android - 如何在 fragment 类中使用 View 寻呼机创建滑动图像？

Question

*我想显示来自 WebService 的完整图像，并在前后两侧创建滑动图像。我用过 ViewPager，PagerAdapter 类。 fragment 类是，

package com.Fragment.Classes;




  import java.util.ArrayList;

    import org.json.JSONArray;
    import org.json.JSONException;
    import org.json.JSONObject;

    import com.PersianBeauty.Adapter.ImagePagerAdapter;
    import com.persianbeauty.R;
    import com.utility.ConnectionDetector;
    import com.utility.JSONfunctions;


    import android.annotation.SuppressLint;
    import android.app.Fragment;
    import android.app.FragmentManager;
    import android.app.ProgressDialog;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.support.v4.view.ViewPager;
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.Toast;

    @SuppressLint("ValidFragment")
    public class ModelPortFoliolFragment extends Fragment
    {
        ImagePagerAdapter pagerAdapter;

        ViewPager pager;
        String[] imageUrls;
        View rootView;
        ArrayList<String> imageList;
        // Declare Variables
        JSONObject jsonobject;
        JSONArray jsonarray;

        // JSON Node names
        static  String TAG_MODEL = "model";
        static  String TAG_MODELIMAG1 = "ModelImage";
        static  String TAG_MODEL_IMAGE2 = "ModelImage_2";
        static  String TAG_MODEL_IMAGE3= "ModelImage_3";

        ProgressDialog mProgressDialog;
        String ID;
        public ModelPortFoliolFragment(String ID)
        {
            this.ID=ID;
        }


        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) 
        { 

            rootView = inflater.inflate(R.layout.fragment_model_portfolio, container, false);


            if(!ConnectionDetector.networkStatus(getActivity())) 
            {
                ConnectionDetector.displayNoNetworkDialog(getActivity());
            }
            else 
            {
                new ParseModelPortFolioJSonData().execute();
            }
            pager = (ViewPager) rootView.findViewById(R.id.pager);
            //  pager.setAdapter(new ImagePagerAdapter(imageList,getActivity()));
            //pager.setCurrentItem(pagerPosition);
            pagerAdapter=new ImagePagerAdapter(imageList,getActivity());
            pager.setAdapter(pagerAdapter);
            //pager.setAdapter(new ImagePagerAdapter(imageList,getActivity()));
            //pager.setCurrentItem(pagerPosition);


            return rootView;
        }
    //  @Override
    //  public void onDestroyView()
    //  {
    //      super.onDestroyView();
    //
    //  }
        // DownloadJSON AsyncTask
        public class ParseModelPortFolioJSonData extends AsyncTask<Void, Void, Void>
        {   


            @Override
            protected void onPreExecute() 
            {
                super.onPreExecute();
                mProgressDialog = new ProgressDialog(getActivity());
                mProgressDialog.setMessage("Please wait...");
                //          mProgressDialog.setIndeterminate(false);
                mProgressDialog.setCancelable(false);
                mProgressDialog.show();
            }


            @Override
            protected Void doInBackground(Void... arg0)

            {   imageList=new ArrayList<String>();
            // Create an array

            try {
                //http://www.persianbeautyawards.com/services/GetModelProfile.php?model_id=56
                jsonobject = JSONfunctions.getJSONfromURL(getResources().getString(R.string.base_url).trim() +"GetModelPortfolio.php?model_id="+ID);
                System.out.println(getResources().getString(R.string.base_url).trim() +"GetModelPortfolio.php?model_id="+ID+".....................");
                // Locate the array name in JSON
                System.out.println(jsonobject+".................");
                if(jsonobject !=null)
                {
                    jsonarray = jsonobject.getJSONArray(TAG_MODEL);

                    for (int i = 0; i < jsonarray.length(); i++)
                    {
                        jsonobject = jsonarray.getJSONObject(i);

                        imageList.add(jsonobject.getString(TAG_MODELIMAG1));
                        System.out.println(jsonobject.getString(TAG_MODELIMAG1)+"...........");

                        imageList.add(jsonobject.getString(TAG_MODEL_IMAGE2));
                        System.out.println(jsonobject.getString(TAG_MODEL_IMAGE2)+"...........");

                        imageList.add(jsonobject.getString(TAG_MODEL_IMAGE3));
                        System.out.println(jsonobject.getString(TAG_MODEL_IMAGE3)+"...........");

                    }

                    // Set the JSON Objects into the array
                }


            } catch (JSONException e) {
                Log.e("Error", e.getMessage());
                e.printStackTrace();
            }
            return null;
            }

            protected void onPostExecute(Void args) 
            {  
                if(imageList !=null)
                {  
                    pagerAdapter.notifyDataSetChanged();
                    if (rootView != null) {
                        ViewGroup parentViewGroup = (ViewGroup) rootView.getParent();
                        if (parentViewGroup != null) {
                            parentViewGroup.removeAllViews();
                        }
                    }

                }


                else
                {
                    Toast.makeText(getActivity(),"Server Error try Again", Toast.LENGTH_LONG).show();
                }
                mProgressDialog.dismiss();
            }
        }
    }

我使用了从 PageAdapter 扩展而来的 Adapter 类， 我的 PageAdapter 类是，

PageAdapter:

 package com.PersianBeauty.Adapter;



import java.util.ArrayList;

import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.persianbeauty.R;

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;



public class ImagePagerAdapter extends PagerAdapter
{
    LayoutInflater inflator;
    ImageView imgDisplay;
 Context context;
 ArrayList<String> slideShowImages;
 private ImageLoader imageLoader;
 public ImagePagerAdapter(ArrayList<String> slideShowImages,Context context)
 {
  this.context=context;
  this.slideShowImages =slideShowImages;
  imageLoader = ImageLoader.getInstance();
  imageLoader.init(ImageLoaderConfiguration.createDefault(context));
 }
 @Override
 public int getCount() 
 {
  return slideShowImages.size();
 }

 @Override
 public boolean isViewFromObject(View view, Object object) {
  return view == ((ImageView) object);
 }

 @Override
 public Object instantiateItem(ViewGroup container, int position)
 {
     inflator = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
     View viewLayout = inflator.inflate(R.layout.item_pager_view, container,
             false);
     imgDisplay = (ImageView) viewLayout.findViewById(R.id.image);
//  BitmapFactory.Options options = new BitmapFactory.Options();
//  options.inPreferredConfig = Bitmap.Config.ARGB_8888;
//  Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
//  imgDisplay.setImageBitmap(bitmap);
//   

  System.out.println("ImageUrl---------------------"+slideShowImages.get(position));
  imageLoader.displayImage(slideShowImages.get(position).trim(), imgDisplay);
  ((ViewPager) container).addView(imgDisplay, 0);
  return imgDisplay;

 }

 @Override
 public void destroyItem(ViewGroup container, int position, Object object)
 {
  ((ViewPager) container).removeView((ImageView) object);
 }
}

fragment 布局:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

扩展 imageLoader 类的图像布局，

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="1dip" >

    <ImageView
        android:id="@+id/image"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:adjustViewBounds="true"
         />


</FrameLayout>

当我运行这段代码时，它给出了以下错误并且没有在 View 页面上加载任何类型的图像，

 02-12 09:13:22.034: E/AndroidRuntime(3050): FATAL EXCEPTION: main
02-12 09:13:22.034: E/AndroidRuntime(3050): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.view.ViewGroup.addViewInner(ViewGroup.java:3339)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.view.ViewGroup.addView(ViewGroup.java:3210)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager.addView(ViewPager.java:1304)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.view.ViewGroup.addView(ViewGroup.java:3155)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at com.PersianBeauty.Adapter.ImagePagerAdapter.instantiateItem(ImagePagerAdapter.java:62)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:832)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager.populate(ViewPager.java:982)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:550)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:509)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager.dataSetChanged(ViewPager.java:908)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.ViewPager$PagerObserver.onChanged(ViewPager.java:2819)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.database.DataSetObservable.notifyChanged(DataSetObservable.java:37)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.support.v4.view.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:276)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at com.Fragment.Classes.ModelPortFoliolFragment$ParseModelPortFolioJSonData.onPostExecute(ModelPortFoliolFragment.java:151)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at com.Fragment.Classes.ModelPortFoliolFragment$ParseModelPortFolioJSonData.onPostExecute(ModelPortFoliolFragment.java:1)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.os.AsyncTask.finish(AsyncTask.java:631)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.os.Handler.dispatchMessage(Handler.java:99)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.os.Looper.loop(Looper.java:137)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at android.app.ActivityThread.main(ActivityThread.java:5041)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at java.lang.reflect.Method.invokeNative(Native Method)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at java.lang.reflect.Method.invoke(Method.java:511)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
02-12 09:13:22.034: E/AndroidRuntime(3050):     at dalvik.system.NativeStart.main(Native Method)

请给我一些建议。

Answer 1

在Activity中创建一个名为adapter的属性:

private ImagePagerAdapter adapter;

在 onCreate 中:

adapter= new ImagePagerAdapter(imageList,getActivity());

只需调用 adapter.notifyDataSetChange():

    if(imageList !=null)
        {
            adapter.notifyDataSetChange();
        }