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;
    	}
    }
}