我想创建图像的幻灯片放映和有关图像的信息。我从 json 获取图像名称并从sd 卡获取图像。我想显示像 ViewPager 这样的幻灯片。我正在解析 json 并存储到数据库中。
问题是
1）如何从特定名称获取图像，因为我想显示有关它的信息。
2) 我想实现延迟加载，因为我有 500 多张图像，大小为 900+kb/图像。
下面是我的json格式
[{"Style_RefNo":"SJBG1175","Style_GWT":"5.64","Style_DWT":"0.27","Style_CSWT":"0","ImageName":"SJBG1175.jpg","MainCatname":"BanglesBracelets","MainCatid":"77"}]
下面是我成功实现视图寻呼机和图像正常显示的代码。但我面临以上2个问题请帮助我
public class ViewRing extends Activity
{
// Declare Variables
private ProgressDialog pd;
public static DataSource dataSource;
List<GetStyleData> styledata;
ViewPager viewPager;
PagerAdapter adapter;
String[] rank;
String[] country;
String[] population;
String[] cswt;
String[] category;
int[] flag;
File[] listFile;
Button btnHome;
ArrayList<String> f = new ArrayList<String>();// list of file paths
ArrayList<String> refNo = new ArrayList<String>();
ArrayList<String> GWT = new ArrayList<String>();
ArrayList<String> DWT = new ArrayList<String>();
ArrayList<String> CSWT = new ArrayList<String>();
ArrayList<String> Category = new ArrayList<String>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the view from viewpager_main.xml
setContentView(R.layout.viewpager_main);
dataSource = new DataSource(ViewRing.this);
pd = new ProgressDialog(ViewRing.this);
getFromSdcard();
// Generate sample data
styledata = dataSource.getRingData();
for(int i = 0 ; i < styledata.size() ; i++)
{
String tempRefNo = styledata.get(i).getStyle_RefNo();
String tempGWT = styledata.get(i).getStyle_GWT();
String tempDWT = styledata.get(i).getStyle_DWT();
String tempCSWT = styledata.get(i).getStyle_CSWT();
String tempCategory = styledata.get(i).getMainCatname();
refNo.add(tempRefNo);
GWT.add(tempGWT);
DWT.add(tempDWT);
CSWT.add(tempCSWT);
Category.add(tempCategory);
Log.v("RefNo", ""+tempRefNo);
Log.v("GWT", ""+tempGWT);
Log.v("DWT", ""+tempDWT);
Log.v("CSWT", ""+tempCSWT);
Log.v("Category", ""+tempCategory);
}
// Locate the ViewPager in viewpager_main.xml
viewPager = (ViewPager) findViewById(R.id.pager);
// Pass results to ViewPagerAdapter Class
adapter = new ViewPagerAdapter(this, rank, country, population, cswt, category, flag);
// Binds the Adapter to the ViewPager
viewPager.setAdapter(adapter);
btnHome = (Button)findViewById(R.id.btnHome);
btnHome.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
class RingTask extends AsyncTask<Void, Void, Object>
{
@Override
protected void onPreExecute()
{
// TODO Auto-generated method stub
super.onPreExecute();
pd.setTitle("Wait !");
pd.setMessage("Loading ....");
pd.show();
}
@Override
protected Object doInBackground(Void... params)
{
// TODO Auto-generated method stub
Intent iRing = new Intent(ViewRing.this, Title.class);
startActivity(iRing);
return null;
}
@Override
protected void onPostExecute(Object result)
{
// TODO Auto-generated method stub
super.onPostExecute(result);
if(pd.isShowing())
{
pd.dismiss();
}
}
}
new RingTask().execute();
}
});
}
public void getFromSdcard()
{
// File file= new File(android.os.Environment.getExternalStorageDirectory(),"MapleBear");
File file = new File("/mnt/sdcard/FinalView/Rings");
if (file.isDirectory())
{
listFile = file.listFiles();
for (int i = 0; i < listFile.length; i++)
{
f.add(listFile[i].getAbsolutePath());
}
}
}
public class ViewPagerAdapter extends PagerAdapter
{
// Declare Variables
Context context;
String[] rank;
String[] country;
String[] population;
String[] cswt;
String[] category;
int[] flag;
LayoutInflater inflater;
public ViewPagerAdapter(Context context, String[] rank, String[] country, String[] population,String[] cswt,String[] category, int[] flag)
{
this.context = context;
this.rank = rank;
this.country = country;
this.population = population;
this.cswt = cswt;
this.category = category;
this.flag = flag;
}
@Override
public int getCount()
{
return refNo.size();
}
@Override
public boolean isViewFromObject(View view, Object object)
{
return view == ((RelativeLayout) object);
}
@Override
public Object instantiateItem(ViewGroup container, int position)
{
// Declare Variables
TextView txtrank;
TextView txtcountry;
TextView txtpopulation;
TextView txtcswt;
TextView txtCategoury;
ImageView imgflag;
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.viewpager_item, container, false);
// Locate the TextViews in viewpager_item.xml
txtrank = (TextView) itemView.findViewById(R.id.rank);
txtcountry = (TextView) itemView.findViewById(R.id.country);
txtpopulation = (TextView) itemView.findViewById(R.id.population);
txtcswt = (TextView) itemView.findViewById(R.id.cswt);
txtCategoury = (TextView) itemView.findViewById(R.id.categoury);
// Capture position and set to the TextViews
txtrank.setText("Ref. No :- "+refNo.get(position).toString());
txtcountry.setText("Gold Weight :- "+GWT.get(position).toString());
txtpopulation.setText("Diamond Weight :- "+DWT.get(position).toString());
txtcswt.setText("Color Stone Weight :- "+CSWT.get(position).toString());
txtCategoury.setText("Category :- "+Category.get(position).toString());
imgflag = (ImageView) itemView.findViewById(R.id.flag);
BitmapFactory.Options op = new BitmapFactory.Options();
op.inSampleSize = 3;
Bitmap myBitmap = BitmapFactory.decodeFile(f.get(position),op);
imgflag.setImageBitmap(myBitmap);
((ViewPager) container).addView(itemView);
return itemView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object)
{
((ViewPager) container).removeView((RelativeLayout) object);
}
}
// Not using options menu in this tutorial
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
请帮帮我谢谢