Android的ArrayAdapter每一次viewholder给予不同的结果 [英] Android ArrayAdapter with viewholder giving different result every time

问题描述

我有一个列表视图定制ArrayAdapter。我有两个类型的pretty多，除了像背景和路线的一些东西图形相同内容的行。

I have a custom ArrayAdapter for a listview. I have two types of rows with pretty much the same content except some graphical things like background and alignments.

这是什么样子：

public class ChatAdapter extends ArrayAdapter<MessageSource.Message> {

private Context context;
private List<MessageSource.Message> items;
private int deviceId;

public ChatAdapter(Context context, int layoutResourceId, List<MessageSource.Message> items, int deviceId) {
    super(context, layoutResourceId, items);
    this.context = context;
    this.items = items;
    this.deviceId = deviceId;
}

static class ViewHolder {
    protected TextView from;
    protected TextView message;
    protected TextView time;
}

@Override
public View getView(int p, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    ViewHolder viewHolder ;
    if(convertView == null) {
        if (items.get(p).deviceId == deviceId) {
            convertView = inflater.inflate(R.layout.chat_row_right, parent, false);
        } else {
            convertView = inflater.inflate(R.layout.chat_row_left, parent, false);
        }
        viewHolder = new ViewHolder();
        viewHolder.from = (TextView) convertView.findViewById(R.id.bubble_from);
        viewHolder.message = (TextView) convertView.findViewById(R.id.bubble_message);
        viewHolder.time = (TextView) convertView.findViewById(R.id.bubble_time);

        viewHolder.from.setTypeface(Font.rLight(context));
        viewHolder.message.setTypeface(Font.rLight(context));
        viewHolder.time.setTypeface(Font.rLight(context));

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

    viewHolder.from.setText(items.get(p).nickName);
    viewHolder.message.setText(items.get(p).message);
    viewHolder.time.setText(DateUtils.getRelativeTimeSpanString(items.get(p).created * 1000, System.currentTimeMillis(), 0));

    return convertView;
}
}

通过这条线我决定使用哪个布局的：

With this line I determine which of the layouts to use:

if (items.get(p).deviceId == deviceId) {

但它似乎是随机忽略，选择布局，因为它看到适合。
我做错了什么在这里的任何想法？

But it seems to be randomly ignored and chooses the layout as it see fits. Any ideas of what I'm doing wrong here?

推荐答案

您正在检查的DeviceID只有当convertView == NULL。为了得到正确的结果，你也应该检查什么布局convertView为您提供的包含，如果它是不正确类型的充气一个新的。

You are checking deviceId only when convertView == null. To get correct result you should also check what layout convertView offered to you contains and if it is not of correct type inflate a new one.

幸运的ListView有像你这样的情况下支持 - 覆盖getViewTypeCount和getItemViewType如下：

Fortunately listview has support for situations like yours - override getViewTypeCount and getItemViewType as follows:

@Override
public int getItemViewType( int p ) {
    return items.get(p).deviceId == deviceId ? 0 : 1;
}

@Override
public int getViewTypeCount() {
    return 2;
}

然后，你就不必检查视图类型，因为列表视图处理这张支票给你 - 它缓存您单独使用全部视图类型，并将正确的您getView方法

Then you do not have to check View type because listview handles this check for you - it caches all view types you use separately and passes correct one to your getView method.

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