GridView是类似于ListView的控件,只是GridView可以使用多个列来呈现内容,而ListView是以行为单位,所以用法上是差不多的。
主布局文件,因为要做下拉刷新,所以加了一个ProgressBar,GridView的numColumns属性是指每一行有多少列
每个Item的布局文件,这里比较简单的一张图片加一段文字
主活动代码:
public class MainActivity extends Activity {
private GridView gv;
private ProgressBar pb;
private List
解析:
在onCreate方法中先获取两个组件,然后把progressBar设置为隐藏,下拉的时候再显示,刷新完毕再隐藏。然后为GridView设置数据源,这里方便起见用SimpleAdapter,然后给GridView设置ontouchListener,并在onTouch方法中把触摸事件交给我们自定义的GestureDetector对象来处理,在GestureDetector的onFling方法中处理下拉事件,在里面判断是否下拉以及GridView是否在最顶端,如果是,显示progressBar控件并开一个线程来处理刷新,这里做模拟就睡眠2000毫秒,最后用message对象返回一个消息给Handler,Handler在主线程中更新GridView。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pb = (ProgressBar) findViewById(R.id.pb);
gv = (GridView) findViewById(R.id.gv);
pb.setVisibility(View.GONE);
initData();
adapter = new SimpleAdapter(this, list, R.layout.item_layout,
new String[] { "image", "text" }, new int[] { R.id.item_iv,
R.id.item_tv });
gv.setAdapter(adapter);
gsDetector = new GestureDetector(this, new Mlistener());
gv.setonTouchListener(new onTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
// Log.e("MainActivity", event.getX()+"");
return gsDetector.onTouchEvent(event);
}
});
}
class Mlistener implements onGestureListener {
@Override
public boolean onDown(MotionEvent e) {
return false;
}
@Override
public void onShowPress(MotionEvent e) {
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
return false;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
return false;
}
@Override
public void onLongPress(MotionEvent e) {
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (e2.getY() - e1.getY() > 0 && gv.getFirstVisiblePosition() == 0) {
pb.setVisibility(View.VISIBLE);
Animation animation = new ScaleAnimation(1f, 1f, 0, 1f);
animation.setDuration(300);
pb.startAnimation(animation);
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(2000);
Message msg = new Message();
msg.what = 1;
handler.sendMessage(msg);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
}
return false;
}
}
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持考高分网。



