Setting image resourse by obtaining tag position for an imageview android

问题

I am making use of recycler view. I have a layout that is highlighted in light red,this layout is included for each item in the recycler view. The light red layout is placed over the background image. I am using setTag method to identify the clicks of the buttons in red layout. That is working properly when i click i get the position. The problem is i want to change the image at specific position. For example : Consider the heart button. I have set a tag on it like this.

heartButton = findViewById(id); heartButton.setTag(position);

now i get the position by using the getTag method. But now i want to change the image of the heartButton at the a specific position. Is there something like

heartButton.getTag(position).setImageResouce(drawable);

If not how do i do this then.

回答1:

use setBackgroundResource(R.drawable.XXX)

http://developer.android.com/reference/android/view/View.html#setBackgroundResource(int)

回答2:

Proper way to do this is, You have to keep the state of the heart button stored in the model(POJO) which is passed to custom adapter. e.g.

class ModelListItem{
public static final int HEART=1,BROKEN_HEART=2;

int heartButtonState;

}

Now in onClick() of heart button, get that object from adapter using position,cosidering you have already figured it out on how to preserve position from heart button

ModelListItem item = (ModelListItem)adapter.getItem(position)

Change the state of heart button;

item.setHeartButtonState(ModelListItem.BROKEN_HEART);
   adapter.notifyDatasetChanged();

You already know below explaination but just in case To work this properly,in your getView methode of adapter you need to put the check on heartButtonState(); and use appropriate image resource.

getView(BOILERPLATE){
 BOILERPLATE

 switch(item.getheartButtonState()){
 case ModelItemList.HEART:
   heartbutton.setImageResource(heart_image);
 break;
 case ModelItemList.BROKEN_HEART:
   heartbutton.setImageResource(broken_heart_image);
 break;  
 } 

回答3:

I made a custom click listener and updated the like in the setter getter.But this works only when the view has been moved out of the view (i think it is the scrapeview)

The Setter Getter Class

public class DemoData {

    int background;
    boolean liked;

    public DemoData(int background) {
        this.background = background;
    }

    public int getBackground() {
        return background;
    }

//    public void setBackground(int background) {
//        this.background = background;
//    }

    public boolean isLiked() {
        return liked;
    }

    public void setLiked(boolean liked) {
        this.liked = liked;
    }
}

The onBindViewHolder function of the recycler view

@Override
    public void onBindViewHolder(ViewHolder holder, int position) {


        background = (ImageView) holder.view.findViewById(R.id.image);
        layout = (LinearLayout) holder.view.findViewById(R.id.layout);

        delete = (ImageView) layout.findViewById(R.id.delete);
        lock = (ImageView) layout.findViewById(R.id.lock);


        delete.setTag("delete_"+position);
        lock.setTag("lock_"+position);

        if(Constants.demoDatas.get(position).isLiked()){
            delete.setImageResource(R.drawable.ic_launcher);
        }
        else{
            delete.setImageResource(android.R.drawable.ic_delete);
        }

        delete.setOnClickListener(new CustomClickListener(position));
        lock.setOnClickListener(new CustomClickListener(position));



    }

The custom click listener is as below

public class CustomClickListener implements View.OnClickListener {

    int position;


    public CustomClickListener(int position) {

        this.position = position;
    }

    @Override
    public void onClick(View v) {

        String tag = (String) v.getTag();
        String identifier[] = tag.split("_");

        // this line saves my state in the Setter Getter Class
        Constants.demoDatas.get(position).setLiked(true);

    }
}

来源：https://stackoverflow.com/questions/28045149/setting-image-resourse-by-obtaining-tag-position-for-an-imageview-android