Android listView 单元格回收与可变大小的单元格

Question

我有一个列表视图。单元格具有可变高度。这在回收电池时会导致问题——回收的电池可能有错误的高度。关闭回收会使滚动太不稳定。如何在回收电池的同时获得正确的高度？

编辑：各地的高度各不相同。没有可能的值的简短列表。

Answer 1

两格类型

通常问题来自getView。我不确定您真正在寻找什么，因为您没有提供自定义适配器。但是，我给你一个例子，有 2 种不同的单元格类型，但单元格只包含一个文本视图。

在这种情况下，所有单元格都已通过回收充分调整。仔细阅读并扩展/修改以满足您的需求。

在你的CustomAdapter

private final class CustomArrayAdapter extends ArrayAdapter<String> {
    //the fastest is to get the layout inflater once and not each time getView is called
    private LayoutInflater mInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    public CustomArrayAdapter(Context context, int resource, int textViewResourceId, String[] objects) {
        super(context, resource, textViewResourceId, objects);
    }

    ...

    //here depending on the item position determine if cell is of type 1 or 2
    @Override
    public int getItemViewType(int position) {
        if (/* your type 1 criteria is match */) {
            return TYPE_1;
        } else {
            return TYPE_2;
        }
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        int type = getItemViewType(position);
        if (convertView == null) {
            holder = new ViewHolder();
            switch (type) {
                case TYPE_1:
                    convertView = mInflater.inflate(R.layout.row_of_type_1, parent, false);
                    holder.text = (TextView) convertView.findViewById(R.id.textview_type_1);
                    break;
                case TYPE_2:
                    convertView = mInflater.inflate(R.layout.row_of_type_2, parent, false);
                    holder.text = (TextView) convertView.findViewById(R.id.textview_type_2);
                    break;
             }
             convertView.setTag(holder);
         } else {
             holder = (ViewHolder) convertView.getTag();
         }

         //get the text for that specific cell and set it
         holder.text.setText(getMyCustomTextForThisCell());

         return convertView;
    }
}

static class ViewHolder {     
    TextView text;
}

---

单细胞型

如果您只需要一种类型的单元格，其中包含一个文本视图，并希望在所有单元格中放置不同长度的文本，并且单元格会自动调整其高度，只需在您的 CustomAdapter

private final class CustomArrayAdapter extends ArrayAdapter<String> {
    //the fastest is to get the layout inflater once and not each time getView is called
    private LayoutInflater mInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    public CustomArrayAdapter(Context context, int resource, int textViewResourceId, String[] objects) {
        super(context, resource, textViewResourceId, objects);
    }

    ...

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;

        if (convertView == null) {
            holder = new ViewHolder();
            convertView = mInflater.inflate(R.layout.row_type, parent, false);
            holder.text = (TextView) convertView.findViewById(R.id.textview_in_your_row);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        //get the text for that specific cell and set it
        holder.text.setText(getMyCustomTextForThisCell());

        return convertView;
    }
}

static class ViewHolder {     
    TextView text;
}

---

单元格布局

在示例中，我给出的文件 row_type.xml（您的行的布局文件）应该如下所示：

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/textview_in_your_row"
    android:paddingLeft="6dp"
    android:paddingRight="6dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>

不要忘记android:layout_height="wrap_content"，否则单元格不会调整大小

---

旁白

此旁注没有讨论 OP 问题，但是如果人们因为标题中的 细胞回收 词而来到这里，他们可能会对我给出一个完整的回收示例这一事实感兴趣此处带有 EditText 的单元格

The content of EditText contained into a Android ListView isn't saved

Answer 2

这是我使用 Xamarin 解决它的方法。

public override View GetView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        int type = GetItemViewType(position);
        if (convertView == null)
        {
            holder = new ViewHolder();
            convertView = context.LayoutInflater.Inflate(Resource.Layout.my_row_layout, parent, false);
            holder.myTextView = FindViewById<TextView>(Resource.Id.viewRow);
            convertView.Tag = holder;
        }
        else 
        {
            holder = (ViewHolder)convertView.Tag;
            int heightWeWant = heights[type];
            if (holder.myTextView.Height != heightWeWant) //height we have isn't what we want
            {
                AbsListView.LayoutParams parms = new AbsListView.LayoutParams(LinearLayout.LayoutParams.MatchParent, heightWeWant); //Width, Height //resize the view to the height we want
                convertView.LayoutParameters = parms;
            }
            convertView.Tag = holder;
        }

        holder.myText = "Some text here";

        return convertView;
    }