android - 如何在 ListView 适配器类中实现 2 种不同类型的分隔符(即标题)

Question

我通过这组代码调用适配器:

mAdapter = new MyCustomAdapter(getActivity());

mAdapter.addSeparatorItem(new ContentWrapper(q.get(0).getA_name(),null));
mAdapter.addItem(new ContentWrapper(q.get(0).getAS_name(), q.get(0).getDesc_art()));

考虑这段代码:

private class MyCustomAdapter extends BaseAdapter {

private static final int TYPE_ITEM = 0;
private static final int TYPE_SEPARATOR = 1;
private static final int TYPE_MAX_COUNT = TYPE_SEPARATOR + 1;

private ArrayList<ContentWrapper> mData = new ArrayList<ContentWrapper>();
private LayoutInflater mInflater;

private TreeSet<Integer> mSeparatorsSet = new TreeSet<Integer>();

public MyCustomAdapter(Context context)
{
    mInflater = LayoutInflater.from(context); 
}

public void addItem(ContentWrapper value) {
    mData.add(value);
    notifyDataSetChanged();
}

public void addSeparatorItem(ContentWrapper value) {
    mData.add(value);
    // save separator position
    mSeparatorsSet.add(mData.size() - 1);
    notifyDataSetChanged();
}

public ContentWrapper getItem(int position) {
    return mData.get(position);
}
@Override
public int getItemViewType(int position) {
    return mSeparatorsSet.contains(position) ? TYPE_SEPARATOR : TYPE_ITEM;
}

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

public int getCount() {
    return mData.size();
}

public long getItemId(int position) {
    Log.v("getItemId Position", ""+position);
    return position;

}

public View getView(final int position, View convertView, ViewGroup parent) {
    ViewHolder holder = null;
    int type = getItemViewType(position);
    if (convertView == null) {
        holder = new ViewHolder();
        switch (type) {
        case TYPE_ITEM:
            convertView = mInflater.inflate(R.layout.white, null);
            holder.textView = (TextView)convertView.findViewById(R.id.text);
            break;
        case TYPE_SEPARATOR:
            convertView = mInflater.inflate(R.layout.black, null);
            holder.textView = (TextView)convertView.findViewById(R.id.textSeparator);
            count++;
            break;
        }
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder)convertView.getTag();
    } holder.textView.setText(mData.get(position).getItem());

    if (type == TYPE_ITEM) {
        holder.textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
                    builder.setIcon(R.drawable.ic_launcher);
                    final String title = mData.get(position).getItem();
                    builder.setTitle(title);
                    builder.setMessage(mData.get(position).getItemDescription());
                    builder.setCancelable(false);
                    builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    });
                    AlertDialog alertDialog = builder.create();
                    alertDialog.setOnShowListener(new DialogInterface.OnShowListener() {
                        @Override
                        public void onShow(DialogInterface dialog) {
                            AlertDialog alertDialog = (AlertDialog) dialog;
                            ViewGroup viewGroup = (ViewGroup) alertDialog.getWindow()
                                    .getDecorView();
                            TextView textView = findTextViewWithTitle(viewGroup, title);
                            if (textView != null) {
                                textView.setEllipsize(null);
                                textView.setMaxHeight((int) (100 * alertDialog.getContext().getResources().getDisplayMetrics().density)); 
                                textView.setMovementMethod(new ScrollingMovementMethod());
                            }
                        }
                    });
                    alertDialog.show();
                }

                private TextView findTextViewWithTitle(ViewGroup viewGroup, String title) {
                    for (int i = 0, N = viewGroup.getChildCount(); i < N; i++) {
                        View child = viewGroup.getChildAt(i);
                        if (child instanceof TextView) {
                            TextView textView = (TextView) child;
                            if (textView.getText().equals(title)) {
                                return textView;
                            }
                        } else if (child instanceof ViewGroup) {
                            ViewGroup vGroup = (ViewGroup) child;
                            return findTextViewWithTitle(vGroup, title);
                        }
                    }
                    return null;
                }
            });
    } else {
        holder.textView.setOnClickListener(null);
    }

return convertView;
}
}
public static class ViewHolder {
public TextView textView;
}

public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
return false;
}

此代码仅在 AlertDialog 中显示所选项目(此处为 TYPE_ITEM)的描述。

如您所见，TYPE_SEPERATOR 已禁用 onClick()，我想再添加一个 TYPE_SEPERATOR_GRAY(来自 gray.xml)是禁用 onClick() 的另一种类型分隔符。

我是否需要再添加一种类似于 addSeparatorItem(ContentWrapper value) 的方法，例如 addSeparatorItemGray(ContentWrapper value)。我知道我必须在 getView() 的开关中再添加一个案例来膨胀 gray.xml

或者我还应该添加/修改什么？

编辑:ContentWrapper 包含项目文本及其描述。我实现了 ContentWrapper 来为每个 TYPE_ITEM 分配一个描述

public class ContentWrapper {

private String mItem, mItemDescription;

public ContentWrapper(String item, String itemDescription) {
    mItem = item;
    mItemDescription = itemDescription;
}

public String getItem() {
    return mItem;
}

public String getItemDescription() {
    return mItemDescription;
}
}

mAdapter 是 MyCustomAdapter 类型。

我的问题的前 3-4 行说 addSeparatorItem 没有任何描述，所以在第二个参数中传递了 null & addItem 有两个文本，描述。

我想在列表中的某些指定位置手动添加另一个 TYPE_GRAY_SEPARATOR ，例如:

 mAdapter.addSeparatorItemGray("HI after 1st view");
 mAdapter.addSeparatorItemGray("HI after 23rd view");
 mAdapter.addSeparatorItemGray("HI after 45 view");

Answer 1

getViewType 方法应返回 3(列表项 + 分隔符 + 灰色分隔符)。因此将 TYPE_MAX_COUNT 设置为 3。

private static final int TYPE_GRAY_SEPARATOR = 2;
private static final int TYPE_MAX_COUNT = TYPE_GRAY_SEPARATOR + 1;

保存灰色分隔符位置的数据结构:

private TreeSet<Integer> mGraySeparatorsSet = new TreeSet<Integer>();

添加灰色分隔符的方法。

public void addGraySeparatorItem(ContentWrapper value) {
    mData.add(value);
    // save separator position
    mGraySeparatorsSet.add(mData.size() - 1);
    notifyDataSetChanged();
}           

getItemViewType 方法应该根据位置返回适当的 View 。

@Override
public int getItemViewType(int position) {
    int viewType = TYPE_ITEM;
    if(mSeparatorSet.contains(position))
       viewType = TYPE_SEPARATOR;
    else if(mGraySeparatorSet.contains(position)) {
       viewType = TYPE_GRAY_SEPARATOR; 
    }
    return viewType;
}

getView 方法应该处理 TYPE_GRAY_SEPARATOR:

public View getView(final int position, View convertView, ViewGroup parent) {
    // Existing code
    switch(type) {
        // Existing cases
        case TYPE_GRAY_SEPARATOR: 
           // Inflate appropriate view
           break;
    }
    // Existing code
}