如何添加新字段以保存和从sql数据库中检索图像

Question

我读了this tutorial并编辑了这个并添加了新的字段图像类型Blob但我混淆了如何做到这一点我尝试但不解决请帮助我如何做到这一点？如何在数据库中添加图像我的代码有什么问题我如何浏览和上传图像并保存在数据库中然后检索？请编辑我的代码如何在我的代码中添加新的字段图像？

       public class AddEditCountry extends Activity {

 private long rowID; 
 private EditText nameEt;
 private EditText capEt;
 private EditText codeEt;

 private EditText Donedate;
 private EditText Notes;
 private EditText Person;
 private  ImageView imageView1;

   @Override
   public void onCreate(Bundle savedInstanceState) 
   {
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.add_country);

      nameEt = (EditText) findViewById(R.id.Address);
      capEt = (EditText) findViewById(R.id.Stage);
      codeEt = (EditText) findViewById(R.id.Dueby);

      Donedate = (EditText) findViewById(R.id.Donedate);

      Notes = (EditText) findViewById(R.id.Notes);
      Person = (EditText) findViewById(R.id.Person);

      imageView1 = (ImageView) findViewById(R.id.imageView1);
      Button Browse = (Button) findViewById(R.id.Browse);






      Browse.setOnClickListener(new View.OnClickListener() 
        {
            public void onClick(View v) 
            {               
                Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                intent.setType("image/*");
                startActivityForResult(intent, 0);
            }
        });        






      Bundle extras = getIntent().getExtras(); 

      if (extras != null)
      {
         rowID = extras.getLong("row_id");
         nameEt.setText(extras.getString("name"));  
         capEt.setText(extras.getString("cap"));  
         codeEt.setText(extras.getString("code"));  
         Donedate.setText(extras.getString("Location"));  
         Notes.setText(extras.getString("Notes")); 
         Person.setText(extras.getString("Person")); 
         imageView1.setTag(extras.getString("Image"));
      }

      Button saveButton =(Button) findViewById(R.id.saveBtn);
      saveButton.setOnClickListener(new OnClickListener() {

          public void onClick(View v) 
          {
             if (nameEt.getText().length() != 0)
             {
                AsyncTask<Object, Object, Object> saveContactTask = 
                   new AsyncTask<Object, Object, Object>() 
                   {
                      @Override
                      protected Object doInBackground(Object... params) 
                      {
                         saveContact();
                         return null;
                      }

                      @Override
                      protected void onPostExecute(Object result) 
                      {
                         finish();
                      }
                   }; 

                saveContactTask.execute((Object[]) null); 
             }

             else
             {
                AlertDialog.Builder alert = new AlertDialog.Builder(AddEditCountry.this);
                alert.setTitle(R.string.errorTitle); 
                alert.setMessage(R.string.errorMessage);
                alert.setPositiveButton(R.string.errorButton, null); 
                alert.show();
             }
          } 
     });
   }

   private void saveContact() 
   {
      DatabaseConnector dbConnector = new DatabaseConnector(this);

      if (getIntent().getExtras() == null)
      {
          dbConnector.insertContact(nameEt.getText().toString(),
                  capEt.getText().toString(),
                  codeEt.getText().toString(),
                  Donedate.getText().toString(),
                  Notes.getText().toString(),
                  Person.getText().toString(), null




                  );
      }
      else
      {
         dbConnector.updateContact(rowID,
            nameEt.getText().toString(),
            capEt.getText().toString(), 
            codeEt.getText().toString(), 
            Donedate.getText().toString(),
         Notes.getText().toString(),
          Person.getText().toString(), null


         );
      }
   }











   protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
       super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

       switch(requestCode) {
       case 0:
           if(resultCode == RESULT_OK){
               Uri selectedImage = imageReturnedIntent.getData();
               String[] filePathColumn = {MediaStore.Images.Media.DATA};

               Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
               cursor.moveToFirst();

               int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
               String filePath = cursor.getString(columnIndex); // file path of selected image
               cursor.close();
                       //  Convert file path into bitmap image using below line.
               Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);

                       // put  bitmapimage in your imageview
               imageView1.setImageBitmap(yourSelectedImage);
           }
       }
    }







}











             mport android.os.AsyncTask;
        import android.os.Bundle;
       import android.app.ListActivity;
   import android.content.Intent;
   import android.database.Cursor;
  import android.view.Menu;
  import android.view.MenuInflater;
 import android.view.MenuItem;
   import android.view.View;
  import android.widget.AdapterView;
   import android.widget.CursorAdapter;
  import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
   import android.widget.AdapterView.OnItemClickListener;

   public class CountryList extends ListActivity {

 public static final String ROW_ID = "row_id";
 private ListView conListView;
 private CursorAdapter conAdapter;

 @Override
 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    conListView=getListView();
    conListView.setOnItemClickListener(viewConListener);

    // map each name to a TextView
    String[] from = new String[] { "name" };
    int[] to = new int[] { R.id.countryTextView };
    conAdapter = new SimpleCursorAdapter(CountryList.this, R.layout.country_list,  
        null, from, to);
    setListAdapter(conAdapter); // set adapter
 }


 @Override
 protected void onResume() 
 {
   super.onResume();  
   new GetContacts().execute((Object[]) null);
  } 


 @Override
 protected void onStop() 
 {
   Cursor cursor = conAdapter.getCursor();

   if (cursor != null) 
      cursor.deactivate();

   conAdapter.changeCursor(null);
   super.onStop();
}    


 private class GetContacts extends AsyncTask<Object, Object, Cursor> 
 {
   DatabaseConnector dbConnector = new DatabaseConnector(CountryList.this);

   @Override
   protected Cursor doInBackground(Object... params)
   {
      dbConnector.open();
      return dbConnector.getAllContacts(); 
   } 

   @Override
   protected void onPostExecute(Cursor result)
   {
      conAdapter.changeCursor(result); // set the adapter's Cursor
      dbConnector.close();
   } 
 } 

 @Override
 public boolean onCreateOptionsMenu(Menu menu) 
 {
   super.onCreateOptionsMenu(menu);
   MenuInflater inflater = getMenuInflater();
   inflater.inflate(R.menu.country_menu, menu);
   return true;
 }   

 @Override
 public boolean onOptionsItemSelected(MenuItem item) 
 {
    Intent addContact = new Intent(CountryList.this, AddEditCountry.class);
   startActivity(addContact);
   return super.onOptionsItemSelected(item);
 }

 OnItemClickListener viewConListener = new OnItemClickListener() 
 {
   public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) 
   {         
      Intent viewCon = new Intent(CountryList.this, ViewCountry.class);
      viewCon.putExtra(ROW_ID, arg3);
      startActivity(viewCon);
   }
 };    

 }








      import android.content.ContentValues;
    import android.content.Context;
import android.database.Cursor;
 import android.database.SQLException;
 import android.database.sqlite.SQLiteDatabase;


     public class DatabaseConnector {

private static final String DB_NAME = "WorldCountries";
private SQLiteDatabase database;
private DatabaseOpenHelper dbOpenHelper;

public DatabaseConnector(Context context) {
    dbOpenHelper = new DatabaseOpenHelper(context, DB_NAME, null, 1);
}

   public void open() throws SQLException 
   {
      //open database in reading/writing mode
      database = dbOpenHelper.getWritableDatabase();
   } 

   public void close() 
   {
      if (database != null)
         database.close();
   }       

   public void insertContact(String name, String cap, String code, String  
    LocationEd, String Notes, String Person,byte[] image) 
           {
              ContentValues newCon = new ContentValues();
              newCon.put("name", name);
              newCon.put("cap", cap);
              newCon.put("code", code);

              newCon.put("Location",LocationEd);
              newCon.put("Notes",Notes);
              newCon.put("Person",Person);
              newCon.put("Image", image);

              open();
              database.insert("country", null, newCon);
              close();
           }


           public void updateContact(long id, String name, String  
   cap,String code,String LocationEd, String Notes, String Person ,byte[] image) 
           {
              ContentValues editCon = new ContentValues();
              editCon.put("name", name);
              editCon.put("cap", cap);
              editCon.put("code", code);
              editCon.put("Location", LocationEd);
              editCon.put("Notes", Notes);
              editCon.put("Person", Person);
              editCon.put("Image", image);

              open();
              database.update("country", editCon, "_id=" + id, null);
              close();
           }


           public Cursor getAllContacts() 
           {
              return database.query("country", new String[] {"_id",  
       "name"}, 
                 null, null, null, null, "name");
           }

           public Cursor getOneContact(long id) 
           {
              return database.query("country", null, "_id=" + id, null,  
    null, null, null);
           }

           public void deleteContact(long id) 
           {
              open(); 
              database.delete("country", "_id=" + id, null);
              close();
           }
     }







        import android.content.Context;
    import android.database.sqlite.SQLiteDatabase;
     import android.database.sqlite.SQLiteDatabase.CursorFactory;
    import android.database.sqlite.SQLiteOpenHelper;

      public class DatabaseOpenHelper extends SQLiteOpenHelper {

public DatabaseOpenHelper(Context context, String name,
        CursorFactory factory, int version) {
    super(context, name, factory, version);
}

@Override
public void onCreate(SQLiteDatabase db) {
    String createQuery = "CREATE TABLE country (_id integer primary key   
     autoincrement,name text,cap text,code text,Location double,Notes text,Person  
      text,Image Blob);";              
    db.execSQL(createQuery);        
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

   }







       public class ViewCountry extends Activity {

   private long rowID;
   private TextView nameTv;
   private TextView capTv;
   private TextView codeTv; 


   private TextView Locationlb; 
   private TextView Noteslb; 
   private TextView Personlb; 



   private  ImageView imageView2;


   @Override
   public void onCreate(Bundle savedInstanceState) 
   {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.view_country);

      setUpViews();
      Bundle extras = getIntent().getExtras();
      rowID = extras.getLong(CountryList.ROW_ID); 
   }

   private void setUpViews() {
       nameTv = (TextView) findViewById(R.id.nameText);
       capTv = (TextView) findViewById(R.id.capText);
       codeTv = (TextView) findViewById(R.id.codeText);

       Locationlb = (TextView) findViewById(R.id.Location_lbl);



       Noteslb = (TextView) findViewById(R.id.Notes_lbl);
       Personlb = (TextView) findViewById(R.id.Person_lbl);


       imageView2= (ImageView) findViewById(R.id.imageView2);
          Button Browse2 = (Button) findViewById(R.id.Browse2);






          Browse2.setOnClickListener(new View.OnClickListener() 
            {
                public void onClick(View v) 
                {               
                    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                    intent.setType("image/*");
                    startActivityForResult(intent, 0);
                }
            });        























   }

   @Override
   protected void onResume()
   {
      super.onResume();
      new LoadContacts().execute(rowID);
   } 

   private class LoadContacts extends AsyncTask<Long, Object, Cursor> 
   {
      DatabaseConnector dbConnector = new DatabaseConnector(ViewCountry.this);

      @Override
      protected Cursor doInBackground(Long... params)
      {
         dbConnector.open();
         return dbConnector.getOneContact(params[0]);
      } 

      @Override
      protected void onPostExecute(Cursor result)
      {
         super.onPostExecute(result);

         result.moveToFirst();
         // get the column index for each data item
         int nameIndex = result.getColumnIndex("name");
         int capIndex = result.getColumnIndex("cap");
         int codeIndex = result.getColumnIndex("code");

         int LocationIndex = result.getColumnIndex("Location");
         int NotesIndex = result.getColumnIndex("Notes");
         int PersonIndex = result.getColumnIndex("Person");





         nameTv.setText(result.getString(nameIndex));
         capTv.setText(result.getString(capIndex));
         codeTv.setText(result.getString(codeIndex));
         Locationlb.setText(result.getString(LocationIndex));


         Noteslb.setText(result.getString(NotesIndex));
         Personlb.setText(result.getString(PersonIndex));




         result.close();
         dbConnector.close();
      }
   } 


   @Override
   public boolean onCreateOptionsMenu(Menu menu) 
   {
      super.onCreateOptionsMenu(menu);
      MenuInflater inflater = getMenuInflater();
      inflater.inflate(R.menu.view_country_menu, menu);
      return true;
   }

   @Override
   public boolean onOptionsItemSelected(MenuItem item) 
   {
      switch (item.getItemId())
      {
         case R.id.editItem:
            Intent addEditContact =
               new Intent(this, AddEditCountry.class);

            addEditContact.putExtra(CountryList.ROW_ID, rowID);
            addEditContact.putExtra("name", nameTv.getText());
            addEditContact.putExtra("cap", capTv.getText());
            addEditContact.putExtra("code", codeTv.getText());

            addEditContact.putExtra("Location", Locationlb.getText());


            addEditContact.putExtra("Notes", Noteslb.getText());

            addEditContact.putExtra("Person", Personlb.getText());

            startActivity(addEditContact); 
            return true;

         case R.id.deleteItem:
            deleteContact();
            return true;

         default:
            return super.onOptionsItemSelected(item);
      } 
   }

   private void deleteContact()
   {

      AlertDialog.Builder alert = new AlertDialog.Builder(ViewCountry.this);

      alert.setTitle(R.string.confirmTitle); 
      alert.setMessage(R.string.confirmMessage); 

      alert.setPositiveButton(R.string.delete_btn,
         new DialogInterface.OnClickListener()
         {
            public void onClick(DialogInterface dialog, int button)
            {
               final DatabaseConnector dbConnector = 
                  new DatabaseConnector(ViewCountry.this);

               AsyncTask<Long, Object, Object> deleteTask =
                  new AsyncTask<Long, Object, Object>()
                  {
                     @Override
                     protected Object doInBackground(Long... params)
                     {
                        dbConnector.deleteContact(params[0]); 
                        return null;
                     } 

                     @Override
                     protected void onPostExecute(Object result)
                     {
                        finish(); 
                     }
                  };

               deleteTask.execute(new Long[] { rowID });               
            }
         }
      );

      alert.setNegativeButton(R.string.cancel_btn, null).show();
    }
        }

Answer 1

我建议将图像的URL存储在数据库中，而不是将实际的图像存储为BLOB格式，因为以BLOB格式存储在数据库中的所有图像都将消耗内部存储器。

您可以稍后以延迟加载方式下载图像，然后将其缓存到SD卡中。您可以参考this发帖。

祝你好运：）