一、GridView
1、简述
GridView按照行列来显示图片或文本的一种视图，排列其实有点类似TableLayout布局，
不过和TableLayout还是差别很大的,倒比较像二维的ListView。位于android.widget包下，常常用来实现类似九宫格的图像。
实现手法和ListView有点相似，用Apapter把数据绑定到控件上，为容器提供子视图，利用视图的数据和元数据来构建每个子视图自定义Adapter显示。
如果需要自定义适配器 可以扩展抽象类BaseAdapter。
2、常用属性和对应方法如下：
下面用实例化SimpleAdapter和继承抽象类BaseAdapter方法实现下图的例子：
3、实例化SimpleAdapter实现
Activity代码：
private GridView gv;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.gridview); //准备要添加的数据条目
List<Map<String, Object>> items = new ArrayList<Map<String,Object>>();
for (int i = 0; i < 9; i++) {
Map<String, Object> item = new HashMap<String, Object>();
item.put("imageItem", R.drawable.ic_launcher);//添加图像资源的ID
item.put("textItem", "icon" + i);//按序号添加ItemText
items.add(item);
} //实例化SimpleAdapter适配器
SimpleAdapter adapter = new SimpleAdapter(this,
items,
R.layout.grid_item,
new String[]{"imageItem", "textItem"},
new int[]{R.id.image_item, R.id.text_item}); //获得GridView实例
gv = (GridView)findViewById(R.id.mygridview);
//为GridView设置适配器
gv.setAdapter(adapter); }
单个组件XML:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/RelativeLayout1"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:paddingBottom="6dip"
>
<ImageView
android:id="@+id/image_item"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:src="@drawable/ic_launcher"
/>
<TextView
android:id="@+id/text_item"
android:layout_below="@+id/image_item"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_centerHorizontal="true"
/>
</RelativeLayout>
页面主布局XML：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<GridView
android:id="@+id/mygridview"
android:numColumns="3"
android:gravity="center_horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:stretchMode="columnWidth"
/>
</LinearLayout>
4、继承抽象类BaseAdapter实现
替换成自己GridAdapter代码：
// //准备要添加的数据条目
// List<Map<String, Object>> items = new ArrayList<Map<String,Object>>();
// for (int i = 0; i < 9; i++) {
// Map<String, Object> item = new HashMap<String, Object>();
// item.put("imageItem", R.drawable.ic_launcher);//添加图像资源的ID
// item.put("textItem", "icon" + i);//按序号添加ItemText
// items.add(item);
// }
//
// //实例化SimpleAdapter适配器
// SimpleAdapter adapter = new SimpleAdapter(this,
// items,
// R.layout.grid_item,
// new String[]{"imageItem", "textItem"},
// new int[]{R.id.image_item, R.id.text_item}); List<GridInfo> list = new ArrayList<GridInfo>();
for (int i = 0; i < 9; i++) {
list.add(new GridInfo("icon"+i));
} GridAdapter adapter = new GridAdapter(this);
adapter.setList(list);
补上GridAdapter代码：
public class GridAdapter extends BaseAdapter {
private class GridHolder {
ImageView appImage;
TextView appName;
}
private Context context;
private List<GridInfo> list;
private LayoutInflater mInflater;
public GridAdapter(Context c) {
super();
this.context = c;
}
public void setList(List<GridInfo> list) {
this.list = list;
mInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
@Override
public Object getItem(int index) {
return list.get(index);
}
@Override
public long getItemId(int index) {
return index;
}
@Override
public View getView(int index, View convertView, ViewGroup parent) {
GridHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.grid_item, null);
holder = new GridHolder();
holder.appImage = (ImageView)convertView.findViewById(R.id.image_item);
holder.appName = (TextView)convertView.findViewById(R.id.text_item);
convertView.setTag(holder);
}else{
holder = (GridHolder) convertView.getTag();
}
GridInfo info = list.get(index);
if (info != null) {
holder.appName.setText(info.getName());
}
return convertView;
}
}
比较麻烦还是重写getView()方法。里面的GridInfo只是普通的JAVA bean类。