android - 如何从我的自定义图库中删除图像，然后刷新图库

Question

实际上我做了一个自定义图库。所有图片都显示在我的自定义图库中。但这里有一个问题。当使用删除按钮删除图像时，图像文件从内存中删除，但仍然显示图像(我的意思是缩略图仍然存在)。如何立即清除数据并刷新图库。

下面是我的代码

MainActivity.java

---

public class MainActivity extends Activity {
private int count;
private Bitmap[] thumbnails;
private boolean[] thumbnailsselection;
private String[] arrPath;
private ImageAdapter imageAdapter;
File file = null;


/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    show();

    final Button selectBtn = (Button) findViewById(R.id.selectBtn);
    final Button shareBtn = (Button) findViewById(R.id.btnShare);


    //delete image.
    selectBtn.setOnClickListener(new OnClickListener() {

        public void onClick(View v) 
        {
            final int len = thumbnailsselection.length;
            int cnt = 0;

            String selectImages = "";
            for (int i =0; i<len; i++)
            {
                if (thumbnailsselection[i])
                {
                    cnt++;
                    selectImages = selectImages + arrPath[i] +"   |   ";


                    file= new File(arrPath[i]);
                     if(file.exists())
                        {
                            file.delete();
                            Log.v("roni", selectImages);  
                            //arrPath[i] = null;
                            //selectImages = null;
                            Log.v("roni", arrPath[i]);
                        }


                }

            }
            if (cnt == 0){
                Toast.makeText(getApplicationContext(),
                        "Please select at least one image",
                        Toast.LENGTH_LONG).show();
            } else 
            {


                //thumbnails= null;



                show();


                Toast.makeText(getApplicationContext(),cnt +" Images Deleted ",Toast.LENGTH_LONG).show();
                Log.v("SelectedImages", selectImages);

            }

        }
    });

    //share image.
    shareBtn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            int id = v.getId();




            Intent shareIntent = new Intent();
            shareIntent.setAction(Intent.ACTION_SEND_MULTIPLE);

            final int len = thumbnailsselection.length;
            int cnt = 0;
            ArrayList<Uri> imageUris = new ArrayList<Uri>();
            Uri path= null;


            String selectImages = "";
            for (int i =0; i<len; i++)
            {
                if (thumbnailsselection[i])
                {
                    cnt++;
                    selectImages = selectImages + arrPath[i] +"   |   ";
                    Log.v("roni", selectImages);
                    path = Uri.parse(arrPath[i]);
                    imageUris.add(path);

                }
            }
            if (cnt == 0){
                Toast.makeText(getApplicationContext(),
                        "Please select at least one image",
                        Toast.LENGTH_LONG).show();
            } else 
            {

                Log.v("roni", selectImages);

                Toast.makeText(getApplicationContext(),cnt +" Images shared ",Toast.LENGTH_SHORT).show();
                Log.d("SelectedImages", selectImages);

            }

            shareIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, imageUris);
            shareIntent.setType("image/*");
            startActivity(Intent.createChooser(shareIntent, "Share images to.."));





            startActivity(shareIntent);
        }
    });

    show();
}


public void show() {

    //stored data
            final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
            final String orderBy = MediaStore.Images.Media._ID;


            Cursor imagecursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy);

            int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);

            this.count = imagecursor.getCount();
            this.thumbnails = new Bitmap[this.count];

            this.arrPath = new String[this.count];

            this.thumbnailsselection = new boolean[this.count];


            //move image
            for (int i = 0; i < this.count; i++) {
                imagecursor.moveToPosition(i);
                int id = imagecursor.getInt(image_column_index);
                int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
                thumbnails[i] = MediaStore.Images.Thumbnails.getThumbnail(getApplicationContext().getContentResolver(), id,
                        MediaStore.Images.Thumbnails.MINI_KIND, null);
                arrPath[i]= imagecursor.getString(dataColumnIndex);
            }
            GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);


            imageAdapter = new ImageAdapter();

            imagegrid.setAdapter(imageAdapter);

            imagecursor.close();


}

public class ImageAdapter extends BaseAdapter {
    private LayoutInflater mInflater;

    public ImageAdapter() {
        mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    public int getCount() {
        return count;
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = mInflater.inflate(R.layout.galleryitem, null);

            holder.imageview = (ImageView) convertView.findViewById(R.id.thumbImage);

            holder.checkbox = (CheckBox) convertView.findViewById(R.id.itemCheckBox);

            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.checkbox.setId(position);
        holder.imageview.setId(position);
        holder.checkbox.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {

                CheckBox cb = (CheckBox) v;
                int id = cb.getId();
                if (thumbnailsselection[id]){
                    cb.setChecked(false);
                    thumbnailsselection[id] = false;
                } else {
                    cb.setChecked(true);
                    thumbnailsselection[id] = true;
                }
            }
        });
        holder.imageview.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {

                int id = v.getId();
                /*Intent intent = new Intent();
                intent.setAction(Intent.ACTION_VIEW);
                intent.setDataAndType(Uri.parse("file://" + arrPath[id]), "image/*");
                startActivity(intent);
                */

                Intent intent = getIntent();
                Uri data = intent.getData();
                //Check If data type is Image
                if (intent.getType().indexOf("image/") == id)
                {
                    //imageview.setImageURI(data);
                    ImageView imge = (ImageView)findViewById(R.id.result);
                    imge.setImageURI(data);
                }
            }
        });
        holder.imageview.setImageBitmap(thumbnails[position]);
        holder.checkbox.setChecked(thumbnailsselection[position]);
        holder.id = position;
        return convertView;
    }
}
class ViewHolder {
    ImageView imageview;
    CheckBox checkbox;
    int id;
} }

---

Android Manifest 

---

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mygallary"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="21" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme"
    android:configChanges="orientation|keyboardHidden" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
            <data android:mimeType="image/*" />
        </intent-filter>

        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>

        <intent-filter>
              <action android:name="android.intent.action.VIEW" />

            <category android:name="android.intent.category.DEFAULT" />
            <data android:mimeType="image/*" />
        </intent-filter>
        <intent-filter>
              <action android:name="android.intent.action.SEND" />

            <data android:mimeType="image/*" />
        </intent-filter>
    </activity>

  </application>

---

修改代码后

---

public class MainActivity extends Activity {
    private int count;
    private Bitmap[] thumbnails;
    private boolean[] thumbnailsselection;
    private String[] arrPath;
    private ImageAdapter imageAdapter;
    File file = null;



    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        show();

        final Button selectBtn = (Button) findViewById(R.id.selectBtn);
        final Button shareBtn = (Button) findViewById(R.id.btnShare);


        //delete image.
        selectBtn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) 
            {
                final int len = thumbnailsselection.length;
                int cnt = 0;

                String selectImages = "";
                for (int i =0; i<len; i++)
                {
                    if (thumbnailsselection[i])
                    {
                        cnt++;
                        selectImages = selectImages + arrPath[i] +"   |   ";


                        file= new File(arrPath[i]);
                         if(file.exists())
                            {
                                file.delete();

                                imageAdapter.notifyDataSetChanged();
                                Log.v("roni", selectImages);  
                                //arrPath[i] = null;
                                //selectImages = null;
                                Log.v("roni", arrPath[i]);
                            }


                    }

                }
                if (cnt == 0){
                    Toast.makeText(getApplicationContext(),
                            "Please select at least one image",
                            Toast.LENGTH_LONG).show();
                } else 
                {


                    //thumbnails= null;


                    imageAdapter.notifyDataSetChanged();
                    show();


                    Toast.makeText(getApplicationContext(),cnt +" Images Deleted ",Toast.LENGTH_LONG).show();
                    Log.v("SelectedImages", selectImages);

                }

            }
        });

        //share image.
        shareBtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                int id = v.getId();




                Intent shareIntent = new Intent();
                shareIntent.setAction(Intent.ACTION_SEND_MULTIPLE);

                final int len = thumbnailsselection.length;
                int cnt = 0;
                ArrayList<Uri> imageUris = new ArrayList<Uri>();
                Uri path= null;


                String selectImages = "";
                for (int i =0; i<len; i++)
                {
                    if (thumbnailsselection[i])
                    {
                        cnt++;
                        selectImages = selectImages + arrPath[i] +"   |   ";
                        Log.v("roni", selectImages);
                        path = Uri.parse(arrPath[i]);
                        imageUris.add(path);

                    }
                }
                if (cnt == 0){
                    Toast.makeText(getApplicationContext(),
                            "Please select at least one image",
                            Toast.LENGTH_LONG).show();
                } else 
                {

                    Log.v("roni", selectImages);

                    Toast.makeText(getApplicationContext(),cnt +" Images shared ",Toast.LENGTH_SHORT).show();
                    Log.d("SelectedImages", selectImages);

                }

                shareIntent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, imageUris);
                shareIntent.setType("image/*");
                startActivity(Intent.createChooser(shareIntent, "Share images to.."));





                startActivity(shareIntent);
            }
        });

        show();
    }


    public void show() {

        //stored data
                final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
                final String orderBy = MediaStore.Images.Media._ID;


                Cursor imagecursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy);

                int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);

                this.count = imagecursor.getCount();
                this.thumbnails = new Bitmap[this.count];

                this.arrPath = new String[this.count];

                this.thumbnailsselection = new boolean[this.count];


                //move image
                for (int i = 0; i < this.count; i++) {
                    imagecursor.moveToPosition(i);
                    int id = imagecursor.getInt(image_column_index);
                    int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
                    thumbnails[i] = MediaStore.Images.Thumbnails.getThumbnail(getApplicationContext().getContentResolver(), id,
                            MediaStore.Images.Thumbnails.MINI_KIND, null);
                    arrPath[i]= imagecursor.getString(dataColumnIndex);
                }
                GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);


                imageAdapter = new ImageAdapter();

                imagegrid.setAdapter(imageAdapter);

                imagecursor.close();


    }

    public class ImageAdapter extends BaseAdapter {
        private LayoutInflater mInflater;

        public ImageAdapter() {
            mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

        public int getCount() {
            return count;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder;
            if (convertView == null) {
                holder = new ViewHolder();
                convertView = mInflater.inflate(R.layout.galleryitem, null);

                holder.imageview = (ImageView) convertView.findViewById(R.id.thumbImage);

                holder.checkbox = (CheckBox) convertView.findViewById(R.id.itemCheckBox);

                convertView.setTag(holder);
            }
            else {
                holder = (ViewHolder) convertView.getTag();
            }
            holder.checkbox.setId(position);
            holder.imageview.setId(position);
            holder.checkbox.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {

                    CheckBox cb = (CheckBox) v;
                    int id = cb.getId();
                    if (thumbnailsselection[id]){
                        cb.setChecked(false);
                        thumbnailsselection[id] = false;
                    } else {
                        cb.setChecked(true);
                        thumbnailsselection[id] = true;
                    }
                }
            });
            holder.imageview.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {

                    int id = v.getId();
                    /*Intent intent = new Intent();
                    intent.setAction(Intent.ACTION_VIEW);
                    intent.setDataAndType(Uri.parse("file://" + arrPath[id]), "image/*");
                    startActivity(intent);
                    */

                    /*Intent intent = getIntent();
                    Uri data = intent.getData();
                    //Check If data type is Image
                    if (intent.getType().indexOf("image/") == id)
                    {
                        //imageview.setImageURI(data);
                        ImageView imge = (ImageView)findViewById(R.id.result);
                        imge.setImageURI(data);
                    }*/
                }
            });
            holder.imageview.setImageBitmap(thumbnails[position]);
            holder.checkbox.setChecked(thumbnailsselection[position]);
            holder.id = position;
            return convertView;
        }
    }
    class ViewHolder {
        ImageView imageview;
        CheckBox checkbox;
        int id;
    }
}

Answer 1

在调用 notifyDataSetChanged(); 之前您应该从 thumbnails 中删除已删除的图像

您需要在自定义适配器中使用一个方法来执行此操作

我不知道如何删除 Bitmap[] 中的一项大批。但如果你可以使用 List<Bitmap>取而代之的是，该方法将是这样的:

public void RemoveThumbnail(int position)
{
    this.thumbnails.remove(position);
    //notifyDataSetChanged() can be called in this method or after
    //calling this method in MainActivity
    notifyDataSetChanged();
}

否则这是在特定位置删除缩略图的东西:

public void RemoveThumbnail(int position)
{
    Bitmap[] temp = new Bitmap[thumbnails.length - 1];
    int tempIndex = 0;
    for (int i = 0 ; i < thumbnails.lenght ; i++)
    {
        if(i != position)
            temp[tempIndex ++] = thumbnails[i];
    }
    thumbnails = temp;
    //notifyDataSetChanged() can be called in this method or after
    //calling this method in MainActivity
    notifyDataSetChanged();
}