GridView的基本使用

***GridView的基本使用

*定义：
GridView是一个表格显示资源的控件，可以在两个可滚动的方向上显示资源

*基本属性：
android:numColumns="auto_fit" ：表示GridView中一行中展示item的列数，auto_fit表示根据手机屏幕的宽度由系统设置比较理想的列数，当然这里也可以指定具体列数
android:columnWidth="80dp" :设置每一列的宽度
android:horizontalSpacing="10dp" : 表示设置列之间的间距
android:verticalSpacing="10dp" :表示设置行之间的间距

*基本使用：和ListView的使用类似

xml布局中：

 <ImageView
    android:id="@+id/imageView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/timg1" />

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="TextView" />

Java代码中：

public class ResultActivity extends Activity {
	private GridView gv;
	private List<Map<String, Object>> list;
	private int[] images = {R.drawable.timg1,R.drawable.timg2,R.drawable.timg3,R.drawable.timg4,R.drawable.timg5,R.drawable.timg6};
	//要注意几张图片的大小相同
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_result);
		
		gv = (GridView) findViewById(R.id.gv);
		list = new ArrayList<Map<String,Object>>();
		for (int i = 0; i < images.length; i++) {
			Map<String, Object> map = new HashMap<String, Object>();
			map.put("img", images[i]);
			map.put("text", "头像-"+i);
			list.add(map);
		}
		MyBaseAdapter adapter = new MyBaseAdapter();
		gv.setAdapter(adapter);
	}
	
	class MyBaseAdapter extends BaseAdapter{

		@Override
		public int getCount() {
			return list.size();
		}

		@Override
		public Object getItem(int position) {
			return list.get(position);
		}

		@Override
		public long getItemId(int position) {
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder holder = null;
			if(convertView == null){
				LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
				convertView = inflater.inflate(R.layout.grid_item, null);
				holder = new ViewHolder();
				holder.iv = (ImageView) convertView.findViewById(R.id.imageView1);
				holder.tv = (TextView) convertView.findViewById(R.id.textView1);
				convertView.setTag(holder);
			}else{
				holder = (ViewHolder) convertView.getTag();
			}
			holder.iv.setImageResource((Integer) list.get(position).get("img"));
			holder.tv.setText((CharSequence) list.get(position).get("text"));
			return convertView;
		}
		
	}
	static class ViewHolder{
		ImageView iv;
		TextView tv;
	}
}