android开发入门----HelloGridView编译出错问题解决

         在学习android的过程中，发现HelloGridView这个类拷贝了网上的代码后编译不过，现在记录下我的解决方法，供需要的人参考。

报错的主要原因是import的package少了，解决办法是把鼠标移动到有错的单词上，会弹出一个pop框，上面列举了一些解决办法，选第一个就是import合适的package了，简单吧？有时还用最后一项“Fix project setup...”， 这样基本就ok了。

为了方便，下面附上HelloGridViewActivity.java源代码：

package com.example.HelloGridView;import android.app.Activity;import android.os.Bundle;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.GridView;import android.widget.Toast;import android.view.View;public class HelloGridViewActivity extends Activity {    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        GridView gridview = (GridView) findViewById(R.id.gridview);        gridview.setAdapter(new ImageAdapter(this));        gridview.setOnItemClickListener(new OnItemClickListener() {            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {                Toast.makeText(HelloGridViewActivity.this, "A " + position, Toast.LENGTH_SHORT).show();            }        });    }}

ImageAdapter.java的源代码：

package com.example.HelloGridView;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 {    private Context mContext;    public ImageAdapter(Context c) {        mContext = c;    }    public int getCount() {        return mThumbIds.length;    }    public Object getItem(int position) {        return null;    }    public long getItemId(int position) {        return 0;    }    // create a new ImageView for each item referenced by the Adapter    public View getView(int position, View convertView, ViewGroup parent) {        ImageView imageView;        if (convertView == null) {  // if it's not recycled, initialize some attributes            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(mThumbIds[position]);        return imageView;    }    // references to our images    private Integer[] mThumbIds = {            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_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_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    };}