我试图在我的应用程序中查看几个图像,图像链接保存在Firebase实时数据库中 . 我将这些链接作为.JSON上传,并没有手动将它们添加到实时数据库中 . 尝试在我的应用程序中检索这些图像时,它会在单击按钮几秒钟后崩溃以启动图像(“ZamCatalog已停止”) . 在日志中,我收到以下错误 . 我不确定哪里出错了,请帮忙 .
E / AndroidRuntime:FATAL EXCEPTION:main进程:com.example.android.zamcatalog,PID:13529 com.google.firebase.database.DatabaseException:无法在com.google中将java.util.ArrayList类型的值转换为String . android.gms.internal.zzelw.zzb(未知来源:93)com.google.android.gms.internal.zzelw.zza(未知来源:0)com.google.firebase.database.DataSnapshot.getValue(未知来源) :10)在com.google.android上com.example.android.zamcatalog.gameActivity $ 1.onDataChange(gameActivity.java:43)com.google.android.gms.internal.zzegf.zza(未知来源:13) . gms.internal.zzeia.zzbyc(未知来源:2)at com.google.android.gms.internal.zzeig.run(未知来源:71)在android.os.Handler.handleCallback(Handler.java:789)在android位于java.lang.reflect的android.app.ActivityThread.main(ActivityThread.java:6944)的android.os.Looper.loop(Looper.java:164)上的.os.Handler.dispatchMessage(Handler.java:98) . com.android.internal.os.Zygote $ MethodAndArgsCaller.r中的Method.invoke(Native Method) un(Zygote.java:327)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)应用程序终止 .
下面是保存在数据库中的图像的快照
gameActivity代码检索图像
public class gameActivity extends AppCompatActivity {
ViewPager viewPager;
ViewPagerAdapter adapter;
private FirebaseDatabase firebaseDatabase=FirebaseDatabase.getInstance();
private DatabaseReference reference=firebaseDatabase.getReference();
//private DatabaseReference childreference=reference.child("images");
private DatabaseReference gameReference=reference.child("game");
private ArrayList<String> images = new ArrayList<String>();
@Override
protected void onStart() {
super.onStart();
gameReference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String images = dataSnapshot.getValue(String.class);
}
@Override
public void onCancelled(DatabaseError databaseError) {
// Log.w(TAG, "loadImage:onCancelled", databaseError.toException());
}
});
}
viewPager = (ViewPager)findViewById(R.id.viewpager);
adapter = new ViewPagerAdapter(gameActivity.this,images);
viewPager.setAdapter(adapter);
}
ViewPager适配器
public class ViewPagerAdapter extends PagerAdapter {
Activity activity;
ArrayList<String> images;
LayoutInflater inflater;
public ViewPagerAdapter(Activity activity, ArrayList<String> images) {
this.activity = activity;
this.images = images;
}
@Override
public int getCount() {
return images.size();
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
return view == object;
}
@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
inflater = (LayoutInflater) activity.getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemview = inflater.inflate(R.layout.viewpager_item, container, false);
ImageView image;
image = (ImageView) itemview.findViewById(R.id.imageView);
DisplayMetrics dis = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(dis);
int height = dis.heightPixels;
int width = dis.widthPixels;
image.setMinimumHeight(height);
image.setMinimumWidth(width);
try {
Glide.with(activity.getApplicationContext())
//.using(new FirebaseImageLoader())
.load(images.get(position)) //This is were you put the storageReference
.into(image);
} catch (Exception ex) {
}
//notifyDataSetChanged();
container.addView(itemview);
return itemview;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((View) object);
}
}
1 回答
要正确获取所有这些网址,请使用以下代码行:
logcat中的输出将是所有这些URL .