package com.tyut.gridview01;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class PictureActivity extends Activity {
private String[] titles = {"MM1","MM2","MM3","MM4","MM5","MM6","MM7","MM8","MM9","MM10"};
private Integer[] ps =new Integer[]{R.drawable.g1,R.drawable.g2,R.drawable.g3,R.drawable.g4,R.drawable.g5,R.drawable.g6,R.drawable.g7,R.drawable.g8,R.drawable.g9,R.drawable.g10};
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_grid);
GridView grid = (GridView) findViewById(R.id.grid);
grid.setAdapter(new PictureAdapter(titles, ps, this));
grid.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position,
long arg3) {
Log.i("MainActivity", "position："+position);
Toast.makeText(PictureActivity.this, " "+position, Toast.LENGTH_SHORT).show();
}
});
}
}
class PictureAdapter extends BaseAdapter{
private static final String TAG = "MainActivity";
private LayoutInflater inflater;
private List<Picture> pictures;
public PictureAdapter(String[] titles ,Integer[] ps,Context context){
super();
pictures = new ArrayList<Picture>();
inflater = LayoutInflater.from(context);
for (int i = 0; i < ps.length; i++) {
Picture p = new Picture(titles[i],ps[i]);
pictures.add(p);
}
}
@Override
public int getCount() {
// TODO Auto-generated method stub
if (null !=pictures) {
return pictures.size();
}else{
return 0;
}
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return pictures.get(position);
}
@Override
public long getItemId(int id) {
// TODO Auto-generated method stub
return id;
}
@Override
public View getView(int position, View convertview, ViewGroup arg2) {
// TODO Auto-generated method stub
ViewHolder viewHolder;
if (convertview == null) {
convertview = inflater.inflate(R.layout.activity_griditem, null);
viewHolder = new ViewHolder();
Picture pic =pictures.get(position);
int id = pic.getId();
## ((ImageView)viewHolder.image).setImageResource(id);
String t =pic.getTitle();
((TextView)viewHolder.title).setText(t);
convertview.setTag(viewHolder);
}else{
viewHolder = (ViewHolder) convertview.getTag();
}
viewHolder.title.setText(pictures.get(position).getTitle());
viewHolder.image.setImageResource(pictures.get(position).getId());
Log.i(TAG, "<<<<<<<<"+position);
return convertview;
}
class ViewHolder{
public TextView title;
public ImageView image;
}
public class Picture {
private String title;
private int id ;
public Picture(String title,int id){
this.title =title;
this.id =id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
}
问题：
((ImageView)viewHolder.image).setImageResource(id);
说空指针异常
