使 ListView 平滑滾動

Question

我有以下代碼來加載我的 ListView（每個項目都有一個圖像和文本）：

public View getView(final int i, View convertView, ViewGroup viewGroup) {
    View view = inflater.inflate(R.layout.contact_inflater, null);
    final Holder holder = new ContactAdapter.Holder();

    holder.ivPhoto = (ImageView) view.findViewById(R.id.ivImage);
    holder.tvFullName = (TextView) view.findViewById(R.id.tvName);
    holder.tvPhoneNumber = (TextView) view.findViewById(R.id.tvPhoneNo);
    holder.tvFullName.setText(Contact.get(i).get(0));
    holder.tvPhoneNumber.setText(Contact.get(i).get(1));
    holder.button = (Button) view.findViewById(R.id.ivButton);
        
    Picasso.with(context)
                .load(Contact.get(i).get(2))
                .into(holder.ivPhoto);
    
    return view;
}

問題是列表滾動不順暢。 我如何使它平滑？

編輯：我已更改為 RecycleView 但我忘記添加以下代碼：

if(//IF//){ 
    Log.d("InInIn!", "InInIn!"); 
    
    //Turn to Tagged
}

當我把它變成一個 RecycleView 時，按鈕會在整個節奏中變成 Tagged 並且被標記的按鈕會隨着滾動而變化。 即使它們不應該改變，按鈕也在各處發生變化。 這是什么問題？

Answer 1

您應該改用recyclerView 。 它是 ListView 的更高級和更靈活的版本。 通過https://developer.android.com/guide/topics/ui/layout/recyclerview獲取指南。

如果您想堅持使用 ListView，那么為了提高性能，您應該回收/重用用戶不再可見的視圖。

public View getView(final int i, View convertView, ViewGroup viewGroup) {
       
    Holder holder = null;
    if(convertView == null){
        convertView = inflater.inflate(R.layout.contact_inflater, null);
        final Holder holder = new ContactAdapter.Holder();
        holder.ivPhoto = (ImageView) convertView.findViewById(R.id.ivImage);
        holder.tvFullName = (TextView) convertView.findViewById(R.id.tvName);
        holder.tvPhoneNumber = (TextView) convertView.findViewById(R.id.tvPhoneNo);
        holder.button = (Button) convertView.findViewById(R.id.ivButton);
        convertView.setTag(holder)
    }
    else{
        holder = (Holder)convertView.getTag()
    } 

    holder.tvFullName.setText(Contact.get(i).get(0));
    holder.tvPhoneNumber.setText(Contact.get(i).get(1));

    Picasso.with(context)
                .load(Contact.get(i).get(2))
                .into(holder.ivPhoto);

    return convertView;
}

Answer 2

您可以調試和檢查接收到畢加索的內容，您添加：un listener for watch the error

        .into(ontact.get(i).get(2), new Callback() {
            @Override
            public void onSuccess() {
            }

            @Override
            public void onError(Exception e) {
            }
        })

Answer 3

public View getView(final int i, View convertView, ViewGroup viewGroup) {
    Holder holder;
    if(null == convertView){
        holder = new ContactAdapter.Holder();
        convertView = inflater.inflate(R.layout.contact_inflater, null);
        holder.ivPhoto = (ImageView) view.findViewById(R.id.ivImage);
        holder.tvFullName = (TextView) view.findViewById(R.id.tvName);
        holder.tvPhoneNumber = (TextView) view.findViewById(R.id.tvPhoneNo);
        holder.button = (Button) view.findViewById(R.id.ivButton);
        converView.setTag(holder);
    }else{
        holder = (Holder) convertView.getTag();
    }
    holder.tvFullName.setText(Contact.get(i).get(0));
    holder.tvPhoneNumber.setText(get(i).get(1));
    Picasso.with(context)
                    .load(Contact.get(i).get(2))
                    .into(holder.ivPhoto);
    return view;
}

Answer 4

您必須在列表適配器中使用數據綁定並獲取布局組件，而無需在 getView 方法中使用 findViewById。

Answer 5

嘗試這個：

這是新的和更新的 getView 滾動更快

@Override
public View getView(int position, View convertView, ViewGroup paramViewGroup) {
    Object current_event = mObjects.get(position);
    ViewHolder holder = null;

    if (convertView == null) {
        holder = new ViewHolder();
        convertView = inflater.inflate(R.layout.row_event, null);
        holder.ThreeDimension = (ImageView) convertView.findViewById(R.id.ThreeDim);
        holder.EventPoster = (ImageView) convertView.findViewById(R.id.EventPoster);
        // This will now execute only for the first time of each row
        RelativeLayout.LayoutParams imageParams = new RelativeLayout.LayoutParams(measuredwidth, rowHeight);
        holder.EventPoster.setLayoutParams(imageParams);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    // This way you can simply avoid conditions
    holder.ThreeDimension.setVisibility(object.getVisibility());

    return convertView;
}