Android开发之GridView的使用（解读谷歌官方API）

来源：互联网发布：卡盟源码下载编辑：程序博客网时间：2024/05/18 10:20

GridView将图片显示在二维可移动的网格里，使用ListAdapter可以将Grid项目自动填充满整个布局。下面我们根据官方文档的例子来实现一下使用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，因为要使用setAdapter适配器加载数据，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    };}

添加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。如果视图传递给getView()不是null,那么使用当地的回收的convertView视图对象进行初始化。

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