Android开发之GridView的使用(解读谷歌官方API)
GridView将图片显示在二维可移动的网格里。使用ListAdapter能够将Grid项目自己主动填充满整个布局。
以下我们依据官方文档的样例来实现一下使用GridView,点击视图里的图片弹出图片的position的效果。
首先在main.xml文件创建下列布局。
<?
xml version="1.0" encoding="utf-8"?
> <GridView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/gridview" android:layout_width="fill_parent" android:layout_height="fill_parent" android:columnWidth="90dp" android:numColumns="auto_fit" android:verticalSpacing="10dp" android:horizontalSpacing="10dp" android:stretchMode="columnWidth" android:gravity="center" />
在MainAcitivity中,由于要使用setAdapter适配器载入数据。所以要先创建一个类继承BaseAdapter
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));
gridview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
Toast.makeText(HelloGridView.this, "" + position, Toast.LENGTH_SHORT).show();
}
});
}
public class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) { // if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
return imageView;
}
// references to our images
private Integer[] mThumbIds = {
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7
};
}
加入以上代码就已大功告成。
setLayoutParams(ViewGroup.LayoutParams)
,设置图片大小。setScaleType(ImageView.ScaleType)
设置图片显示形式。setPadding(int, int, int, int)
设置图片的间距。假设视图传递给getView()不是null,那么使用当地的回收的convertView视图对象进行初始化。posted on 2019-04-24 10:02 xfgnongmin 阅读(116) 评论(0) 编辑 收藏 举报