Android GridView的使用方法

Android的GridView控件用于把一系列的空间组织成一个二维的网格显示出来 应用的比较多的就是组合图片显示 下面我就详细讲一个例子

首先写一个类继承BaseAdapter

[java] view plaincopy

public class ImageList extends BaseAdapter {



public Bitmap[] image;

Activity activity;



// construct

public ImageList(Activity a) {

activity = a;

}

@Override

public int getCount() {

// TODO Auto-generated method stub

return image.length;

}

@Override

public Object getItem(int position) {

// TODO Auto-generated method stub

return image[position];

}

@Override

public long getItemId(int position) {

// TODO Auto-generated method stub

return position;

}

public View getView(int position, View convertView, ViewGroup parent) {

// TODO Auto-generated method stub

ImageView imageView;

if (convertView == null) {

imageView = new ImageView(activity);

imageView.setLayoutParams(new GridView.LayoutParams(50, 50));// 设置ImageView宽高

imageView.setAdjustViewBounds(false);

imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);



} else {

imageView = (ImageView) convertView;

}

imageView.setImageBitmap(image[position]);



return imageView;

}

public static Bitmap drawableToBitmap(Drawable drawable) {



Bitmap bitmap = Bitmap

.createBitmap(

drawable.getIntrinsicWidth(),

drawable.getIntrinsicHeight(),

drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888

: Bitmap.Config.RGB_565);

Canvas canvas = new Canvas(bitmap);

drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());

drawable.draw(canvas);

return bitmap;

}

}

然后在主程序里

[c-sharp] view plaincopy

final GridView gv = (GridView) findViewById(R.id.grid);

ImageList adapter = new ImageList(available.this);

Resources res=getResources();

Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.logo);

adapter.image=new Bitmap[20];

for(int i=0;i<=19;i++)

{

adapter.image[i]=bmp;

}

gv.setAdapter(adapter);

gv.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> arg0, View arg1,

int arg2, long arg3) {

// TODO Auto-generated method stub

Log.i("phb", arg2 + "");

Log.i("phbsel",gv.isFocused()+"");

Intent i=new Intent(available.this, com.mobile.links.shop.mycx.shopcart.class);

startActivity(i);

}

});

gv.setOnItemSelectedListener(new OnItemSelectedListener(){

@Override

public void onItemSelected(AdapterView<?> arg0, View arg1,

int arg2, long arg3) {

// TODO Auto-generated method stub

Log.i("selected",arg2+"");

tv.setText(arg2+":detail");

}

@Override

public void onNothingSelected(AdapterView<?> arg0) {

// TODO Auto-generated method stub



}



});



其中onClick函数是判断被点击

而onSelect函数是判断被选中 也就是获得焦点的imageview

这样我们就可以基于gridview来做一些应用了。

构建gridview的xml代码

[c-sharp] view plaincopy

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

android:id="@+id/relativelayout"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

>

<GridView android:id="@+id/availgrid"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:numColumns="4"

android:verticalSpacing="30dp"

android:layout_centerHorizontal = "true"



/>





</LinearLayout>