andriod GridView

<?xml version="1.0" encoding="UTF-8"?>
<GridView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/grid_view"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:columnWidth="90dp"
    android:gravity="center"
    android:horizontalSpacing="10dp"
    android:numColumns="auto_fit"
    android:stretchMode="columnWidth"
    android:verticalSpacing="10dp">

</GridView>

package com.example.yanlei.mytk;

import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setTitle("网络视图控件GridView！");

        GridView gridView=(GridView)findViewById(R.id.grid_view);
        gridView.setAdapter(new ImageAdapter(this));

    }

    public class ImageAdapter extends BaseAdapter{

        private Context mContext;
        public ImageAdapter(Context context){
            mContext=context;
        }
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return mImageIds.length;
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView imageView;
            if(convertView==null){
                imageView=new ImageView(mContext);
                imageView.setLayoutParams(new GridView.LayoutParams(85,85));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(8, 8, 8, 8);
            }else{
                imageView=(ImageView)convertView;
            }
            imageView.setImageResource(mImageIds[position]);
            return imageView;
        }

    }

    private Integer[] mImageIds = {
            R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2,
            R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,R.drawable.sample_8,
            R.drawable.sample_9,R.drawable.sample_10,R.drawable.sample_11};

}