android - 自定义 ListView 不会替换 View

Question

我正在使用自定义 Adapter 在 listView 中显示图像和文本。单击按钮时，我想用下一张图像替换图像。但这只是在列表末尾添加而不是替换。下面是我的代码 fragment :

从sqlite中获取图片的方法

    public void BlockData() {       
    dataBase = dbHelper.getReadableDatabase();
    Cursor mCursor = dataBase.rawQuery("SELECT * FROM "+ dbHelper.TABLE_NAME + " WHERE " + dbHelper.KEY_HNUM+ "=" + id, null);

        if (mCursor.moveToFirst()) {
            do {
                category_Id.add(mCursor.getString(mCursor.getColumnIndex(dbHelper.KEY_HNUMM)));             
            } while (mCursor.moveToNext());     
            lv.setAdapter(new BlockAdapter(getApplicationContext(),category_Id,prgmImages));

            stopManagingCursor(mCursor);
            mCursor.close();
        }   
    }

在自定义 View 中设置

public View getView(final int pos, View child, final ViewGroup parent) {
    final Holder mHolder;
    LayoutInflater layoutInflater;
    if (child == null) {
        layoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        child = layoutInflater.inflate(R.layout.secondlist, null);
        mHolder = new Holder();
        mHolder.txt_id = (TextView) child.findViewById(R.id.testingg);
        mHolder.tx_img = (ImageView) child.findViewById(R.id.sac_img);
        mHolder.butnxt = (Button) child.findViewById(R.id.button2);
        mHolder.butpre = (Button) child.findViewById(R.id.button1);
        child.setTag(mHolder);
    } else {   
        mHolder = (Holder) child.getTag();
    }

    mHolder.txt_id.setText(category_Id.get(pos));

    if (pos == 0) {
        imgs = getResources().obtainTypedArray(R.array.sac_imgs);

        mHolder.tx_img.setImageResource(imgs.getResourceId(id - 1, -1));
        imgs.recycle();
    }else{
        imgs = getResources().obtainTypedArray(R.array.sac_imgs);
            mHolder.tx_img.setImageResource(imgs.getResourceId(pos - 1, -1));
        imgs.recycle();
    }       
    mHolder.butnxt.setOnClickListener(new OnClickListener() {                    
        @Override
        public void onClick(View v) {
            id++;
            BlockData();
        }
    });                             
    return child;
}
protected ViewGroup findViewById(int txtViewPop) {
    return null;
}
public class Holder {
    TextView txt_id;
    Button butnxt;
    Button butpre;
    TextView txt_fDate;
    ImageView tx_img;           
}

每次单击按钮时我应该怎么做才能替换 View ？我希望有人能指导我正确的方向。提前致谢

Answer 1

What should i do to replace the view every time a button is clicked?

不要在 ListView 中添加新的 Adapter 对象:

1.在BlockAdapter中创建一个清除所有数据的方法:

public void refeshAdapterData(List category_Id,<Data_Type> prgmImages )
    {
        category_Id.clear(); 
        // clear prgmImages
        // add data to adapter
        category_Id.addAll(category_Id);
        // Add prgmImages 
        notifyDataSetChanged();
    }

2. 从 BlockData() 方法调用 refeshAdapterData :

refeshAdapterData(category_Id,prgmImages);
stopManagingCursor(mCursor);
mCursor.close();