Я создаю простое приложение с ImageView и GridView. Я загружаю изображения с интернет-ресурса. Приложение может отображать изображение (я тестировал с ImageView), но не может отображать все изображения в списке.
Я тестировал следующее:
- Класс
DownloadImage работалобычно. - С
ImageAdapter тоже все в порядке.
Однако изображения по-прежнему не могут быть загружены на GridView. Нет необходимости во внешних библиотеках (Picasso, Glide ...) .
Здесь activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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"
android:background="@color/colorPrimary"
tools:context=".MainActivity">
<GridView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:id="@+id/gridview"/>
</ScrollView>
Здесь DownloadImage.java
package com.example.imageviewer;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.widget.ImageView;
import java.io.InputStream;
import java.net.URL;
public class DownloadImage extends AsyncTask<String, Void, Bitmap> {
ImageView imageview;
public DownloadImage(ImageView imageview){
this.imageview = imageview;
}
@Override
protected Bitmap doInBackground(String... strings) {
String url = strings[0];
Bitmap result = null;
try{
InputStream in = new URL(url).openConnection().getInputStream();
result = BitmapFactory.decodeStream(in);
}catch(Exception e){
e.printStackTrace();
}
return result;
}
@Override
protected void onPostExecute(Bitmap bitmap) {
imageview.setImageBitmap(bitmap);
}
}
Вот ImageAdapter.java
package com.example.imageviewer;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
public class ImageAdapter extends BaseAdapter {
private Context context;
private String[] imagelist;
public ImageAdapter(Context context, String[] imagelist) {
this.context = context;
this.imagelist = imagelist;
}
@Override
public int getCount() {
return imagelist.length;
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imagview;
if(convertView==null)
imagview = new ImageView(context);
else
imagview = (ImageView)convertView;
new DownloadImage(imagview).execute(imagelist[position]);
return imagview;
}
}
Вот MainActivity.java
package com.example.imageviewer;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
public class MainActivity extends AppCompatActivity {
GridView gridview;
String[] urls = {
"https://sarahraven.images.blucommerce.com/sarahraven/product/261037_2.jpg",
"https://ngb.org/wp-content/uploads/2018/09/longfield.gardens.Sept_.jpg"
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridview = findViewById(R.id.gridview);
ImageAdapter imageadapter = new ImageAdapter(getApplicationContext(), urls);
gridview.setAdapter(imageadapter);
gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
}
});
}
}
Вот логкат:
10-11 08:41:27.040 10544-10544/? I/art: Not late-enabling -Xcheck:jni (already on)
10-11 08:41:27.458 10544-10544/com.example.imageviewer W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter androidx.vectordrawable.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
10-11 08:41:27.646 10544-10544/com.example.imageviewer I/art: Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>
10-11 08:41:27.669 10544-10544/com.example.imageviewer I/art: Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>
10-11 08:41:27.767 10544-10557/com.example.imageviewer I/art: Background sticky concurrent mark sweep GC freed 2403(236KB) AllocSpace objects, 0(0B) LOS objects, 22% free, 874KB/1135KB, paused 2.275ms total 159.898ms
10-11 08:41:28.360 10544-10563/com.example.imageviewer D/OpenGLRenderer: Render dirty regions requested: true
10-11 08:41:28.419 10544-10544/com.example.imageviewer D/Atlas: Validating map...
10-11 08:41:28.764 10544-10563/com.example.imageviewer I/OpenGLRenderer: Initialized EGL, version 1.4
10-11 08:41:28.833 10544-10563/com.example.imageviewer D/EGL_emulation: eglCreateContext: 0x7f8131b44740: maj 3 min 0 rcv 3
10-11 08:41:28.865 10544-10563/com.example.imageviewer D/EGL_emulation: eglMakeCurrent: 0x7f8131b44740: ver 3 0 (tinfo 0x7f8131b11260)
10-11 08:41:28.880 10544-10563/com.example.imageviewer E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008cdf
10-11 08:41:28.880 10544-10563/com.example.imageviewer E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008824
10-11 08:41:28.884 10544-10563/com.example.imageviewer D/OpenGLRenderer: Enabling debug mode 0
10-11 08:41:28.985 10544-10563/com.example.imageviewer D/EGL_emulation: eglMakeCurrent: 0x7f8131b44740: ver 3 0 (tinfo 0x7f8131b11260)
10-11 08:41:29.019 10544-10544/com.example.imageviewer I/Choreographer: Skipped 33 frames! The application may be doing too much work on its main thread.
Заранее спасибо!