我试图从设备库（而不是SD卡）导入所有图像但没有成功。我正在使用权限功能来使用外部存储。在我确认许可后，什么也没发生。任何人都可以帮忙我错了吗？
import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.provider.MediaStore;
import android.support.annotation.RequiresApi;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
public class ImagesSelect extends AppCompatActivity {
private static final int SELECT_PICTURE = 1;
private String selectedImagePath;
private Cursor cursor;
private int columnIndex;
private static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 1;
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_images_select);
if (ContextCompat.checkSelfPermission(ImagesSelect.this, Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(
ImagesSelect.this, Manifest.permission.READ_EXTERNAL_STORAGE)) {
// Explain to the user why we need to read the contacts
}
else{
ActivityCompat.requestPermissions(ImagesSelect.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults)
{
switch (requestCode){
case MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:{
if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
String[] projection = new String[] {
MediaStore.Images.Media._ID,
MediaStore.Images.Media.BUCKET_DISPLAY_NAME,
MediaStore.Images.Media.DATE_TAKEN
};
Uri images = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
cursor = getContentResolver().query(images,
projection,
null,
null,
null
);
if (cursor.moveToFirst()) {
String bucket;
String date;
int bucketColumn = cursor.getColumnIndex(
MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
int dateColumn = cursor.getColumnIndex(
MediaStore.Images.Media.DATE_TAKEN);
do {
bucket = cursor.getString(bucketColumn);
date = cursor.getString(dateColumn);
//Log.i("ListingImages", " bucket=" + bucket + " date_taken=" + date);
GridView galleryGV = (GridView) findViewById(R.id.imagesGridView);
galleryGV.setAdapter(new ImageAdapter(this));
} while (cursor.moveToNext());
}
}
else
{
}
return;
}
}
}
public class ImageAdapter extends BaseAdapter {
private Context context;
public ImageAdapter(Context localContext){
context = localContext;
}
public int getCount() {
return cursor.getCount();
}
public Object getItem(int position){
return position;
}
public long getItemId(int position){
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
imageView = new ImageView(context);
cursor.moveToPosition(position);
int imageID = cursor.getInt(columnIndex);
imageView.setLayoutParams(new GridView.LayoutParams(100, 100));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
return imageView;
}
}
}