使用自定义适配器更改ListView中特定行中的ImageView

Posted 2021-05-03

我正在尝试更改ImageView中使用自定义适配器制作的特定行中的ListView。

每当我改变一行时，其他行也会受到影响。我很感激你的帮助。谢谢。这是我在MainActivity类中的代码

adapter= new CustomAdapter(dataModels,getApplicationContext());

listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Toast.makeText(MainActivity.this, position+" ",
                    Toast.LENGTH_LONG).show();

        DataModel dataModel= dataModels.get(position);
        Snackbar.make(view, dataModel.getName()+"
"+dataModel.getType(), Snackbar.LENGTH_LONG)
                    .setAction(" ", null).show();

        ImageView imgv = (ImageView)view.findViewById(R.id.item_info);
        imgv.setImageResource(R.drawable.fav);

        adapter.notifyDataSetChanged();

        i= Integer.parseInt(dataModel.getVersion_number());
        rotate();
        StartNewSong();

    }
});

这里是自定义适配器中的代码

public View getView(int position, View convertView, ViewGroup parent) {
    // Get the data item for this position
    DataModel dataModel = getItem(position);
    // Check if an existing view is being reused, otherwise inflate the view

    final View result;

    if (convertView == null) {


        viewHolder = new ViewHolder();
        LayoutInflater inflater = LayoutInflater.from(getContext());
        convertView = inflater.inflate(R.layout.row_item, parent, false);

        viewHolder.txtName = (TextView) convertView.findViewById(R.id.name);

        viewHolder.txtType = (TextView) convertView.findViewById(R.id.type);

        viewHolder.info = (ImageView) convertView.findViewById(R.id.item_info);

        result=convertView;

        convertView.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();
        result=convertView;
    }

    Animation animation = AnimationUtils.loadAnimation(mContext, (position > lastPosition) ? R.anim.up_from_bottom : R.anim.down_from_top);
    result.startAnimation(animation);
    lastPosition = position;


    viewHolder.txtName.setText(dataModel.getName());
    viewHolder.txtType.setText(dataModel.getType());
    check = dataModel.getImageApp();
    if (check == "false") {

    } else if (check !="false") {
        Picasso.get()
               .load(check)
               .placeholder(R.mipmap.ic_launcher)
               .error(R.mipmap.ic_launcher)
               .into(viewHolder.info);
    }

    viewHolder.info.setOnClickListener(this);
    viewHolder.info.setTag(position);

    // Return the completed view to render on screen
    return convertView;
}

这是一个问题，显示为gif problem as a gif

我的DataModel类

公共类DataModel {

String name;
String type;
String id;
String imageApp;
String url;


public DataModel(String name, String type, String id, String imageApp, String url) {
    this.name=name;
    this.type=type;
    this.id=id;
    this.imageApp=imageApp;
    this.url=url;

}


public String getName() {
    return name;
}


public String getType() {
    return type;
}


public String getVersion_number() {
    return id;
}
public String getImageApp() {
    return imageApp;
}
public String getUrl() {
    return url;
 }

}

答案

在isSelected类中创建一个名为DataModel的布尔变量，并按如下方式更改构造函数。

public DataModel(String name, String type, String id, String imageApp, String url, boolean isSelected) {
    this.name=name;
    this.type=type;
    this.id=id;
    this.imageApp=imageApp;
    this.url=url;
    this.isSelected = isSelected;
}

这将用于确定是否选择了某个项目。为isSelected创建getter和setter。当你创建DataModel对象时，将isSelected作为false传递给你的构造函数。

在适配器中，检查isSelected的值以设置相应的图像。

if (dataModel.isSelected) {
    Picasso.get()
           .load(your_selected_imageview)
           .placeholder(R.mipmap.ic_launcher)
           .error(R.mipmap.ic_launcher)
           .into(viewHolder.info);
}

并且在listview的项目中，单击侦听器不会更改imageview，而只需将相应isSelected对象的DataModel值设置为true。

DataModel dataModel = dataModels.get(position);
dataModel.setIsSelected(true);
adapter.notifyDataSetChanged();