與Android的

Question

火力地堡數據庫的WebView實現我想要實現webView的與火力地堡所以，如果我在火力數據庫添加URL它就會在我的web視圖應用在實時實施，我已經通過數據庫成功地實現了文本和圖像，但無法正常使用webView，我搜索了很多選項，但都不適合我，請幫忙。如果你想要更多的細節，我可以提供給你。

我使用過Android Studio

下面是我的火力地堡實施的圖像和文本的Java類代碼

@Override 
    public void onStart() { 
     super.onStart(); 
     FirebaseUser currentUser = mAuth.getCurrentUser(); 
     if (currentUser == null) { 
      sentToStart(); 
     } 
     FirebaseRecyclerAdapter <post, postViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<post, postViewHolder>(

      post.class, 
      R.layout.post_row_recycle_home, 
      postViewHolder.class, 
      mDatabaseReference 
    ) { 
     @Override 
     protected void populateViewHolder(postViewHolder viewHolder, post model, int position) { 
      viewHolder.setTitle(model.getTitle()); 
      viewHolder.setdescription(model.getDescription()); 
      viewHolder.setimage(getApplicationContext(), model.getImage()); 
      viewHolder.setsource(model.getSource()); 
     } 
    }; 
    mrecyclerView.setAdapter(firebaseRecyclerAdapter); 
} 
public static class postViewHolder extends RecyclerViewPager.ViewHolder{ 

    View mView; 

    public postViewHolder(View itemView) { 
     super(itemView); 
     mView = itemView; 
    } 

    public void setTitle(String title){ 
     TextView post_title = (TextView)mView.findViewById(R.id.title_cardView); 
     post_title.setText(title); 
    } 
    public void setsource(String source){ 
     TextView post_source = (TextView)mView.findViewById(R.id.source_cardView); 
     post_source.setText(source); 
    } 

    public void setdescription(String description){ 
     TextView post_description = (TextView)mView.findViewById(R.id.description_cardView); 
     post_description.setText(description); 
    } 

    public void setimage(final Context ctx, final String image){ 
     final ImageView post_image = (ImageView)mView.findViewById(R.id.post_image); 
     Picasso.with(ctx).load(image).networkPolicy(NetworkPolicy.OFFLINE).into(post_image, new Callback() { 

      @Override 
      public void onSuccess() { 
      } 
      @Override 
      public void onError() { 
       Picasso.with(ctx).load(image).into(post_image); 
      } 
     }); 
    } 
} 

的getter/setter的Java類

public class post { 

    private String title; 
    private String description; 
    private String image; 
    private String source; 



    public String getSource() { 
     return source; 
    } 

    public void setSource(String source) { 
     this.source = source; 
    } 

    public post(){ 
    } 

    public post(String title, String description, String image, String source) { 
     this.title = title; 
     this.description = description; 
     this.image = image; 
     this.source = source; 
    } 

    public String getTitle() { 
     return title; 
    } 

    public void setTitle(String title) { 
     this.title = title; 
    } 

    public String getDescription() { 
     return description; 
    } 

    public void setDescription(String description) { 
     this.description = description; 
    } 

    public String getImage() { 
     return image; 
    } 

    public void setImage(String image) { 
     this.image = image; 
    } 

} 

已更新的WebView的Java活動

public class webViewNews extends AppCompatActivity { 

    private WebView webviewthis; 
    private DatabaseReference mDatabaseReference; 
    private DatabaseReference mdataRef; 



    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.webview_page); 
     mdataRef = FirebaseDatabase.getInstance().getReference().child("webView"); 
     webviewthis = (WebView)findViewById(R.id.webView_news); 
     webviewthis.setWebViewClient(new WebViewClient()); 
     webviewthis.getSettings().setJavaScriptEnabled(true); 
     webviewthis.getSettings().setLoadsImagesAutomatically(true); 


     mdataRef.child("webView").addValueEventListener(new ValueEventListener() { 
      @Override 
      public void onDataChange(DataSnapshot dataSnapshot) { 
        dataSnapshot.child("webView").getValue(); 
        webviewthis.loadUrl(""); 

      } 

      @Override 
      public void onCancelled(DatabaseError databaseError) { 

      } 
     }); 

    } 
    @Override 
    protected void onStart() { 
     super.onStart(); 
     } 
} 

Answer 1

首先，正如我在你的代碼中看到，您使用.child("webView")兩次。一旦在DatabaseReference和一次當你添加ValueEventListener。這就是你在數據庫中所擁有的東西嗎？如果數據庫中沒有重複的子項，則需要刪除其中的一個。

您已在mdataRef上添加了ValueEventListener，但您在此處無所作爲。您的onDataChange()方法爲空。請記住，每次數據庫發生更改時都會觸發此方法。因此，爲了顯示一些內容，您需要根據數據庫結構從dataSnapshot對象中獲取數據，並將其顯示在那裏。

希望它有幫助。