Android GridView中选中图片时变大，而当焦点离开该图片后缩小

来源：互联网发布：充值软件多少钱编辑：程序博客网时间：2024/05/08 01:34

http://www.apkbus.com/forum.php?mod=viewthread&tid=69669

用Android实现的浏览器导航界面，如下图所示：

如上图所示的众多图片是用GridView实现的。而GridView使用的时候一般都要setAdapter(...)

GrideView.setAdapter(BaseAdatper)

一般都通过继承BaseAdapter来实现自己的Adapter。有一些必须实现的方法：

/ How many items are in the data set represented by this Adapter. public int getCount() { } // Get the data item associated with the specified position in the data set. public Object getItem(int position) { } // Get the row id associated with the specified position in the list. public long getItemId(int position) { } // Get a View that displays the data at the specified position in the data set. public View getView(int position, View convertView, ViewGroup parent) { }

为了使GridView里面的Item被选中的时候能够放大，而离开的时候又变回原来的大小，我也是煞费苦心，找了很多资料，最后在

http://my.oschina.net/u/126188/blog/28990。代码就是在adapter中加入

private int selected = -1; public void notifyDataSetChanged(int id) { selected = id; super.notifyDataSetChanged(); }

并在 getView中进行判断：

public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub MyImageButton imgBtn; imgBtn = new MyImageButton(this.context, photoLink[position]); if(selected == position) { // the special one.Scale Large imgBtn.setScaleType(ScaleType.CENTER_CROP); } else { // the rest.Scale small imgBtn.setScaleType(ScaleType.CENTER_INSIDE); } return (View)imgBtn; }

当我们的GridView设置了Adapter的时候，我们就可以设置OnItemSelectedListener了

zonesView.setOnItemSelectedListener(new OnItemSelectedListener() { public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { Log.d("zonesView", "onItemSelected"); ImageAdapter zonesImageAdapter = (ImageAdapter) zonesView.getAdapter(); zonesImageAdapter.notifyDataSetChanged(arg2); } public void onNothingSelected(AdapterView<?> arg0) { // TODO Auto-generated method stub } });

这样一来，当GrideView的Item被选中的时候就会放大，而其他未被选中的就会变小

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