我正在尝试在自定义列表视图中添加文件夹中包含的所有图像，其中我显示了照片的缩略图和一些描述。 我发现很多示例都显示Android Studio中的URL或drawable文件夹中的图像，但是没有任何内容可以加载位于/storage/emulated/0/DCIM/Camera/AAAAMMGG_HHMMSS.jpg中的图片
这是我的代码 - MainActivity：
import android.content.ContentValues;
public class MainActivity extends ActionBarActivity implements OnClickListener {
public int PHOTO_REQUEST_CODE = 1;
private Uri fileUri;
private ArrayAdapter<String> adapter;
TextView ceScanResults;
ImageButton btnScan;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set a toolbar to replace the action bar.
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
View addButton = findViewById(mci);
ArrayList<ListItem> listData = getListData();
final ListView listView = (ListView) findViewById(R.id.custom_list);
listView.setAdapter(new CustomListAdapter(this, listData));
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
ListItem newsData = (ListItem) listView.getItemAtPosition(position);
Toast.makeText(MainActivity.this, "Selected :" + " " + newsData, Toast.LENGTH_LONG).show();
}
});
initViews();
}
private ArrayList<ListItem> getListData() {
ArrayList<ListItem> listMockData = new ArrayList<ListItem>();
String[] images = getResources().getStringArray(R.array.images_array);
String[] headlines = getResources().getStringArray(R.array.headline_array);
for (int i = 0; i < images.length; i++) {
ListItem newsData = new ListItem();
newsData.setUrl(images[i]);
newsData.setHeadline(headlines[i]);
newsData.setReporterName("CE code");
newsData.setDate("28/07/2015 - 10:31");
listMockData.add(newsData);
}
return listMockData;
}
private void initViews() {
//ceScanResults = (TextView) findViewById(R.id.ceResults);
btnScan = (ImageButton) findViewById(R.id.mci);
btnScan.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
//getMenuInflater().inflate(R.menu.main, menu);
return true;
}
private void initGalleryFetchImage() {
Intent i = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, RESULT_OK);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
Uri selectedImageUri = null;
String filePath = null;
if (requestCode == 1 && resultCode == RESULT_OK ) {
Uri selectedImage = intent.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
try {
Bitmap bmp = BitmapFactory.decodeStream(getContentResolver()
.openInputStream(selectedImage));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (resultCode == RESULT_OK) {
if (requestCode == 1) {
if (resultCode == RESULT_OK) {
//use imageUri here to access the image
selectedImageUri = fileUri;
} else if (resultCode == RESULT_CANCELED) {
Toast.makeText(this, "Picture was not taken", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Picture was not taken", Toast.LENGTH_SHORT).show();
}
} else if (requestCode == 2) {
selectedImageUri = intent.getData();
}
if(selectedImageUri != null){
try {
// OI FILE Manager
String filemanagerstring = selectedImageUri.getPath();
// MEDIA GALLERY
String selectedImagePath = getPath(selectedImageUri);
if (selectedImagePath != null) {
filePath = selectedImagePath;
} else if (filemanagerstring != null) {
filePath = filemanagerstring;
} else {
Toast.makeText(getApplicationContext(), "Unknown path",
Toast.LENGTH_LONG).show();
Log.e("Bitmap", "Unknown path");
}
if (filePath != null) {
decodeFile(filePath);
} else {
// bitmap = null;
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Internal error",
Toast.LENGTH_LONG).show();
Log.e(e.getClass().getName(), e.getMessage(), e);
}
}
}
}
public String getPath(Uri uri) {
String res = null;
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(uri, proj, null, null, null);
if(cursor.moveToFirst()){;
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
res = cursor.getString(column_index);
}
cursor.close();
return res;
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.mci) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(intent, PHOTO_REQUEST_CODE);
String fileName = "new-photo-name.jpg";
//create parameters for Intent with filename
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.TITLE, fileName);
values.put(MediaStore.Images.Media.DESCRIPTION,"Image captured by camera");
//imageUri is the current activity attribute, define and save it for later usage (also in onSaveInstanceState)
//create new Intent
startActivityForResult(intent, 1);
fileUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
}
}
public void decodeFile(String filePath) {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
try ( InputStream is = new URL(filePath).openStream() ) {
Bitmap bitmap = BitmapFactory.decodeStream( is );
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// The new size we want to scale to
final int REQUIRED_SIZE = 1024;
// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
}
}
我的CustomListAdapter的代码：
public class CustomListAdapter extends BaseAdapter {
private ArrayList<ListItem> listData;
private LayoutInflater layoutInflater;
public CustomListAdapter(Context context, ArrayList<ListItem> listData) {
this.listData = listData;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return listData.size();
}
@Override
public Object getItem(int position) {
return listData.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.list_row_layout, null);
holder = new ViewHolder();
holder.headlineView = (TextView) convertView.findViewById(R.id.title);
holder.reporterNameView = (TextView) convertView.findViewById(R.id.reporter);
holder.reportedDateView = (TextView) convertView.findViewById(R.id.date);
holder.imageView = (ImageView) convertView.findViewById(R.id.thumbImage);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
ListItem newsItem = listData.get(position);
holder.headlineView.setText(newsItem.getHeadline());
holder.reporterNameView.setText("" + newsItem.getReporterName());
holder.reportedDateView.setText(newsItem.getDate());
if (holder.imageView != null) {
new ImageDownloaderTask(holder.imageView).execute(newsItem.getUrl());
}
return convertView;
}
static class ViewHolder {
TextView headlineView;
TextView reporterNameView;
TextView reportedDateView;
ImageView imageView;
}
}
My class ImageDownloaderTask:
class ImageDownloaderTask extends AsyncTask<String, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
public ImageDownloaderTask(ImageView imageView) {
imageViewReference = new WeakReference<ImageView>(imageView);
}
@Override
protected Bitmap doInBackground(String... params) {
return downloadBitmap(params[0]);
}
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled()) {
bitmap = null;
}
if (imageViewReference != null) {
ImageView imageView = imageViewReference.get();
if (imageView != null) {
if (bitmap != null) {
imageView.setImageBitmap(bitmap);
} else {
Drawable placeholder = imageView.getContext().getResources().getDrawable(R.drawable.placeholder);
imageView.setImageDrawable(placeholder);
}
}
}
}
private Bitmap downloadBitmap(String url) {
HttpURLConnection urlConnection = null;
try {
URL uri = new URL(url);
urlConnection = (HttpURLConnection) uri.openConnection();
int statusCode = urlConnection.getResponseCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
InputStream inputStream = urlConnection.getInputStream();
if (inputStream != null) {
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
}
} catch (Exception e) {
urlConnection.disconnect();
Log.w("ImageDownloader", "Error downloading image from " + url);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
}
return null;
}
}
我的ListItem.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"
>
<ImageView
android:id="@+id/image"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_margin="5dp"
android:contentDescription="icon"
/>
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
/>
</LinearLayout>
非常感谢您的宝贵支持！ 问候， 米歇尔。
答案 0 :(得分：0)
我正在使用此库从URL加载图片
答案 1 :(得分：0)
尝试在适配器中使用这样的代码：
File img = new File("/sdcard/image.jpg");
if(img.exists()){
Bitmap bitmap = BitmapFactory.decodeFile(img.getAbsolutePath());
holder.imageView.setImageBitmap(bitmap);
}