android实现多列显示的下拉列表框-Spinner

严格来说，这并不是一个下拉列表，只不过实现的效果很像是下拉列表

实现原理：

该下拉列表其实是一个AlertDialog.Builder，给它设置了一个以LinearLayout布局的View。该View内使用了一个GridView组件，

代码：

[java] view plaincopyprint?

1. package yyy.testandroid9; 
2.     private Intent intent; 
3.     private int index =0; 
4.     private SharedPreferences preferences; 
5.     private File file; 
6.     private Spinner spinner; 
7.     private GridView gridView; 
8.     private LinearLayout layout; 
9.     private Builder builder; 
10.     private AlertDialog dialog; 
11.     private MyAdapter adapter; 
12.  
13.     /** Called when the activity is first created. */ 
14.     @Override 
15.     public void onCreate(Bundle savedInstanceState) { 
16.         super.onCreate(savedInstanceState); 
17.         setContentView(R.layout.main); 
18.  
19.         LayoutInflater inflater = LayoutInflater.from(this); 
20.         layout = (LinearLayout) inflater.inflate(R.layout.bank_grid, null); 
21.         gridView = (GridView) layout.findViewById(R.id.grid); 
22.         adapter = new MyAdapter(this); 
23.         gridView.setAdapter(adapter); 
24.         button1 = (Button) findViewById(R.id.button1); 
25.         button2 = (Button) findViewById(R.id.button2); 
26.         textView = (TextView) findViewById(R.id.textview); 
27.         builder = new Builder(TestAndroid9Activity.this); 
28.         builder.setView(layout); 
29.          
30.          
31.         button1.setOnClickListener(new OnClickListener() { 
32.             public void onClick(View arg0) { 
33.                 // TODO Auto-generated method stub 
34.                  if(dialog == null){ 
35.                      dialog = builder.show(); 
36.                  } 
37.                  dialog.show(); 
38.                   
39.             } 
40.         }); 
41.          
42.          
43.         gridView.setOnItemClickListener(new OnItemClickListener() { 
44.             public void onItemClick(AdapterView<?> arg0, View arg1,int position, 
45.                     long arg3) { 
46.                 // TODO Auto-generated method stub 
47.                 button1.setText(getResources().getStringArray(R.array.city)[position]); 
48.                 dialog.dismiss(); 
49.                 adapter.map.put(index, false); 
50.                 adapter.map.put(position, true); 
51.                 index = position; 
52.                 adapter.notifyDataSetChanged(); 
53.             } 
54.         }); 
55.          
56.     } 
57.  
58.     private class MyAdapterextends BaseAdapter{ 
59.         private Context context; 
60.         private String[] citys; 
61.         private LayoutInflater inflater; 
62.         public HashMap<Integer, Boolean> map; 
63.          
64.         public MyAdapter(Context context) { 
65.             super(); 
66.             this.context = context; 
67.             citys = context.getResources().getStringArray(R.array.city); 
68.             inflater = LayoutInflater.from(context); 
69.             map = new HashMap<Integer, Boolean>(); 
70.             for(int i=0;i<citys.length;i++){ 
71.                 map.put(i, false); 
72.             } 
73.         } 
74.  
75.         public int getCount() { 
76.             // TODO Auto-generated method stub 
77.             return citys.length; 
78.         } 
79.  
80.         public Object getItem(int position) { 
81.             // TODO Auto-generated method stub 
82.             return null; 
83.         } 
84.  
85.         public long getItemId(int position) { 
86.             // TODO Auto-generated method stub 
87.             return position; 
88.         } 
89.  
90.         public View getView(int position, View view, ViewGroup parent) { 
91.             // TODO Auto-generated method stub 
92.             if(view == null){ 
93.                 view = inflater.inflate(R.layout.bank_item,null); 
94.             } 
95.             TextView textView = (TextView) view.findViewById(R.id.list_text); 
96. RadioButton radioButton = (RadioButton) view.findViewById(R.id.radiobutton);
97.             radioButton.setChecked(map.get(position)); 
98.             textView.setText(citys[position]); 
99.             return view; 
100.         } 
101.     } 

package yyy.testandroid9;private Intent intent;private int index = 0;private SharedPreferences preferences;private File file;private Spinner spinner;private GridView gridView;private LinearLayout layout;private Builder builder;private AlertDialog dialog;private MyAdapter adapter;/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);LayoutInflater inflater = LayoutInflater.from(this);layout = (LinearLayout) inflater.inflate(R.layout.bank_grid, null);gridView = (GridView) layout.findViewById(R.id.grid);adapter = new MyAdapter(this);gridView.setAdapter(adapter);button1 = (Button) findViewById(R.id.button1);button2 = (Button) findViewById(R.id.button2);textView = (TextView) findViewById(R.id.textview);builder = new Builder(TestAndroid9Activity.this);builder.setView(layout);    button1.setOnClickListener(new OnClickListener() {public void onClick(View arg0) {// TODO Auto-generated method stub if(dialog == null){ dialog = builder.show(); } dialog.show(); }});gridView.setOnItemClickListener(new OnItemClickListener() {public void onItemClick(AdapterView<?> arg0, View arg1, int position,long arg3) {// TODO Auto-generated method stubbutton1.setText(getResources().getStringArray(R.array.city)[position]);dialog.dismiss();adapter.map.put(index, false);adapter.map.put(position, true);index = position;adapter.notifyDataSetChanged();}});}private class MyAdapter extends BaseAdapter{private Context context;private String[] citys;private LayoutInflater inflater;        public HashMap<Integer, Boolean> map;public MyAdapter(Context context) {super();this.context = context;citys = context.getResources().getStringArray(R.array.city);inflater = LayoutInflater.from(context);map = new HashMap<Integer, Boolean>();for(int i=0;i<citys.length;i++){map.put(i, false);}}public int getCount() {// TODO Auto-generated method stubreturn citys.length;}public Object getItem(int position) {// TODO Auto-generated method stubreturn null;}public long getItemId(int position) {// TODO Auto-generated method stubreturn position;}public View getView(int position, View view, ViewGroup parent) {// TODO Auto-generated method stubif(view == null){view = inflater.inflate(R.layout.bank_item, null);}TextView textView = (TextView) view.findViewById(R.id.list_text);RadioButton radioButton = (RadioButton) view.findViewById(R.id.radiobutton);radioButton.setChecked(map.get(position));textView.setText(citys[position]);return view;}}

bank_grid.xml

[java] view plaincopyprint?

1. <?xml version="1.0" encoding="utf-8"?> 
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
3.     android:layout_width="fill_parent" 
4.     android:layout_height="fill_parent" 
5.     android:orientation="vertical" 
6.     android:padding="20dp"  
7.     android:background="#ffffff" 
8.     android:id="@+id/grid_layout"> 
9.  
10.      
11.       
12.     <GridView     
13.         android:id="@+id/grid" 
14.             android:layout_width="fill_parent" 
15.             android:layout_height="fill_parent" 
16.             android:verticalSpacing="20px" 
17.             android:horizontalSpacing="10px" 
18.             android:numColumns="4" 
19.             android:scrollbars="vertical" 
20.             android:layout_margin="10dp"/> 
21.      
22. </LinearLayout> 

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical"    android:padding="20dp"     android:background="#ffffff"    android:id="@+id/grid_layout"> <GridView    android:id="@+id/grid"  android:layout_width="fill_parent"android:layout_height="fill_parent"android:verticalSpacing="20px"android:horizontalSpacing="10px"android:numColumns="4"android:scrollbars="vertical"android:layout_margin="10dp"/></LinearLayout>

bank_item.xml

[java] view plaincopyprint?

1. <?xml version="1.0" encoding="utf-8"?> 
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
3.     android:layout_width="fill_parent" 
4.     android:layout_height="fill_parent" 
5.     android:background="#ffffff" 
6.      > 
7.  
8.      <RadioButton 
9.         android:id="@+id/radiobutton" 
10.         android:layout_width="wrap_content" 
11.         android:layout_height="wrap_content" 
12.         android:layout_marginRight="15dp" 
13.         android:focusable="false" 
14.         android:clickable="false" 
15.         android:focusableInTouchMode="false" 
16.         /> 
17.     <TextView 
18.         android:id="@+id/list_text" 
19.         android:layout_width="wrap_content" 
20.         android:layout_height="wrap_content" 
21.         android:textColor="#000000"  
22.         android:layout_gravity="center_vertical"/> 
23.  
24. </LinearLayout>