Android网格布局GridView学习使用

<?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:numColumns="auto_fit"  android:verticalSpacing="10dp"  android:horizontalSpacing="10dp"  android:columnWidth="90dp"  android:stretchMode="columnWidth"  android:gravity="center" /> 

package com.yarin.android.Examples_04_19;  import android.content.Context; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.ImageView;  public class ImageAdapter extends BaseAdapter {  // 定义Context  private Context  mContext;  // 定义整型数组 即图片源  private Integer[] mImageIds =  {    R.drawable.img_1,    R.drawable.img_2,    R.drawable.img_3,    R.drawable.img_4,    R.drawable.img_5,    R.drawable.img_6,    R.drawable.img_7,    R.drawable.img_8,    R.drawable.img_1,  };   public ImageAdapter(Context c)  {   mContext = c;  }   // 获取图片的个数，从而知道需要加载的Item的数目与getView（）配合循环加载  public int getCount()  {   return mImageIds.length;  }   // 获取图片在库中的位置  public Object getItem(int position)  {   return position;  }    // 获取图片ID  public long getItemId(int position)  {   return position;  }    public View getView(int position, View convertView, ViewGroup parent)  {   ImageView imageView;   if (convertView == null)   {    // Item没有被加载过，给ImageView设置资源    imageView = new ImageView(mContext);    // 设置布局 图片60*60显示    imageView.setLayoutParams(new GridView.LayoutParams(65, 65));    // 设置显示比例类型    imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);   }   else   {    //Item已经被加载过，直接返回convertView    imageView = (ImageView) convertView;   }    imageView.setImageResource(mImageIds[position]);   return imageView;  }  } 

package com.yarin.android.Examples_04_19;  import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.GridView; import android.widget.Toast; import android.widget.AdapterView.OnItemClickListener;  public class Activity01 extends Activity {    @Override  public void onCreate(Bundle savedInstanceState)  {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);    //取得GridView对象   GridView gridview = (GridView) findViewById(R.id.gridview);   //添加元素给gridview   gridview.setAdapter(new ImageAdapter(this));    // 设置GridView的背景   gridview.setBackgroundResource(R.drawable.bg0);    //事件监听   gridview.setOnItemClickListener(new OnItemClickListener() {    public void onItemClick(AdapterView<?> parent, View v, int position, long id)    {     Toast.makeText(Activity01.this, "你选择了" + (position + 1) + " 号图片", Toast.LENGTH_SHORT).show();    }   });  } }