我正在尝试从网址下载图片并将其保存在文件中。但它没有得到拯救。因此，当我调试代码时，我发现位图始终为空。
代码：
public class ImageUserTask extends AsyncTask<Void, Void,String> {
String strURL, imageprofile;
Bitmap mBitmap = null;
Context mContext;
private File profileFile;
public ImageUserTask(Context context, String url) {
this.strURL = url;
this.imageprofile = imageprofile;
this.mContext = context;
}
@Override
protected String doInBackground(Void... params) {
Bitmap bitmap = null;
File directory = null;
try {
URL url = new URL(strURL);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
// InputStream input = connection.getInputStream();
bitmap = BitmapFactory.decodeStream(url.openConnection().getInputStream()); //This bitmap is null always
directory = Environment.getExternalStorageDirectory();
// Create a new folder in SD Card
File dir = new File(Environment.getExternalStorageDirectory().getPath() + "/Profile");
if (!directory.exists() && !directory.isDirectory()) {
directory.mkdirs();
}
File mypath = new File(dir,"ProfileImage");
saveFile(mypath, bitmap);
} catch (MalformedURLException e) {
} catch (IOException e) {
}
return directory.getAbsolutePath();
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (result != null) {
imageprofile = result;
}
}
private void saveFile(File fileName, Bitmap bmp) {
FileOutputStream outputStream = null;
try {
outputStream = new FileOutputStream(fileName);
bmp.compress(Bitmap.CompressFormat.JPEG, 100, outputStream); // 100 will be ignored
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
编辑：
public class ImageUserTask extends AsyncTask<Void,Void,Bitmap> {
String strURL, imageprofile;
Bitmap mBitmap = null;
Context mContext;
private File profileFile;
public ImageUserTask(Context context, String url) {
this.strURL = url;
this.imageprofile = imageprofile;
this.mContext = context;
}
@Override
protected Bitmap doInBackground(Void... params) {
getImageFromUrl(strURL);
return mBitmap;
}
@Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
if (result != null) {
Bitmap bitmap = result;
}
}
public Bitmap getImageFromUrl(String urlString) {
try {
URL url = new URL(urlString);
try {
if(mBitmap!=null) {
mBitmap.recycle();
mBitmap=null;
}
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setDoInput(true);
//Connected to server
connection.connect();
//downloading image
InputStream input = connection.getInputStream();
mBitmap = BitmapFactory.decodeStream(input);
convertBitmapToFile(mBitmap, urlString);
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return mBitmap;
}
public File convertBitmapToFile(Bitmap bitmap, String fileName) {
ContextWrapper cw = new ContextWrapper(mContext);
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
File mypath = new File(directory, fileName);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
return mypath;
}
}
可能是什么原因？我也添加了Internet权限。请帮忙。谢谢..
答案 0 :(得分：0)
class DownloadFile extends AsyncTask<String, Integer, String> {
String strFolderName;
String shareType;
String downloadPath = "";
Activity mContext;
public DownloadFile(Activity mContext) {
this.mContext = mContext;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... aurl) {
int count;
try {
String fileName = "your filename with ext";
Log.d("TAG", fileName);
URL url = new URL("your url");
URLConnection conexion = url.openConnection();
conexion.connect();
String PATH = "your Path you want to store" + "/";
downloadPath = PATH + fileName;
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(downloadPath);
byte data[] = new byte[1024];
while ((count = input.read(data)) != -1) {
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String path) {
super.onPostExecute(path);
}
}
此代码适用于我
答案 1 :(得分：0)
使用以下方法
public Bitmap getImageFromUrl(String urlString) {
Bitmap bmp = null;
try {
URL url = new URL(urlString);
try {
if(bmp!=null) {
bmp.recycle();
bmp=null;
}
bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
convertBitmapToFile(bmp, urlString);
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
return bmp;
}
public File convertBitmapToFile(Bitmap bitmap, String fileName) {
ContextWrapper cw = new ContextWrapper(activityRef.getApplicationContext());
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
File mypath = new File(directory, fileName);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
return mypath;
}
为互联网和存储添加Android权限
答案 2 :(得分：0)
请试试这个
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;
}
}