标签：
GridView: A view that shows items in two-dimensional scrolling grid. The items in the grid come from the ListAdapter associated with this view. 简单说，GridView就是我们资源管理器平常见到的一个个文件的icon显示方式。
@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.grid_2); GridView g = (GridView) findViewById(R.id.myGrid); g.setAdapter(new ImageAdapter(this)); }
而ImageAdapter一般是extends BaseAdapter。BaseAdapter是implements ListAdapter SpinnerAdapter，但很多时候自定义的Adapter都是override ListAdapter的父类Adapter接口里面的方法：
public class ImageAdapter extends BaseAdapter { public ImageAdapter(Context c) { mContext = c; } public int getCount() { return mThumbIds.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { ImageView imageView; if (convertView == null) { imageView = new ImageView(mContext); imageView.setLayoutParams(new GridView.LayoutParams(45, 45));//设置ImageView宽高 imageView.setAdjustViewBounds(false); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setPadding(8, 8, 8, 8); } else { imageView = (ImageView) convertView; } imageView.setImageResource(mThumbIds[position]); return imageView; } private Context mContext; private Integer[] mThumbIds = { R.drawable.sample_thumb_0, R.drawable.sample_thumb_1, R.drawable.sample_thumb_2, R.drawable.sample_thumb_3, R.drawable.sample_thumb_4, R.drawable.sample_thumb_5, R.drawable.sample_thumb_6, R.drawable.sample_thumb_7 }; }
<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/myGrid"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:numColumns="auto_fit"
android:columnWidth="60dp"
android:stretchMode="columnWidth"
android:gravity="center"
/>
可以看到getView，和ImageView是重点，影响图片的显示效果。而且发现列数是不确定的，取决于每个ImageView的宽度和屏幕的宽度。接下来看看ImageView。
//获得Bitmap的高和宽 int bmpWidth=bmp.getWidth(); int bmpHeight=bmp.getHeight(); //设置缩小比例 double scale=0.8; //计算出这次要缩小的比例 scaleWidth=(float)(scaleWidth*scale); scaleHeight=(float)(scaleHeight*scale); //产生resize后的Bitmap对象 Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true);
** 要注意一点，我发现Drawable文件夹里面的图片命名是不能大写的。
Android UI学习 - GridView和ImageView的使用
标签：
原文地址：http://www.cnblogs.com/samjustin/p/4650491.html
