我想从特定文件夹中检索图像到网格视图。 但我得到的imagelist值为null并被强制关闭。 我正在获取文件夹路径，但我收到了fileList
File[] imagelist = root.listFiles(new FilenameFilter(){
@Override
public boolean accept(File dir, String name)
{
return ((name.endsWith(".jpg"))||(name.endsWith(".png")));
}
});
我将listFiles视为null 它没有进入循环 任何人都可以帮助我PLZ
public class IleanaOffline extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.pics);
GridView grid=(GridView)findViewById(R.id.gridView1);
File root = new File(Environment.getExternalStorageDirectory()
+ File.separator + "Indian Actress" + File.separator + "Ileana" + File.separator);
File[] imagelist = root.listFiles(new FilenameFilter(){
@Override
public boolean accept(File dir, String name)
{
return ((name.endsWith(".jpg"))||(name.endsWith(".png")));
}
});
String[] mFiles = new String[imagelist.length];
for(int i= 0 ; i< imagelist.length; i++)
{
mFiles[i] = imagelist[i].getAbsolutePath();
}
Uri[] mUrls = new Uri[mFiles.length];
for(int i=0; i < mFiles.length; i++)
{
mUrls[i] = Uri.parse(mFiles[i]);
}
grid.setAdapter(new CustomAdapterOffline(mUrls,this));
}
}
任何人都可以向我建议我需要做的改变 THANKYOU
答案 0 :(得分：1)
enter code here
public class AndroidCustomGalleryActivity extends Activity {
private int count;
private Bitmap[] thumbnails;
private boolean[] thumbnailsselection;
private String[] arrPath;
private ImageAdapter imageAdapter;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
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];
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.MICRO_KIND, null);
arrPath[i]= imagecursor.getString(dataColumnIndex);
}
GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
imageAdapter = new ImageAdapter();
imagegrid.setAdapter(imageAdapter);
imagecursor.close();
final Button selectBtn = (Button) findViewById(R.id.HideBtn);
selectBtn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
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] + "|";
}
}
if (cnt == 0){
Toast.makeText(getApplicationContext(),
"Please select at least one image",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(),
"You've selected Total " + cnt + " image(s).",
Toast.LENGTH_LONG).show();
Log.d("SelectedImages", selectImages);
}
if (cnt > 1){
}
}
});
}
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) {
// TODO Auto-generated method stub
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) {
// TODO Auto-generated method stub
int id = v.getId();
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.parse("file://" + arrPath[id]), "image/*");
startActivity(intent);
}
});
holder.imageview.setImageBitmap(thumbnails[position]);
holder.checkbox.setChecked(thumbnailsselection[position]);
holder.id = position;
return convertView;
}
}
class ViewHolder {
ImageView imageview;
CheckBox checkbox;
int id;
}}
enter code here
Xml main
<?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">
<Button
android:id="@+id/HideBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:minWidth="200px"
android:text="Hide" />
<GridView android:id="@+id/PhoneImageGrid"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:numColumns="auto_fit" android:verticalSpacing="10dp"
android:horizontalSpacing="10dp" android:columnWidth="90dp"
android:stretchMode="columnWidth" android:gravity="center"
android:layout_above="@id/HideBtn" />
<Button
android:id="@+id/UnHideBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:minWidth="200px"
android:text="UnHide" />
</RelativeLayout>
enter code here
layout
<?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="wrap_content"
android:layout_height="wrap_content" android:layout_centerInParent="true" />
<CheckBox android:id="@+id/itemCheckBox" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:layout_alignParentRight="true"
android:layout_alignParentTop="true" />
</RelativeLayout>
答案 1 :(得分：0)
使用以下代码段从特定文件夹的SD卡获取图像
private List<String> ReadSDCardImages() {
ArrayList<String> fileList= new ArrayList<String>();
fileList.clear();
f = new File(Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/yourfolderName");
files = f.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return ((name.endsWith(".jpg")) || (name.endsWith(".png")));
}
});
for (int i = 0; i < files.length; i++) {
File file = files[i];
fileList.add(file.getPath());
}
return fileList;
}
从文件夹中传递所有图像后，将arraylist传递给ImageAdapter。 希望这会对你有所帮助。