Android入门之GridView（纯java）

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class GridViewTest extends Activity {

private GridView gv=null;

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
gv_init();
setContentView(gv);
}

/*gv初始化*/
void gv_init(){
gv=new GridView(this);
GridView.LayoutParams lp=new GridView.LayoutParams(-1,-1);
gv.setLayoutParams(lp);
gv.setColumnWidth(90);
gv.setNumColumns(GridView.AUTO_FIT);
gv.setVerticalSpacing(10);
gv.setHorizontalSpacing(10);
gv.setAdapter(new ImageAdapter(this));
}

/*ImageAdapter*/
public class ImageAdapter extends BaseAdapter {

private Context context;
//图片源数组
private Integer[] imageInteger = {R.drawable.p00,R.drawable.p01,
R.drawable.p02,R.drawable.p03,
R.drawable.p04,R.drawable.p05,
R.drawable.p06,R.drawable.p07,
R.drawable.p08,R.drawable.p09,
R.drawable.p10,R.drawable.p11,
R.drawable.p12,R.drawable.p13,
R.drawable.p14,R.drawable.p15,
R.drawable.p16,R.drawable.p17,
R.drawable.p18,R.drawable.p19
};

public ImageAdapter(Context c) {
context = c;
}

public int getCount() {
return imageInteger.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 = new ImageView(context);
imageView.setLayoutParams(new GridView.LayoutParams(90,-2));
/*图片缩放处理，如果先设置了iamgeView的大小，则必须注意加载的图片大小不能超出，否则无法显示*/
Bitmap bm = BitmapFactory.decodeResource(context.getResources(),imageInteger[position]);
//原始尺寸
int width=bm.getWidth();
int height=bm.getHeight();
//缩放比例
if(width>90){
float scaleWidth=((float)90)/width;
float scaleHeight=scaleWidth;
// 创建操作图片用的matrix对象
Matrix matrix = new Matrix();
// 缩放图片动作
matrix.postScale(scaleWidth, scaleHeight);
//旋转图片 动作
//matrix.postRotate(45);
// 创建新的图片
Bitmap resizedBitmap = Bitmap.createBitmap(bm,0,0,width, height,matrix,true);
imageView.setImageBitmap(resizedBitmap);
}else{
imageView.setImageBitmap(bm);
}
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
return imageView;
}
}
}