答案 0 :(得分:0)
尝试查看此tutorial,对我非常有帮助。他使用名为ImageLoader
的自定义类和公共方法DisplayImage(String url, int loader, ImageView imageView)
,您可以这样调用它:
int loader = R.drawable.loader;
// Imageview to show
ImageView image = (ImageView) findViewById(R.id.image);
// Image url
String image_url = "http://www.example.com/images/sample.jpg";
// ImageLoader class instance
ImageLoader imgLoader = new ImageLoader(getApplicationContext());
imgLoader.DisplayImage(image_url, loader, image);
答案 1 :(得分:0)
这没什么难的。
公共类DownloadImage扩展了Activity {
String image_URL=http://www.hdwallpapers.in/download/minions_2015-1280x720.jpg; // give image name to save in sd card
String extStorageDirectory;
String sdCard;
Bitmap bitmap;
File file;
String savedFilePath;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button buttonSave = (Button)findViewById(R.id.save);
ImageView bmImage = (ImageView)findViewById(R.id.image);
buttonSave.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
myAsyncTask myWebFetch = new myAsyncTask();
myWebFetch.execute();
}
});
}
class myAsyncTask extends AsyncTask<Void, Void, Void> {
TextView tv;
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
dialog.dismiss();
}
@Override
protected void onPreExecute() {
super.onPreExecute();
public ProgressDialog dialog;
dialog = new ProgressDialog(DownloadImage.this);
dialog.setMessage("Loading...");
dialog.setCancelable(false);
dialog.setIndeterminate(true);
dialog.show();
}
protected Void doInBackground(Void... arg0) {
try {
//set the download URL, a url that points to a file on the internet
//this is the file to be downloaded
URL url = new URL(image_URL);
//create the new connection
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//set up some things on the connection
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//and connect!
urlConnection.connect();
//set the path where we want to save the file
//in this case, going to save it on the root directory of the
//sd card.
File SDCardRoot = Environment.getExternalStorageDirectory();
//create a new file, specifying the path, and the filename
//which we want to save the file as.
File file = new File(SDCardRoot,"somefile.jpg");
//this will be used to write the downloaded data into the file we created
FileOutputStream fileOutput = new FileOutputStream(file);
//this will be used in reading the data from the internet
InputStream inputStream = urlConnection.getInputStream();
//this is the total size of the file
int totalSize = urlConnection.getContentLength();
//variable to store total downloaded bytes
int downloadedSize = 0;
//create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0; //used to store a temporary size of the buffer
//now, read through the input buffer and write the contents to the file
while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
//add the data in the buffer to the file in the file output stream (the file on the sd card
fileOutput.write(buffer, 0, bufferLength);
//add up the size so we know how much is downloaded
downloadedSize += bufferLength;
//this is where you would do something to report the prgress, like this maybe
//updateProgress(downloadedSize, totalSize);
}
//close the output stream when done
fileOutput.close();
//catch some possible errors...
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
}
现在您直接在SD卡中下载了图像。不要忘记在外部存储的清单中给予许可。