我試圖第一次構建viewpager。我在主onCreate方法中填充一個ArrayList的視圖並將它傳遞給PagerAdapter的構造函數。活動啓動正常,我可以看到ViewPager(或至少它的背景),但沒有任何視圖出現在它中,我只看到空白背景。我嘗試過膨脹佈局XML,我知道它們在其他小部件中工作,所以它不會成爲一個問題。我猜測它與我編寫instantiateObject方法的方式有關。總之,這裏是我的適配器:viewpager中沒有出現的視圖
public class StoryAdapter extends PagerAdapter {
private Context ctx;
private ViewBuilder viewBuilder;
public StoryAdapter(Context ctx, ArrayList<View> views){
this.ctx = ctx;
}
@Override
public int getCount() {
return views.size();
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
// TODO Auto-generated method stub
return false;
}
@Override
public Object instantiateItem(View arg0, int arg1) {
View v = views.get(arg1);
((ViewPager) arg0).addView(v);
return v;
}
@Override
public void destroyItem(View pager, int arg1, Object view) {
((ViewPager) pager).removeView((View) view);
}
}
這裏是我的onCreate():
public class ShowStory extends Activity {
public int totalPages;
Button backBtn;
public String text;
public ArrayList<View> views;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_story);
backBtn = (Button)findViewById(R.id.backBtn);
backBtn.setOnClickListener(new OnClickListener() {
public void onClick(View view){
Intent intent = new Intent();
setResult(RESULT_CANCELED, intent);
finish();
}
});
ViewPager vp = (ViewPager)findViewById(R.id.storyFlipper);
views = new ArrayList<View>();
View v0 = getLayoutInflater().inflate(R.layout.galleryview, null);
TextView v0t = (TextView)v0.findViewById(R.id.headline);
v0t.setText("COVER1");
View v1 = getLayoutInflater().inflate(R.layout.coverpage, null);
// TextView v1t = (TextView)findViewById(R.id.coverText);
// v1t.setText("COVER2");
View v2 = getLayoutInflater().inflate(R.layout.coverpage, null);
// TextView v2t = (TextView)findViewById(R.id.coverText);
// v2t.setText("COVER3");
views.add(v0);
views.add(v1);
views.add(v2);
StoryAdapter sa = new StoryAdapter(this, views);
vp.setAdapter(sa);
PS我這樣做主要是爲了教育目的,這顯然是一個很簡單的例子。任何幫助將不勝感激!
------編輯:我想你的建議:
@Override
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int resId = 0;
switch (position) {
case 0:
resId = R.layout.coverpage;
break;
case 1:
resId = R.layout.coverpage;
break;
case 2:
resId = R.layout.coverpage;
break;
case 3:
resId = R.layout.coverpage;
break;
}
View view = inflater.inflate(resId, null);
((ViewPager) collection).addView(view, 0);
return view;
}
,並有同樣的結果 - 我看到了viewpager的空白背景,但沒有意見出現
他們爲什麼不讓isViewFromObject()抽象!?不管怎樣,謝謝!你幫了我。 –
謝謝。很好的幫助 –