp.contains（帖子ID）） 

那么你down_clicked绘制设置为holder.ratingDown，但up_unClicked图像绘制不设置holder.ratingUp。

和第三个条件是既不upvoted也不downvoted这似乎是罚款。所以我觉得，你有这个替换code你的那部分。

 如果（userVotesUp.contains（帖子ID））{    holder.ratingUp.setImageDrawable（up_clicked）;    holder.ratingDown.setImageDrawable（down_unClicked）;}否则如果（userVotesDown.contains（帖子ID）及＆放大器;！userVotesUp =空）{    holder.ratingDown.setImageDrawable（down_clicked）;    holder.ratingUp.setImageDrawable（up_unClicked）;}其他{    holder.ratingUp.setImageDrawable（up_unClicked）;    holder.ratingDown.setImageDrawable（down_unClicked）;} 

希望这有助于.. !!

I'm an android beginner and I can't figure out why this is happening. Please help!

Activity Screenshot:

Everything works fine except when I scroll down (hence why I think it has to do with recycling)... So when I scroll back up and attempt to undo the vote (red arrow) on the first post... it thinks the post is voted down! Alternatively, it may also think the down-vote ImageButton drawable is empty - see code). If I don't scroll, it works perfectly.

getView code:

public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if (convertView == null) {
        holder = new ViewHolder();
        // inflate the list item
        convertView = this.inflater.inflate(R.layout.row_layout, parent, false);            
        // get views 
        holder.profilePic = (ImageView) convertView.findViewById(R.id.profilePic);
        holder.username = (TextView) convertView.findViewById(R.id.username);
        holder.day = (TextView) convertView.findViewById(R.id.day);
        holder.rating = (TextView) convertView.findViewById(R.id.rating);
        holder.textPost = (TextView) convertView.findViewById(R.id.textPost);
        holder.ratingUp = (ImageButton) convertView.findViewById(R.id.ratingUp);
        holder.ratingDown = (ImageButton) convertView.findViewById(R.id.ratingDown);
        convertView.setTag(holder);

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

    final Drawable up_clicked = context.getResources().getDrawable(R.drawable.ic_action_rate_up_clicked);
    final Drawable up_unClicked = context.getResources().getDrawable(R.drawable.ic_action_rate_up);
    final Drawable down_clicked = context.getResources().getDrawable(R.drawable.ic_action_rate_down_clicked);
    final Drawable down_unClicked = context.getResources().getDrawable(R.drawable.ic_action_rate_down);

    Post post = cityFeed.get(position);
    holder.profilePic.setImageResource(post.getDrawableID());
    holder.username.setText(post.getUsername());
    holder.day.setText(post.getDay());
    holder.rating.setText(post.getRating());
    holder.textPost.setText(post.getText());        

    db = new DatabaseHandler(context);
    String userVotesUp = null;
    userVotesUp = db.getUserVotes("up");
    if (userVotesUp == null) {
        userVotesUp = "";
    }
    String userVotesDown = null;
    userVotesDown = db.getUserVotes("down");
    if (userVotesDown == null) {
        userVotesDown = "";
    }
    String postID = post.getPostID();
    if (userVotesUp.contains(postID)) {
        holder.ratingUp.setImageDrawable(up_clicked);
    } else if (userVotesDown.contains(postID) && userVotesUp != null) {
        holder.ratingDown.setImageDrawable(down_clicked);
    } else {
        holder.ratingUp.setImageDrawable(up_unClicked);
        holder.ratingDown.setImageDrawable(down_unClicked);
    }
    db.close();

    holder.ratingUp.setTag(position);
    holder.ratingDown.setTag(position);

    holder.ratingUp.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View convertView) {

            // get post details using button tag
            int pos = (Integer)convertView.getTag();
            Post post = cityFeed.get(pos);
            String postID = post.getPostID();
            String ratingString = post.getRating();
            int ratingValue = Integer.parseInt(ratingString);               
            RelativeLayout parent = (RelativeLayout)convertView.getParent().getParent();
            TextView ratingView = (TextView)parent.findViewById(R.id.rating);
            ImageButton up = (ImageButton)parent.findViewById(R.id.ratingUp);
            ImageButton down = (ImageButton)parent.findViewById(R.id.ratingDown);

            // if the post is not voted down...
            if (down.getDrawable() == down_unClicked) {             
                // if the post is not voted up...
                if (up.getDrawable() == up_unClicked) { 
                    up.setImageDrawable(up_clicked);
                    ratingValue = ratingValue + 1;
                    ratingString = Integer.toString(ratingValue);
                    ratingView.setText(ratingString);           
                    post.setRating(ratingString);                   
                    wsAsync = new WebServiceAsync(context);
                    wsAsync.execute(voteTag, postID, "up");                     
                // else the post is voted up...
                } else {
                    up.setImageDrawable(up_unClicked);
                    ratingValue = ratingValue - 1;
                    ratingString = Integer.toString(ratingValue);
                    ratingView.setText(ratingString);
                    post.setRating(ratingString);
                    wsAsync = new WebServiceAsync(context);
                    wsAsync.execute(voteTag, postID, "down");
                }                           
            // else the post is voted down...
            } else {
                down.setImageDrawable(down_unClicked);
                up.setImageDrawable(up_clicked);
                ratingValue = ratingValue + 2;
                ratingString = Integer.toString(ratingValue);
                ratingView.setText(ratingString);
                post.setRating(ratingString);
                wsAsync = new WebServiceAsync(context);
                wsAsync.execute(voteTag, postID, "upDownAlready");
            }
        }
    });

    holder.ratingDown.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View convertView) {

            // get post details using button tag
            int pos = (Integer)convertView.getTag();
            Post post = cityFeed.get(pos);
            String postID = post.getPostID();
            String ratingString = post.getRating();
            int ratingValue = Integer.parseInt(ratingString);               
            RelativeLayout parent = (RelativeLayout)convertView.getParent().getParent();
            TextView ratingView = (TextView)parent.findViewById(R.id.rating);
            ImageButton up = (ImageButton)parent.findViewById(R.id.ratingUp);
            ImageButton down = (ImageButton)parent.findViewById(R.id.ratingDown);

            // if the post is not voted up...
            if (up.getDrawable() == up_unClicked) {             
                // if the post is not voted down...
                if (down.getDrawable() == down_unClicked) { 
                    down.setImageDrawable(down_clicked);
                    ratingValue = ratingValue - 1;
                    ratingString = Integer.toString(ratingValue);
                    ratingView.setText(ratingString);           
                    post.setRating(ratingString);                   
                    wsAsync = new WebServiceAsync(context);
                    wsAsync.execute(voteTag, postID, "down");                       
                // else the post is voted down...
                } else {
                    down.setImageDrawable(down_unClicked);
                    ratingValue = ratingValue + 1;
                    ratingString = Integer.toString(ratingValue);
                    ratingView.setText(ratingString);
                    post.setRating(ratingString);
                    wsAsync = new WebServiceAsync(context);
                    wsAsync.execute(voteTag, postID, "up");
                }                           
            // else the post is voted up...
            } else {
                up.setImageDrawable(up_unClicked);
                down.setImageDrawable(down_clicked);
                ratingValue = ratingValue - 2;
                ratingString = Integer.toString(ratingValue);
                ratingView.setText(ratingString);
                post.setRating(ratingString);
                wsAsync = new WebServiceAsync(context);
                wsAsync.execute(voteTag, postID, "downUpAlready");
            }
        }
    });
    return convertView;
}

By considering that your onClickListerners(on holder.ratingUp and holder.ratingDown) works fine, i think the problem is in this portion of your code

if (userVotesUp.contains(postID)) {
    holder.ratingUp.setImageDrawable(up_clicked);
} else if (userVotesDown.contains(postID) && userVotesUp != null) {
    holder.ratingDown.setImageDrawable(down_clicked);
} else {
    holder.ratingUp.setImageDrawable(up_unClicked);
    holder.ratingDown.setImageDrawable(down_unClicked);
}

If i am not wrong, you are doing something like that you have 3 conditions, First is

if (userVotesUp.contains(postID)) 

that means rating is upvoted and you are setting up_clicked imageDrawable, but you are not setting down_unClicked image drawable to holder.ratingDown.

second condition applies to this

if (userVotesUp.contains(postID)) 

then you are setting down_clicked drawable to holder.ratingDown, but not setting up_unClicked image drawable to holder.ratingUp.

and third condition is neither upvoted nor downvoted and that seems to be fine. so I think, you have to replace your that portion of code with this

if (userVotesUp.contains(postID)) {
    holder.ratingUp.setImageDrawable(up_clicked);
    holder.ratingDown.setImageDrawable(down_unClicked);
} else if (userVotesDown.contains(postID) && userVotesUp != null) {
    holder.ratingDown.setImageDrawable(down_clicked);
    holder.ratingUp.setImageDrawable(up_unClicked);
} else {
    holder.ratingUp.setImageDrawable(up_unClicked);
    holder.ratingDown.setImageDrawable(down_unClicked);
}

Hope this helps..!!