| ： Import Java.io.File;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.io.InputStream;
Import Java.io.OutputStream;
Import Java.net.URL;
Import java.net.URLConnection; Import Android.content.Context;
Import Android.graphics.Bitmap;
Import Android.graphics.BitmapFactory;
Import android.graphics.drawable.Drawable;
Import Android.net.Uri;
Import Android.os.AsyncTask;
Import Android.util.AttributeSet;
Import Android.widget.ImageView; /**
* Asynchronous Picture control
* Use: New Asyncimageview (). Asyncloadbitmapfromurl ("Http://xxxx", "cache path") {
*
* @author gaoomei@gmail.com
* @site http://obatu.sinaapp.com
* @version 1.0
* @2011-12-3
*/
public class Asyncimageview extends ImageView { /**
* Asynchronous Task Loader
*/
Private Asyncloadimage masyncload; /**
* Download back picture cache live time, unit: seconds (s), default 30 minutes
*/
Private long mcachelivetime = 1800; Public Asyncimageview {
Super (context);
} Public Asyncimageview (context context, AttributeSet Attrs) {
Super (context, attrs);
} Public Asyncimageview (context context, AttributeSet attrs, int defstyle) {
Super (context, attrs, Defstyle);
} /**
*
*/
@Override
public void setimagedrawable (drawable drawable) {
if (masyncload!= null) {
Masyncload.cancel (TRUE);
Masyncload = null;
}
Super.setimagedrawable (drawable);
} /**
* Rewrite the following methods to set the picture resource, which is to cancel the network load
*/
@Override
public void Setimageresource (int resid) {
Cancelload ();
Super.setimageresource (RESID);
} @Override
public void Setimageuri (Uri uri) {
Cancelload ();
Super.setimageuri (URI);
} @Override
public void Setimagebitmap (Bitmap Bitmap) {
Cancelload ();
Super.setimagebitmap (bitmap);
} /**
* Cancel an asynchronous task in progress
*/
public void Cancelload () {
if (masyncload!= null) {
Masyncload.cancel (TRUE);
Masyncload = null;
}
} /**
* Set Picture Survival time
*
* @param second
* Survival time, unit "seconds", if equal to 0 or null, do not cache
*/
public void Setcachelivetime (long second) {
if (second = = 0) {
This.mcachelivetime = 0;
else if (second >= 0) {
This.mcachelivetime = second * 1000;
}
} /**
* Asynchronous loading from the network
*
* @param URL
* @param savefilename
*/
public void Asyncloadbitmapfromurl (string url, string savefilename) {
if (masyncload!= null) {
Masyncload.cancel (TRUE);
}
Asynctask is not reusable, so each time a new instance
Masyncload = new Asyncloadimage ();
Masyncload.execute (URL, savefilename);
} /**
* Asynchronous Loader
*/
Private class Asyncloadimage extends Asynctask {
/**
* Whether to cancel
*/
Private Boolean iscancel = false; @Override
Protected Bitmap doinbackground (String ... params) {
if (iscancel) {
return null;
}
String URL = params[0];
String fileName = params[1];
try {
Return Getbitmap (URL, fileName);
catch (IOException e) {
E.printstacktrace ();
}
return null;
} @Override
protected void oncancelled () {
System.out.println ("Async load Imgae Cancel");
Iscancel = true;
} @Override
protected void OnPostExecute (Bitmap result) {
if (!iscancel && result!= null) {
AsyncImageView.this.setImageBitmap (result);
}
}
} /**
* Download pictures
*
* @param urlstring
* URL Download Address
* @param fileName
* Cache file path
* @throws IOException
*/
Private Bitmap Getbitmap (String urlstring, String fileName)
Throws IOException {
if (FileName = = NULL | | Filename.trim (). IsEmpty ()) {
InputStream input = Getbitmapinputstreamfromurl (urlstring);
return Bitmapfactory.decodestream (input);
} file file = new file (fileName);
if (!file.isfile ()
| | (Mcachelivetime > 0 && (System.currenttimemillis ()
- File.lastmodified () > Mcachelivetime)) {
inputstream input = Getbitmapinputstreamfromurl ( URLString);
file = saveimage (input, fileName);
//If the file structure creation fails, decode the picture directly from the input stream
if (file = = NULL | | |!file.exists () | |! File.canwrite ()
| |!file.canread ()) {
return Bitmapfactory.decodestream (input);
}
}
return Bitmapfactory.decodefile (File.getabsolutepath ());
} /**
* Download pictures, enter InputStream
*
* @param urlstring
* @return
* @throws IOException
*/
Private InputStream Getbitmapinputstreamfromurl (String urlstring)
Throws IOException {
URL url = new URL (urlstring);
URLConnection connection = Url.openconnection ();
Connection.setconnecttimeout (25000);
Connection.setreadtimeout (90000);
return Connection.getinputstream ();
} /**
* Save pictures from input stream to file system
*
* @param fileName
* @param input
* @return
*/
Private File saveimage (InputStream input, String fileName) {
if (Filename.trim (). IsEmpty () | | input = = NULL) {
return null;
}
File File = new file (fileName);
OutputStream output = null;
try {
File.getparentfile (). Mkdirs ();
if (file.exists () && file.isfile ()) {
File.delete ();
}
if (!file.createnewfile ()) {
return null;
}
Output = new FileOutputStream (file);
byte[] buffer = new BYTE[4 * 1024];
do {
Looping read
int numread = input.read (buffer);
if (Numread = = 1) {
Break
}
Output.write (buffer, 0, numread);
} while (true);
Output.flush ();
catch (Exception e) {
E.printstacktrace ();
finally {
try {
Output.close ();
catch (IOException e) {
E.printstacktrace ();
catch (Exception E2) {
E2.printstacktrace ();
}
}
return file;
}
} |
