[Android学习系列13]关于Gridview的一些事

用mvc的思想去理解 数据源，adapter，xxxView的关系，写代码就轻松多了

先写一个简单的gridview

第一版:只有图片

xml

public class ActivityMain extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

GridView gridView = (GridView)findViewById(R.id.gridView1);
gridView.setAdapter( new MyGridviewAdapter(this) );

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}

//拥有textview的string内容  和imageview的资源id
class IconInfo {
String text;
int imageid;
}

//一个混合了textview和imageview的类
class MixedView {
ImageView imgview;
TextView textview;
}

class MyGridviewAdapter extends BaseAdapter {

Context context;  //传入ActivityMain给adapter，创建view的时候要用到
LayoutInflater inflater;
List<IconInfo> iconInfoList;

//做一个数组存图表的id
int []imagesId = {R.drawable.icon1,R.drawable.icon2,R.drawable.icon3,
R.drawable.icon4,R.drawable.icon5,R.drawable.icon6,
R.drawable.icon7,R.drawable.icon8,R.drawable.icon9};
String []titles = {"标题1","标题2","标题3","标题4","标题5","标题6","标题7","标题8","标题9"};

MyGridviewAdapter(Context con) {

this.context = con;
inflater = LayoutInflater.from(context);

iconInfoList = new ArrayList<IconInfo>();
for(int i=0; i<imagesId.length; i++)
{
IconInfo iconInfo = new IconInfo();
iconInfo.imageid = imagesId[i];
iconInfo.text = titles[i];
iconInfoList.add(iconInfo);
}

}

@Override
public int getCount() {
return imagesId.length;
}

@Override
public Object getItem(int arg0) {
return arg0;
}

@Override
public long getItemId(int arg0) {
return arg0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

MixedView mixedView;
//用setTag() getTag()  来节约findViewById所消耗的性能
if( convertView == null )
{
convertView = inflater.inflate(R.layout.grid_one_item, null);
mixedView = new MixedView();
mixedView.imgview  = (ImageView)convertView.findViewById(R.id.grid_item_image);
mixedView.textview = (TextView)convertView.findViewById(R.id.grid_item_text);
convertView.setTag(mixedView);
}
else
{
mixedView = (MixedView)convertView.getTag();
}

mixedView.imgview.setImageResource( iconInfoList.get(position).imageid );
mixedView.textview.setText( iconInfoList.get(position).text );

return convertView;

}

}

}

View Code

个人粗俗地理解这两句(错了求指正):

convertView.setTag(mixedView); // 为convertView设定一个 指向mixedView的引用

mixedView= (MixedView) convertView.getTag(); // 把convertView所引用的对象赋给mixedView， 也就是说，convertView和mixedView引用的是同一个内存里的东西

//所以getview时 我们做处理的是mixedView，还可以返回convertView，因为他们引用的是同一个东西啊

最后长这样：



android:stretchMode 参考下图



更多参考:

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/article/6144664.html