工作解决方案的帮助下Glide。额外的部分是 Glide 会自动播放 Gif。
import java.util.ArrayList;
import android.app.Activity;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.provider.MediaStore.MediaColumns;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
import com.bumptech.glide.Glide;
/**
* The Class GallarySample.
*/
public class GallarySample extends Activity {
/** The images. */
private ArrayList<String> images;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gallery_activity);
GridView gallery = (GridView) findViewById(R.id.galleryGridView);
gallery.setAdapter(new ImageAdapter(this));
gallery.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
if (null != images && !images.isEmpty())
Toast.makeText(
getApplicationContext(),
"position " + position + " " + images.get(position),
300).show();
;
}
});
}
/**
* The Class ImageAdapter.
*/
private class ImageAdapter extends BaseAdapter {
/** The context. */
private Activity context;
/**
* Instantiates a new image adapter.
*
* @param localContext
* the local context
*/
public ImageAdapter(Activity localContext) {
context = localContext;
images = getAllShownImagesPath(context);
}
public int getCount() {
return images.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(final int position, View convertView,
ViewGroup parent) {
ImageView picturesView;
if (convertView == null) {
picturesView = new ImageView(context);
picturesView.setScaleType(ImageView.ScaleType.FIT_CENTER);
picturesView
.setLayoutParams(new GridView.LayoutParams(270, 270));
} else {
picturesView = (ImageView) convertView;
}
Glide.with(context).load(images.get(position))
.placeholder(R.drawable.ic_launcher).centerCrop()
.into(picturesView);
return picturesView;
}
/**
* Getting All Images Path.
*
* @param activity
* the activity
* @return ArrayList with images Path
*/
private ArrayList<String> getAllShownImagesPath(Activity activity) {
Uri uri;
Cursor cursor;
int column_index_data, column_index_folder_name;
ArrayList<String> listOfAllImages = new ArrayList<String>();
String absolutePathOfImage = null;
uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
String[] projection = { MediaColumns.DATA,
MediaStore.Images.Media.BUCKET_DISPLAY_NAME };
cursor = activity.getContentResolver().query(uri, projection, null,
null, null);
column_index_data = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
column_index_folder_name = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
while (cursor.moveToNext()) {
absolutePathOfImage = cursor.getString(column_index_data);
listOfAllImages.add(absolutePathOfImage);
}
return listOfAllImages;
}
}
}
gridView 的布局文件
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<GridView
android:id="@+id/galleryGridView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:columnWidth="280dp"
android:gravity="center"
android:horizontalSpacing="2dp"
android:numColumns="2"
android:padding="2dp"
android:stretchMode="columnWidth"
android:verticalSpacing="2dp" >
</GridView>
</RelativeLayout>
2019 年更新为Kotlin and LoderManager:
** 2) 使用LoderManager加载异步加载图片。**
实施LoaderManager.LoaderCallbacks<Cursor>在您的 Activity 或 Fragment 类中
重写 LoaderCallbacks：
private val IMAGE_LOADER_ID = 1
private val listOfAllImages = ArrayList<String>()
override fun onCreateLoader(p0: Int, p1: Bundle?): Loader<Cursor> {
val uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
val projection = arrayOf(MediaColumns.DATA, MediaStore.Images.Media.BUCKET_DISPLAY_NAME)
val selection: String? = null //Selection criteria
val selectionArgs = arrayOf<String>() //Selection criteria
val sortOrder: String? = null
return CursorLoader(
activity!!.applicationContext,
uri,
projection,
selection,
selectionArgs,
sortOrder)
}
override fun onLoadFinished(loader: Loader<Cursor>, cursor: Cursor?) {
cursor?.let {
val columnIndexData = it.getColumnIndexOrThrow(MediaColumns.DATA);
while (it.moveToNext()) {
listOfAllImages.add(it.getString(columnIndexData));
}
}
}
override fun onLoaderReset(loader: Loader<Cursor>) {
}
最后在 onCreate 方法初始化加载器上：
loaderManager.initLoader(IMAGE_LOADER_ID,
null,
this)
3）使用Kotlin Coroutine & ViewModel
实现 'androidx.core:core-ktx:1.0.2'
实现 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.0-M2'
实现“org.jetbrains.kotlinx：kotlinx-coroutines-android：1.3.0-M2”
创建视图模型Coroutine Context
/**
* Use Coroutines To Load Images
*/
class ImageViewModel : ViewModel(), CoroutineScope {
private val job = Job()
override val coroutineContext: CoroutineContext
get() = job + Dispatchers.Main
private var imagesLiveData: MutableLiveData<List<String>> = MutableLiveData()
fun getImageList(): MutableLiveData<List<String>> {
return imagesLiveData
}
/**
* Getting All Images Path.
*
* Required Storage Permission
*
* @return ArrayList with images Path
*/
internal fun loadImagesfromSDCard(): ArrayList<String> {
val uri: Uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI
val cursor: Cursor?
val column_index_data: Int
val column_index_folder_name: Int
val listOfAllImages = ArrayList<String>()
var absolutePathOfImage: String? = null
val projection = arrayOf(MediaStore.MediaColumns.DATA, MediaStore.Images.Media.BUCKET_DISPLAY_NAME)
cursor = AppController.globalContentResolvere!!.query(uri, projection, null, null, null)
column_index_data = cursor!!.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA)
column_index_folder_name = cursor!!
.getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME)
while (cursor!!.moveToNext()) {
absolutePathOfImage = cursor!!.getString(column_index_data)
listOfAllImages.add(absolutePathOfImage)
}
return listOfAllImages
}
fun getAllImages() {
launch(Dispatchers.Main) {
imagesLiveData.value = withContext(Dispatchers.IO) {
loadImagesfromSDCard()
}
}
}
}
然后使用viewModel
val imageViewModel = ViewModelProviders.of(this).get(ImageViewModel::class.java)
imageViewModel.getImageList().observe(this, Observer<List<String>> { listOfImage ->
imageWidgetStatus.text = """ Found ${listOfImage.size} Images"""
// load images
imageViewModel.getAllImages()
