0

我有下面的代码，它将从图库中挑选出的图像列表放入 GridView 布局。图片在 GridView 布局中显示得很好，但问题是当我关闭应用程序或从图库中选择不同的图片时，这些图片会消失。

有人能指出我正确的方向吗？

任何帮助将不胜感激。

代码：

public class MainActivity extends Activity {

   GridView gridGallery;
   Handler handler;
   Gallery_Adapter_Activity adapter;

   Button btnGalleryPick;
   Button btnGalleryPickMul;

   String action;
   ViewSwitcher viewSwitcher;
   ImageLoader imageLoader;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);

    initImageLoader();
    init();
}

private void initImageLoader() {
    @SuppressWarnings("deprecation")
    DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
            .cacheOnDisc().imageScaleType(ImageScaleType.EXACTLY_STRETCHED)
            .bitmapConfig(Bitmap.Config.RGB_565).build();
    ImageLoaderConfiguration.Builder builder = new ImageLoaderConfiguration.Builder(
            this).defaultDisplayImageOptions(defaultOptions).memoryCache(
            new WeakMemoryCache());

    ImageLoaderConfiguration config = builder.build();
    imageLoader = ImageLoader.getInstance();
    imageLoader.init(config);
}

private void init() {

    handler = new Handler();
    gridGallery = (GridView) findViewById(R.id.gridGallery);
    gridGallery.setFastScrollEnabled(true);                     
    adapter = new Gallery_Adapter_Activity(getApplicationContext(), imageLoader);
    adapter.setMultiplePick(false);
    gridGallery.setAdapter(adapter);

    viewSwitcher = (ViewSwitcher) findViewById(R.id.viewSwitcher);
    viewSwitcher.setDisplayedChild(1);


    Button done_button = (Button) findViewById(R.id.done);      
    done_button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {       
            finish();                           
        }                       
    });


    btnGalleryPickMul = (Button) findViewById(R.id.btnGalleryPickMul);
    btnGalleryPickMul.setOnClickListener(new View.OnClickListener() {                               

        @Override
        public void onClick(View v) {       //Add Images Button OnClickListener
            Intent i = new Intent(Multiple_Pick_Activity.ACTION_MULTIPLE_PICK);
            startActivityForResult(i, 12345);           
        }                           
    });

}

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

if (requestCode == result_requestcode && resultCode == Activity.RESULT_OK)

{       

SDcardPath_Activity SDcardPath_Class = new SDcardPath_Activity();

String[] ALL_Paths = data.getStringArrayExtra("all_path");

for (String single_path : ALL_Paths) 
{      

    SQ_LITE_DATABASE.addImageFile(single_path);           

}

try { 


ArrayList<SDcardPath_Activity> SQLite_Databse_Data = SQ_LITE_DATABASE.readImageFiles();
SQLite_Databse_Data.add(SDcardPath_Class);

viewSwitcher.setDisplayedChild(0);
adapter.addAll(SQLite_Databse_Data);        

Intent intent = new Intent (Image_MainActivity.this, Image_MainActivity.class);
startActivity(intent);
finish();

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

  }
 }       
}

编辑：发布上面的工作代码

4

3 回答 3

1

我建议您使用SQlite database可以存储图像路径的位置。
拍照时，将它们保存在SD卡中，并在数据库中记录它们的路径。
每次你开始你的活动迭代你的数据库，获取所有内容并填充你的 GridView。
SharedPreferences如果您不打算保存大量图像，那就太好了。

于 2014-05-14T02:53:55.473 回答
1

把这些放在你的 onActivityResult 中：

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

if (requestCode == result_requestcode && resultCode == Activity.RESULT_OK)

    {       

    SDcardPath_Activity SDcardPath_Class = new SDcardPath_Activity();

    String[] ALL_Paths = data.getStringArrayExtra("all_path");

    for (String single_path : ALL_Paths) 
    {      

        SQ_LITE_DATABASE.addImageFile(single_path);           

    }

 try { 


    ArrayList<SDcardPath_Activity> SQLite_Databse_Data = SQ_LITE_DATABASE.readImageFiles();
    SQLite_Databse_Data.add(SDcardPath_Class);

    viewSwitcher.setDisplayedChild(0);
    adapter.addAll(SQLite_Databse_Data);        

    Intent intent = new Intent (Image_MainActivity.this, Image_MainActivity.class);
    startActivity(intent);
    finish();

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

   }
  }       
 }
于 2014-06-04T12:34:59.747 回答
0

如果您需要在应用关闭时保留列表，则需要将列表存储到 SharedPreferences、数据库或文件中。

方法一：使用 SharedPreferences。

将所选文件保存到 SharedPreferences 

 // selectedFiles is Set<String> with all your selected files
 Set<String> selectedFiles = new HashSet<String>();

 // TODO put your selected file names into selectedFiles set

 SharedPreferences prefs = getSharedPreferences("prefs_selection", 0);
 SharedPreferences.Editor editor = prefs.edit();

 editor.putStringSet("selection", selectedFiles);

 // save
 editor.commit();

从 SharedPreferences 恢复选定的文件

SharedPreferences prefs = getSharedPreferences("prefs_selection", 0);

Set<String> selectedFiles = prefs.getStringSet("selection", null);
if (selectedFiles != null) {
    // TODO put elements of selectedFiles into appropriate your elements
}

方法二：使用SQLLiteDatabase。

定义派生自 SQLiteOpenHelper 的类。

public class ImagesOpenHelper extends SQLiteOpenHelper {

    private static final String KEY_IMAGE = "image_file";
    private static final String DATABASE_NAME = "imagesdb";
    private static final int DATABASE_VERSION = 1;
    private static final String IMAGES_TABLE_NAME = "images";
    private static final String IMAGES_TABLE_CREATE =
            "CREATE TABLE " + IMAGES_TABLE_NAME + " (" +
            KEY_IMAGE + " TEXT);";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(IMAGES_TABLE_CREATE);
    }

    public void addImageFile(String file) {
        ContentValues values = new ContentValues();
        values.put(KEY_IMAGE, file);

        getWritableDatabase().insert(IMAGES_TABLE_NAME, null, values);
    }

    public void readImageFiles() {
        Cursor cursor = getReadableDatabase().query(IMAGES_TABLE_NAME, new String[] { KEY_IMAGE }, null, null, null, null, null, null);

        try {
            if (!cursor.moveToFirst())
                return ; 

            ArrayList<SDcardPath_Activity> Picture_List = new ArrayList<SDcardPath_Activity>();

            do {
                String file = cursor.getString(0);

                SDcardPath_Activity PICTURE = new SDcardPath_Activity();
                PICTURE.sdcardPath = file;
                Picture_List.add(PICTURE);

            } while (cursor.moveToNext());

            viewSwitcher.setDisplayedChild(0);
            adapter.addAll(Picture_List);
        }
        finally {
            cursor.close();
        }
    }
}

在活动的 onCreate 中创建此类的对象。调用 readImageFiles() 读取图像文件路径。调用 addImageFile(String file) 将图像文件路径添加到数据库中。

在 ImageLoader imageLoader 行之后添加以下行：

ImagesOpenHelper imagesOpenHelper;

添加到 onCreate

imagesOpenHelper = new ImagesOpenHelper(this);
imagesOpenHelper.readImageFiles();

在 onActivityResult 中，将以下行添加到 for 循环中：

imagesOpenHelper.addImageFile(string);
于 2014-05-14T02:46:52.177 回答