Question

我有一个ListView，我使用ListView填充TextView，使用自定义适配器填充Button.I已为Button中的custom adapter生成了点击事件在那个点击事件中，我正在尝试更改按钮文本和颜色，到这里工作正常，但是当我向上和向下滚动ListView其他按钮更改的文本颜色时。我过去几天就在这里停下来......

public class CustomAdapter extends BaseAdapter {

Activity a;
ArrayList<String> Rollno;
ArrayList<String> Stdname;
ArrayList<String> Stdstatus;

public CustomAdapter(Activity a, ArrayList<String> rollno, ArrayList<String> stdname, ArrayList<String> stdstatus) {
    this.a = a;
    Rollno = rollno;
    Stdname = stdname;
    Stdstatus = stdstatus;
}


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

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

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


public  class ViewHolder{
    TextView rollno,name;
    Button status;
}



@Override
public View getView(final int position, View convertView, ViewGroup parent) {
     final  ViewHolder viewHolder=new ViewHolder();
    LayoutInflater li=a.getLayoutInflater();
    View v=li.inflate(R.layout.custom,parent,false);
    viewHolder.rollno=(TextView)v.findViewById(R.id.crollno);
    viewHolder.name=(TextView)v.findViewById(R.id.cname);
    viewHolder.status=(Button)v.findViewById(R.id.btn1);


    viewHolder.rollno.setText(Rollno.get(position));
    viewHolder.name.setText(Stdname.get(position));
    viewHolder.status.setText(Stdstatus.get(position));

   viewHolder.status.setTag(0);
    viewHolder.status.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

           final int status1 = (Integer) v.getTag();

            if (status1 == 1) {
                viewHolder.status.setText("P");
                viewHolder.status.setBackgroundColor(Color.GREEN);

                v.setTag(0);
            } else if (status1 == 2) {
                viewHolder.status.setText("A");
                viewHolder.status.setBackgroundColor(Color.RED);
                v.setTag(1);
            } else if (status1 == 3) {
                viewHolder.status.setText("L");
                viewHolder.status.setBackgroundColor(Color.BLUE);
                v.setTag(2);
            } else {
                viewHolder.status.setText("H");
                viewHolder.status.setBackgroundColor(Color.YELLOW);
                v.setTag(3);

            }

        }
    });
    return v;
}
}

Answer 1

看起来你正在覆盖你的标签，导致你的按钮逻辑无法正常工作。

viewHolder.status.setTag(0);

通常你会这样做：

if (convertview == null){
  //create and initialize new viewholder and pass it to the views tag field
  //initialize the status tag here and dont set it again later
}else{
 //get your viewholder from the views tag
}
//update your values

Example：

@Override
public View getView(int position, View convertView, ViewGroup parent) {

ViewHolderItem viewHolder;

/*
 * The convertView argument is essentially a "ScrapView" as described is Lucas post 
 * http://lucasr.org/2012/04/05/performance-tips-for-androids-listview/
 * It will have a non-null value when ListView is asking you recycle the row layout. 
 * So, when convertView is not null, you should simply update its contents instead of inflating a new row layout.
 */
if(convertView==null){

    // inflate the layout
    LayoutInflater inflater = ((Activity) mContext).getLayoutInflater();
    convertView = inflater.inflate(layoutResourceId, parent, false);

    // well set up the ViewHolder
    viewHolder = new ViewHolderItem();
    viewHolder.textViewItem = (TextView) convertView.findViewById(R.id.textViewItem);

    // store the holder with the view.
    convertView.setTag(viewHolder);

}else{
    // we've just avoided calling findViewById() on resource everytime
    // just use the viewHolder
    viewHolder = (ViewHolderItem) convertView.getTag();
}

// object item based on the position
ObjectItem objectItem = data[position];

// assign values if the object is not null
if(objectItem != null) {
    // get the TextView from the ViewHolder and then set the text (item name) and tag (item ID) values
    viewHolder.textViewItem.setText(objectItem.itemName);
    viewHolder.textViewItem.setTag(objectItem.itemId);
}

return convertView;

}

Answer 2

使用卡片查看同样的问题我面对这样使用。

              if (readvalue.equals("0")) {
        holder.cardView.setCardBackgroundColor(context.getResources().getColor(R.color.texthintcolor));
        //  holder.itemView.setBackgroundResource(0);
        //cardView.setRadius(5);

    } else {
        //     holder.itemView.setBackgroundColor());
        holder.cardView.setCardBackgroundColor(context.getResources().getColor(R.color.winter));


        // cardView.setRadius(5);

    }

Answer 3

将此＆＃39; viewHolder.status.setTag（0）;＆＃39;下面是onClickListener，我认为它会起作用

 viewHolder.status.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

       final int status1 = (Integer) v.getTag();

        if (status1 == 1) {
            viewHolder.status.setText("P");
            viewHolder.status.setBackgroundColor(Color.GREEN);

            v.setTag(0);
        } else if (status1 == 2) {
            viewHolder.status.setText("A");
            viewHolder.status.setBackgroundColor(Color.RED);
            v.setTag(1);
        } else if (status1 == 3) {
            viewHolder.status.setText("L");
            viewHolder.status.setBackgroundColor(Color.BLUE);
            v.setTag(2);
        } else {
            viewHolder.status.setText("H");
            viewHolder.status.setBackgroundColor(Color.YELLOW);
            v.setTag(3);

        }

    }
});
viewHolder.status.setTag(0);
return v;

} }

Answer 4

基本上你需要存储位置状态。用以下代码替换您的适配器。

class CustomAdapter extends BaseAdapter {

        Activity a;
        ArrayList<String> Rollno;
        ArrayList<String> Stdname;
        ArrayList<String> Stdstatus;
        HashMap<Integer, Integer> statusArray = new HashMap<>();

        public CustomAdapter(Activity a, ArrayList<String> rollno, ArrayList<String> stdname, ArrayList<String> stdstatus) {
            this.a = a;
            Rollno = rollno;
            Stdname = stdname;
            Stdstatus = stdstatus;
        }


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

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

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


        public  class ViewHolder{
            TextView rollno,name;
            Button status;
        }



        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            final  ViewHolder viewHolder=new ViewHolder();
            LayoutInflater li=a.getLayoutInflater();
            View v=li.inflate(R.layout.custom,parent,false);
            viewHolder.rollno=(TextView)v.findViewById(R.id.crollno);
            viewHolder.name=(TextView)v.findViewById(R.id.cname);
            viewHolder.status=(Button)v.findViewById(R.id.btn1);


            viewHolder.rollno.setText(Rollno.get(position));
            viewHolder.name.setText(Stdname.get(position));
            viewHolder.status.setText(Stdstatus.get(position));

            int status = statusArray.get(position) != null ? statusArray.get(position) : 0;
            switch (status){
                case 1:
                    viewHolder.status.setText("P");
                    viewHolder.status.setBackgroundColor(Color.GREEN);
                    break;
                case 2:
                    viewHolder.status.setText("A");
                    viewHolder.status.setBackgroundColor(Color.RED);
                    break;
                case 3:
                    viewHolder.status.setText("L");
                    viewHolder.status.setBackgroundColor(Color.BLUE);
                    break;
                default:
                    viewHolder.status.setText("H");
                    viewHolder.status.setBackgroundColor(Color.YELLOW);
                    break;
            }

            viewHolder.status.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    int status1 = statusArray.get(position) != null ? statusArray.get(position) : 0;
                    if (status1 == 1) {
                        statusArray.put(position, 0);
                    } else if (status1 == 2) {
                        statusArray.put(position, 1);
                    } else if (status1 == 3) {
                        statusArray.put(position, 2);
                    } else {
                        statusArray.put(position, 3);
                    }

                    notifyDataSetChanged();
                }
            });
            return v;
        }
    }

Answer 5

每次访问前景时都会重新创建视图，因此只有视图位置才能真正唯一。您可以创建视图位置的Hashmap和您自己的标记（整数），而不是使用视图标记。每次创建视图时，都会检查hashmap中是否存在位置，并根据hashmap标记设置按钮颜色。放置

行

private HashMap<Integer,Integer> tagMap = new HashMap<>();

在customAdapter的开头。在getView中检查是否添加了位置，如果没有添加相应的按钮标记

int tag=1; //desired default tag for button
   //add to hashmap if not exist
 if(!tagMap.containsKey(position)){
        tagMap.put(position,tag);
    }

在onclick listerner中，您可以按位置获取hasmap标记并相应地设置按钮颜色

   final int status1 = tagMap.get(position);;

        if (status1 == 1) {
            viewHolder.status.setText("P");
            viewHolder.status.setBackgroundColor(Color.GREEN);

            tagMap.put(position,0);//this will update tag for current position
        } else if (status1 == 2) {
            viewHolder.status.setText("A");
            viewHolder.status.setBackgroundColor(Color.RED);
           tagMap.put(position,1);
        } else if (status1 == 3) {
            viewHolder.status.setText("L");
            viewHolder.status.setBackgroundColor(Color.BLUE);
            tagMap.put(position,2);
        } else {
            viewHolder.status.setText("H");
            viewHolder.status.setBackgroundColor(Color.YELLOW);
          tagMap.put(position,3);
        }

希望这有帮助

滚动时更改ListView项中按钮的文本

5 个答案: