リサイクルビューアアダプタを使用してsqliteからrecyclerviewにデータを表示

-2

私はデータベースにデータを保存するアプリケーションを作成しています。リサイクルモニタを使用してrecyclerviewにデータを表示していません。チェックしてください。ここリサイクルビューアアダプタを使用してsqliteからrecyclerviewにデータを表示

が私のファイルです：MainActivity.java

import android.content.Intent; 
import android.database.Cursor; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.view.Menu; 
import android.view.MenuItem; 

import java.util.ArrayList; 


public class MainActivity extends AppCompatActivity { 

    private RecyclerView applist; 
    ArrayList<Guides> guides; 
    GuideAdapter adapter; 
    GuideDB guideDB; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     guideDB = new GuideDB(this); 

     guides = new ArrayList<>(); 

     applist = (RecyclerView) findViewById(R.id.app_list); 
     applist.setHasFixedSize(true); 
     applist.setLayoutManager(new LinearLayoutManager(this)); 
     adapter = new GuideAdapter(this,guides); 
     applist.setAdapter(adapter); 

     try { 
      Cursor cursor = guideDB.getGuides("SELECT * FROM GUIDE_LIST"); 
      while (cursor.moveToNext()){ 
       int guide_id = cursor.getInt(0); 
       String post_tile = cursor.getString(1); 
       String post_desc = cursor.getString(2); 
       String post_address = cursor.getString(3); 
       byte [] post_image = cursor.getBlob(4); 

       Guides g = new Guides(guide_id,post_tile,post_desc,post_address,post_image); 
       guides.add(g);} 
     }catch (Exception e){e.printStackTrace();} 



    } 



    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 

     getMenuInflater().inflate(R.menu.main_menu,menu); 

     return super.onCreateOptionsMenu(menu); 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 

     if(item.getItemId() == R.id.action_add){ 

      startActivity(new Intent(MainActivity.this,PostActivity.class)); 
     } 

     return super.onOptionsItemSelected(item); 
    } 
}

PostActivity.java

import android.content.Intent; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.net.Uri; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.ImageButton; 
import android.widget.Toast; 

import java.io.ByteArrayOutputStream; 
import java.io.FileNotFoundException; 
import java.io.InputStream; 

public class PostActivity extends AppCompatActivity { 

    public ImageButton mSelectImage; 
    public EditText mPostTitle; 
    public EditText mPostDesc; 
    public EditText mPostAddress; 
    public Button mSubmitbtn; 
    private static final int GALLERY_REQUEST= 1; 
    GuideDB guideDB; 
    Bitmap bitmap; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_post); 


     guideDB = new GuideDB(this); 
     mSelectImage = (ImageButton) findViewById(R.id.imageSelect); 
     mPostTitle = (EditText) findViewById(R.id.titleField); 
     mPostDesc = (EditText) findViewById(R.id.descField); 
     mPostAddress = (EditText) findViewById(R.id.addressField); 
     mSubmitbtn = (Button) findViewById(R.id.submitButton); 


     mSelectImage.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 

       Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT); 
       galleryIntent.setType("image/*"); 
       startActivityForResult(galleryIntent,GALLERY_REQUEST); 
      } 
     }); 
     mSubmitbtn.setOnClickListener(new View.OnClickListener(){ 
      @Override 
      public void onClick(View view){ 

       if(!mPostTitle.getText().toString().isEmpty() && !mPostDesc.getText().toString().isEmpty() && !mPostAddress.getText().toString().isEmpty()) 
       { 
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); 
        bitmap.compress(Bitmap.CompressFormat.PNG,50,outputStream); 
        byte[] byteArray = outputStream.toByteArray(); 

        try { 
         guideDB.addGuide(mPostTitle.getText().toString(), 
           mPostDesc.getText().toString(), 
           mPostAddress.getText().toString(),byteArray 
         ); 
         Toast.makeText(getApplicationContext(),"Added successfully!",Toast.LENGTH_LONG).show(); 
        }catch (Exception e){e.printStackTrace();} 
       } 

      } 
     }); 

} 


    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 

     if(requestCode == GALLERY_REQUEST && resultCode == RESULT_OK) { 

      Uri mimageUri = data.getData(); 
      try { 
       InputStream inputstream = getContentResolver().openInputStream(mimageUri); 

       bitmap = BitmapFactory.decodeStream(inputstream); 
       mSelectImage.setImageBitmap(bitmap); 

      }catch (FileNotFoundException e){e.printStackTrace();} 

     } 
    } 

}

GuideDB.java

import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.database.sqlite.SQLiteStatement; 

/** 
* Created by 291 on 14.12.2017. 
*/ 

public class GuideDB extends SQLiteOpenHelper { 

    private static final int DATABASE_VERSION= 1; 
    private static final String DATABASE_NAME= "guide_db"; 
    private static final String TABLE_NAME = "GUIDE_LIST"; 
    private static String GUIDE_ID = "guide_id"; 
    private static String GUIDE_TITLE = "guide_title"; 
    private static String GUIDE_DESC = "guide_desc"; 
    private static String GUIDE_ADDRESS = "guide_address"; 
    private static String GUIDE_IMG = "guides_image"; 

    public GuideDB(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     String CREATE_TABLE = "CREATE TABLE" + TABLE_NAME + "(" 
       + GUIDE_ID + "INTEGER PRIMARY KEY AUTOINCREMENT" 
       + GUIDE_TITLE + "TEXT" 
       + GUIDE_DESC + "TEXT" 
       + GUIDE_ADDRESS + "TEXT" 
       + GUIDE_IMG + "BLOB" + ")"; 
     db.execSQL(CREATE_TABLE); 

    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL("DROP TABLE IF EXISTS "+ TABLE_NAME); 
     onCreate(db); 

    } 

    public void addGuide (String title,String desc,String address,byte[] image){ 
     SQLiteDatabase gdb = getWritableDatabase(); 

     try 
     { 
      String sql = "INSERT INTO GUIDE_LIST VALUES(NULL,?,?,?)"; 
      SQLiteStatement statement = gdb.compileStatement(sql); 
      statement.clearBindings(); 
      statement.bindString(1,title); 
      statement.bindString(2,desc); 
      statement.bindString(3,address); 
      statement.bindBlob(4,image); 
      statement.execute(); 


     }catch (Exception e){e.printStackTrace();} 

    } 

    public Cursor getGuides(String sql){ 
     SQLiteDatabase gdb = getReadableDatabase(); 
     return gdb.rawQuery(sql,null); 

    } 
}

GuideAdapter.java

import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
import android.widget.TextView; 

import java.util.ArrayList; 

/** 
* Created by 291 on 14.12.2017. 
*/ 

public class GuideAdapter extends RecyclerView.Adapter<GuideAdapter.ViewHolder> { 
    private Context ctx; 
    private ArrayList<Guides> guidelist; 

    public GuideAdapter(Context ctx, ArrayList<Guides> guidelist) { 
     this.ctx = ctx; 
     this.guidelist = guidelist; 
    } 

    @Override 
    public GuideAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.guide_row,parent,false); 
     return new ViewHolder(view); 
    } 


    @Override 
    public void onBindViewHolder(GuideAdapter.ViewHolder holder, int position) { 

     Guides guides = guidelist.get(position); 
     holder.psttitle.setText(guides.getPost_title()); 
     holder.pstdesc.setText(guides.getPost_desc()); 
     holder.pstaddres.setText(guides.getPost_address()); 

     byte [] postimg = guides.getPost_image(); 
     Bitmap bitmap = BitmapFactory.decodeByteArray(postimg,0,postimg.length); 
     holder.pstimg.setImageBitmap(bitmap); 


    } 

    @Override 
    public int getItemCount() { 
     return guidelist.size(); 
    } 

    public class ViewHolder extends RecyclerView.ViewHolder{ 

     public ImageView pstimg; 
     public TextView psttitle; 
     public TextView pstdesc; 
     public TextView pstaddres; 
     public int id; 


     public ViewHolder(View itemView) { 
      super(itemView); 

      pstimg = (ImageView) itemView.findViewById(R.id.post_image); 
      psttitle = (TextView) itemView.findViewById(R.id.post_title); 
      pstdesc = (TextView) itemView.findViewById(R.id.post_title); 
      pstaddres = (TextView) itemView.findViewById(R.id.post_address); 
     } 
    } 
}

Guides.java

public class Guides { 
    private int guide_id; 
    private String post_title,post_desc,post_address; 
    private byte [] post_image; 



    public Guides(int guide_id, String post_title, String post_desc, String post_address, byte [] post_image) { 
     this.guide_id = guide_id; 
     this.post_title = post_title; 
     this.post_desc = post_desc; 
     this.post_address = post_address; 
     this.post_image = post_image; 


    } 

    public int getGuide_id() { 
     return guide_id; 
    } 

    public void setGuide_id(int guide_id) { 
     this.guide_id = guide_id; 
    } 

    public String getPost_title() { 
     return post_title; 
    } 

    public void setPost_title(String post_title) { 
     this.post_title = post_title; 
    } 

    public String getPost_desc() { 
     return post_desc; 
    } 

    public void setPost_desc(String post_desc) { 
     this.post_desc = post_desc; 
    } 

    public String getPost_address() { 
     return post_address; 
    } 

    public void setPost_address(String post_address) { 
     this.post_address = post_address; 
    } 

    public byte[] getPost_image() { 
     return post_image; 
    } 

    public void setPost_image(byte[] post_image) { 
     this.post_image = post_image; 
    } 
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    tools:context="com.ugurcangursen.guideappsqlite.MainActivity"> 

    <android.support.v7.widget.RecyclerView 
     android:id="@+id/app_list" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:layout_alignParentTop="true" 
     android:layout_centerHorizontal="true" 
     android:padding="10dp"></android.support.v7.widget.RecyclerView> 

</RelativeLayout>

activity_post.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    tools:context="com.ugurcangursen.guideappsqlite.PostActivity"> 


    <ImageButton 
     android:id="@+id/imageSelect" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:layout_centerHorizontal="true" 
     android:adjustViewBounds="true" 
     android:background="#00ffffff" 
     android:scaleType="centerCrop" 
     app:srcCompat="@drawable/add_btn" /> 

    <EditText 
     android:id="@+id/titleField" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@+id/imageSelect" 
     android:layout_centerHorizontal="true" 
     android:layout_marginLeft="20dp" 
     android:layout_marginRight="20dp" 
     android:layout_marginTop="20dp" 
     android:background="@drawable/input_outline" 
     android:hint="Post Title..." 
     android:inputType="textPersonName" 
     android:padding="10dp" 
     android:singleLine="true" /> 

    <EditText 
     android:id="@+id/descField" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@+id/titleField" 
     android:layout_centerHorizontal="true" 
     android:layout_marginLeft="20dp" 
     android:layout_marginRight="20dp" 
     android:layout_marginTop="20dp" 
     android:background="@drawable/input_outline" 
     android:hint="Post Description..." 
     android:inputType="textMultiLine" 
     android:padding="10dp" /> 

    <EditText 
     android:id="@+id/addressField" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@+id/descField" 
     android:layout_centerHorizontal="true" 
     android:layout_marginLeft="20dp" 
     android:layout_marginRight="20dp" 
     android:layout_marginTop="20dp" 
     android:background="@drawable/input_outline" 
     android:hint="Adres..." 
     android:inputType="textMultiLine" 
     android:padding="10dp" /> 

    <Button 
     android:id="@+id/submitButton" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_alignParentBottom="true" 
     android:layout_centerHorizontal="true" 
     android:background="@color/colorPrimary" 
     android:text="SUBMIT POST" 
     android:textColor="@android:color/white" /> 

</RelativeLayout>

guide_r ow.xml

<?xml version="1.0" encoding="utf-8"?> 
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_margin="20dp" 
    xmlns:tools="http://schemas.android.com/tools" 
    xmlns:app="http://schemas.android.com/apk/res-auto"> 


    <LinearLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:orientation="vertical"> 

     <ImageView 
      android:id="@+id/post_image" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:adjustViewBounds="true" 
      android:scaleType="centerCrop" 
      app:srcCompat="@drawable/add_btn" /> 

     <TextView 
      android:id="@+id/post_title" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:padding="15dp" 
      android:textSize="16dp" 
      android:textStyle="bold" 
      tools:text="Başlık" /> 

     <TextView 
      android:id="@+id/post_desc" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:padding="15dp" 
      tools:text="Açıklama" /> 

     <TextView 
      android:id="@+id/post_address" 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:padding="15dp" 
      tools:text="Adres" /> 

    </LinearLayout> 

</android.support.v7.widget.CardView>

出典

2017-12-14 Uğurcan Gürşen

投稿したすべてのコードを確認していません。ただし、空のソース（ガイド）を使用してアドパートを設定しているように見えるので、何も表示されません。

onCreate方法の次のバージョンは

protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    guideDB = new GuideDB(this); 

    guides = new ArrayList<>(); 

    applist = (RecyclerView) findViewById(R.id.app_list); 
    applist.setHasFixedSize(true); 
    applist.setLayoutManager(new LinearLayoutManager(this)); 
    //adapter = new GuideAdapter(this,guides); //<<<< MOVED 
    //applist.setAdapter(adapter); //<<<< MOVED 

    try { 
     Cursor cursor = guideDB.getGuides("SELECT * FROM GUIDE_LIST"); 
     while (cursor.moveToNext()){ 
      int guide_id = cursor.getInt(0); 
      String post_tile = cursor.getString(1); 
      String post_desc = cursor.getString(2); 
      String post_address = cursor.getString(3); 
      byte [] post_image = cursor.getBlob(4); 

      Guides g = new Guides(guide_id,post_tile,post_desc,post_address,post_image); 
      guides.add(g);} 
    }catch (Exception e){e.printStackTrace();} 

    adapter = new GuideAdapter(this,guides); //<<<< MOVED 
    applist.setAdapter(adapter); //<<<< MOVED 
}

が表示されているデータをもたらすことができます

出典

2017-12-15 02:39:07 MikeT

リサイクルビューアアダプタを使用してsqliteからrecyclerviewにデータを表示

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