我无法从资源文件夹加载图片。我想要做的是在用户点击图像将切换的按钮后。我的资产文件夹中有6个图像，我想知道如何在每次点击后加载新图像。
基本上我想要一个后退和下一个按钮，它将滚动图像。我想用android-view寻呼机实现它。这有可能实现吗？在网上有什么教程可以告诉我这个吗？现在我打电话
private int [] images = {R.drawable.airplane, R.drawable.bike,...
但我现在想将所有内容存储在资产文件夹中
public class MainActivity extends Activity {
private int [] images = {R.drawable.airplane, R.drawable.bike, R.drawable.boat,
R.drawable.bus2,R.drawable.car,R.drawable.train};
private ViewPager mViewPager;
private MyPagerAdapter myPagerAdapter;
private Button nextBtn, preBtn;
private TextView positionText;
private int imageCount =images.length;
//HashMap<Integer, String> map = new HashMap<Integer, String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/* Initialize every object */
//String whatString = map.get(R.drawable.airplane);
myPagerAdapter = new MyPagerAdapter();
nextBtn = (Button)findViewById(R.id.nextBtn);
preBtn = (Button)findViewById(R.id.prevBtn);
positionText= (TextView)findViewById(R.id.position);
mViewPager =(ViewPager)findViewById(R.id.viewPager);
mViewPager.setAdapter(myPagerAdapter);
/* ViewPager's setCurrentItem(int) method is used to set first image */
mViewPager.setCurrentItem(0);
positionText.setText("1 of "+ imageCount);
/* OnPageChangeListener */
mViewPager.setOnPageChangeListener(new OnPageChangeListener()
{
@Override
public void onPageSelected(int position) {
positionText.setText((position+1) +" of "+imageCount);
if (position==imageCount-1) {
nextBtn.setEnabled(false);
}
else {
nextBtn.setEnabled(true);
}
if (position==0){
preBtn.setEnabled(false);
}
else {
preBtn.setEnabled(true);
}
}
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
}
@Override
public void onPageScrollStateChanged (int state) {
}
});
/* OnClickListener on buttons to change the image in viewpager */
nextBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mViewPager.setCurrentItem(mViewPager.getCurrentItem()+1);
}
});
preBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mViewPager.setCurrentItem(mViewPager.getCurrentItem()-1);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/* Pager Adapter for ViewPager */
private class MyPagerAdapter extends PagerAdapter {
public MyPagerAdapter() {}
@Override
public int getCount() {
return imageCount;
}
@Override
public View instantiateItem(ViewGroup container, int position){
ImageView mImageView = new ImageView(MainActivity.this);
mImageView.setImageResource(images[position]);
// add ImageView to ViewPager and return it
container.addView(mImageView, LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
return mImageView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
@Override
public boolean isViewFromObject(View view, Object object){
return view == object;
}
}
}