我是Android的新手,我在应用程序上工作。我想下载一个图像并在列表项中显示它。我使用了很多功能。我的代码运行没有错误,但图像不会显示在我的代码的屏幕上。
public loader(Context context, String[] img) {
super(context, R.layout.item, img);
this.context = context;
this.img = img;
inflater = LayoutInflater.from(context);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// ImageView imgshow = (ImageView) findViewById(R.id.image1);
if (null == convertView) {
convertView = inflater.inflate(R.layout.item, parent, false);
}
ImageView imageView = (ImageView) convertView.findViewById(R.id.imageview);
//first method
// Glide.with(context)
// .load(img[position])
//.into(imageView);
//second method
DownloadImageTask download=new DownloadImageTask((ImageView) convertView.findViewById(R.id.imageview));
download.execute("http://previews.123rf.com/images/faysalfarhan/faysalfarhan1402/faysalfarhan140200008/25989999-Back-left-arrow-icon-glossy-purple-button-Stock-Photo.jpg");
//new DownloadImageTask((ImageView) convertView.findViewById(R.id.imageview))
//.execute(img[position]);
//third method
//Picasso.with(context).load(img[position]).into(imageView);
//Log.e("image_url","https://upload.wikimedia.org/wikipedia/commons/thumb/2/27/Square_200x200.svg/1024px-Square_200x200.svg.png");
return convertView;
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
TextView t;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = "http://previews.123rf.com/images/faysalfarhan/faysalfarhan1402/faysalfarhan140200008/25989999-Back-left-arrow-icon-glossy-purple-button-Stock-Photo.jpg";
Bitmap mIcon11 = null;
// Toast.makeText(mainpage.this ,urldisplay ,Toast.LENGTH_SHORT).show();
TextView t=(TextView)findViewById(R.id.texttt);
// t.setText(urldisplay);
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
}
我把它放在我的列表中使用(img是字符串数组我在其中保存url并显示它们但是为了测试我将它替换为loader类中的一个图像url)
String[] img = new String[1000];
loader im=new loader(mainpage.this,img);
lv.setAdapter(im);
答案 0 :(得分:0)
您无法直接在ImageView中设置图像。你必须在Bitmap中转换该图像,然后设置
public static Bitmap getBitmapFromURL(String src) {
try {
Log.e("src",src);
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
Log.e("Bitmap","returned");
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
Log.e("Exception",e.getMessage());
return null;
}
}
然后设置为imageview:
imageView.setImageBitmap(getBitmapFromURL(url));
试试希望它可以帮助你
答案 1 :(得分:0)
使用piccasso。
要使用piccasso添加它,请添加
compile 'com.squareup.picasso:picasso:2.5.2'
到您的应用级别gradle。和 使用这个
Picasso.with(context).load("http://previews.123rf.com/images/faysalfarhan/faysalfarhan1402/faysalfarhan140200008/25989999-Back-left-arrow-icon-glossy-purple-button-Stock-Photo.jpg").into(imageview);
或者你的getCount()方法返回0
。 (或添加它)将其更改为
@Override
public int getCount() {
return img.length;
}
答案 2 :(得分:0)
Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);
答案 3 :(得分:0)
使用Glide
glide的依赖:compile&#39; com.github.bumptech.glide:glide:3.7.0&#39;
并添加代码
db-server-preprod*