如何从android中的url获取位图？
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How to get bitmap from a url in android?
提问by Chandra Sekhar
I have a uri like which has an image
我有一个像 uri 这样的图像
file:///mnt/...............
How to use this uri to get the image but it returns null, please tell me where i am wrong.
如何使用这个uri获取图像但它返回null，请告诉我我错在哪里。
Bitmap bitmap = BitmapFactory.decodeFile(uri.getPath());
Bitmap bitmap = BitmapFactory.decodeFile(uri.toString());
回答by brthornbury
This is a simple one line way to do it:
这是一种简单的单行方式：
try {
URL url = new URL("http://....");
Bitmap image = BitmapFactory.decodeStream(url.openConnection().getInputStream());
} catch(IOException e) {
System.out.println(e);
}
回答by Luke Taylor
This should do the trick:
这应该可以解决问题：
public static Bitmap getBitmapFromURL(String src) {
try {
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
} // Author: silentnuke
Don't forget to add the internet permission in your manifest.
不要忘记在清单中添加互联网权限。
回答by brthornbury
Okay so you are trying to get a bitmap from a file? Title says URL. Anyways, when you are getting files from external storage in Android you should never use a direct path. Instead call getExternalStorageDirectory() like so:
好的，所以您正在尝试从文件中获取位图？标题表示 URL。无论如何，当您从 Android 中的外部存储获取文件时，您永远不应该使用直接路径。而是像这样调用 getExternalStorageDirectory() ：
File bitmapFile = new File(Environment.getExternalStorageDirectory() + "/" + PATH_TO_IMAGE);
Bitmap bitmap = BitmapFactory.decodeFile(bitmapFile);
getExternalStorageDirectory() gives you the path to the SD card. Also you need to declare the WRITE_EXTERNAL_STORAGE permission in the Manifest.
getExternalStorageDirectory() 为您提供 SD 卡的路径。您还需要在 Manifest 中声明 WRITE_EXTERNAL_STORAGE 权限。
