问题
Hello stackoverflow I'm trying to develop an application that display images from SD card and allow user to delete the images using a check box. I'm able to display images from SD card with CheckBox but I'm unable to delete the specific image which has been ticked by the user dynamically. Here is my MainActivity.java
public class MainActivity extends Activity {
private int count;
private Bitmap[] thumbnails;
private boolean[] thumbnailsselection;
private String[] arrPath;
private ImageAdapter imageAdapter;
ArrayList<String> f = new ArrayList<String>();// list of file paths
File[] listFile;
Button btnDelete;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getFromSdcard();
GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
imageAdapter = new ImageAdapter();
imagegrid.setAdapter(imageAdapter);
imageAdapter.notifyDataSetChanged();
btnDelete = (Button) findViewById(R.id.btnDeleteImg);
btnDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// to delete selected images
}
});
}
public void getFromSdcard() {
File file = new File("/mnt/sdcard/Images");
if (file.isDirectory()) {
listFile = file.listFiles();
for (int i = 0; i < listFile.length; i++) {
f.add(listFile[i].getAbsolutePath());
}
}
}
public class ImageAdapter extends BaseAdapter {
private LayoutInflater mInflater;
public ImageAdapter() {
mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
return f.size();
}
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);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
Bitmap myBitmap = BitmapFactory.decodeFile(f.get(position));
holder.imageview.setImageBitmap(myBitmap);
return convertView;
}
}
class ViewHolder {
ImageView imageview;
}
}
My activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF"
android:orientation="vertical" >
<GridView
android:id="@+id/PhoneImageGrid"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="0.97"
android:columnWidth="90sp"
android:gravity="center"
android:horizontalSpacing="10sp"
android:numColumns="auto_fit"
android:stretchMode="columnWidth"
android:verticalSpacing="10sp" />
<RelativeLayout
android:id="@+id/rlBookmark"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#ffffff"
android:layout_gravity="bottom" >
<Button
android:id="@+id/btnBookmark"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:text="Clear"
android:textColor="#FF0011"
android:textSize="15sp"
android:textStyle="normal" />
</RelativeLayout>
</LinearLayout>
and finally my galleryitem.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageView
android:id="@+id/thumbImage"
android:layout_width="100sp"
android:layout_height="100sp" />
<CheckBox
android:id="@+id/itemCheckBox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true" />
</RelativeLayout>
Please help me to solve this riddle, thanks in advance stackoverflow.
回答1:
You can refer to this example Images with checkbox and on click of delete button get the image name and perform delete operation like this:
File file= new File(Environment.getExternalStorageDirectory()+ "imageName");
if(file.exists())
{
file.delete();
}
回答2:
Hi stackoverflow finally i figured out how to delete multiple images using CheckBox in a GridView
public class MainActivity extends Activity {
private int count;
private Bitmap[] thumbnails;
private boolean[] thumbnailsselection;
private String[] arrPath;
private ImageAdapter imageAdapter;
ArrayList<String> f = new ArrayList<String>();// list of file paths
File[] listFile;
Button btnDelete;
private ProgressDialog pd;
HashSet<String> selectedFile = new HashSet<String>();// list of file paths boolean checked
GridView imagegrid;
AlertDialog alertDialog = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getFromSdcard();
imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
imageAdapter = new ImageAdapter();
imagegrid.setAdapter(imageAdapter);
imageAdapter.notifyDataSetChanged();
btnDelete = (Button) findViewById(R.id.btnDeleteImg);
btnDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// to delete selected images
}
});
}
public void getFromSdcard() {
File file = new File("/mnt/sdcard/Images");
if (file.isDirectory()) {
listFile = file.listFiles();
for (int i = 0; i < listFile.length; i++) {
f.add(listFile[i].getAbsolutePath());
}
}
}
public class ImageAdapter extends BaseAdapter {
private LayoutInflater mInflater;
public ImageAdapter() {
mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
return f.size();
}
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();
}
Bitmap myBitmap = BitmapFactory.decodeFile(f.get(position));
holder.imageview.setImageBitmap(myBitmap);
final int pos = position;
holder.checkbox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(!selectedFile.contains((String)f.get(pos)))
{
selectedFile.add((String)f.get(pos));
}
else
{
selectedFile.remove((String)f.get(pos));
}
}
});
return convertView;
}
}
class ViewHolder {
ImageView imageview;
CheckBox checkbox;
int id;
}
}
This approach is working for me, if you guys need more information please comment, Thanks stackoverflow
来源：https://stackoverflow.com/questions/17802085/how-to-delete-multiple-images-in-gridview-using-a-button-in-android