android开发之ImageSwitcher

Question

package your.packag;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class Phone00Activity extends Activity {
private int picture[]=
{R.drawable.aaa,
R.drawable.bbb,
R.drawable.ccc};

private Button bt1;
private Button bt2;
private ImageSwitcher imageswitcher;
private int n=0;

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

bt1=(Button)findViewById(R.id.bt1);
bt1.setText("下一张");
bt2=(Button)findViewById(R.id.bt2);
bt2.setText("上一张");
imageswitcher.setFactory(new viewfactory());

imageswitcher.setImageResource(picture[0]);

bt1.setOnClickListener(new OnClickListener() {

public void onClick(View v) {
n++;
if(n==picture.length){
n=0;
}
imageswitcher.setImageResource(picture[n]);// TODO Auto-generated method stub

}
});

bt2.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
n--;
if(n<0){
n=picture.length-1;
}
// TODO Auto-generated method stub
imageswitcher.setImageResource(picture[n]);
}
});

}
public class viewfactory implements ViewFactory{

@Override
public View makeView() {

ImageView v=new ImageView(Phone00Activity.this);

// TODO Auto-generated method stub
return v;
}

}

}

运行有误，求解

Answer 1

运行时错误，很可能是有局部变量没有初始化

Answer 2

把你的logcat信息发出来呗

Answer 3

crash怎么办，看异常