Spinner 两种效果

最新推荐文章于 2021-06-07 12:07:05 发布

原创最新推荐文章于 2021-06-07 12:07:05 发布 · 762 阅读

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本文介绍如何在Android应用中使用自定义适配器解决Spinner组件标题与下拉列表内容不一致的问题，通过创建CustomSpinnerAdapter实现标题和下拉选项内容差异化显示。

作为下拉选项列表，还是非常不错且易用的，同时也存在一些局限性，比如：标题栏、下拉栏、显示内容必须一致，这使得其实用性大打折扣。

1. 先说说其不足之处即：标题下拉显示内容相同问题：

* 定义待显示内容以TextView为例：

String[] content = { "eoe.android","eoe.mobile","eoe.mark","eoe.rd","eoe.mobile" };

* 定义 CustomAdapter :

public class CustomAdapter extends BaseAdapter { Activity activity; public CustomAdapter(Activity a){ activity = a; } @Override public int getCount() { // TODO Auto-generated method stub return content.length; } @Override public Object getItem(int position) { // TODO Auto-generated method stub return position; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub TextView tv = new TextView(activity); tv.setText(content[position]); tv.setTextSize(20); return tv; } }

* emulator 运行效果可以看出：标题、下拉、显示内容是一样的；。

2. 使得标题下拉二者显示内容不同

* 定义标题显示内容:title 下拉继续使用上面定义的content

String[] title = { "0","1","2","3","4","5" };

* 定义 CustomSpinnerAdapter:

public class CustomSpinnerAdapter implements SpinnerAdapter { Activity activity; public CustomSpinnerAdapter(Activity a){ activity = a; } @Override public View getDropDownView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub TextView tv = new TextView(activity); tv.setText(content[position]); tv.setTextSize(20); tv.setTextColor(Color.RED); return tv; } @Override public int getCount() { // TODO Auto-generated method stub return content.length; } @Override public Object getItem(int position) { // TODO Auto-generated method stub return position; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public int getItemViewType(int position) { // TODO Auto-generated method stub return IGNORE_ITEM_VIEW_TYPE; } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub TextView tv = new TextView(activity); tv.setText(title[position]); tv.setTextColor(Color.GREEN); return tv; } @Override public int getViewTypeCount() { // TODO Auto-generated method stub return content.length; } @Override public boolean hasStableIds() { // TODO Auto-generated method stub return false; } @Override public boolean isEmpty() { // TODO Auto-generated method stub return false; } @Override public void registerDataSetObserver(DataSetObserver observer) { // TODO Auto-generated method stub } @Override public void unregisterDataSetObserver(DataSetObserver observer) { // TODO Auto-generated method stub } }

* emulator 运行截图注意二者的不同显示：