问题
I am using the following class to download a specific map and i'd like to draw it to a canvas with other bitmaps but when I do it only the map doesn't show up. I know the map is downloading, do I have to make it mutable, i'm not completely sure what's going on here.
class TheTask extends AsyncTask<Void,Void,Void>
{
File mediaFile = new File(MenuScreen.mediaStorageDir.getPath() + File.separator +
"IMG_"+ MenuScreen.timeStamp + ".png");
File mediaFile1 = new File(MenuScreen.mediaStorageDir.getPath() + File.separator +
"IMG_"+ MenuScreen.timeStamp + "1" + ".png");
File mediaFile2 = new File(MenuScreen.mediaStorageDir.getPath() + File.separator +
"IMG_"+ MenuScreen.timeStamp + "2" + ".png");
Bitmap bitmap;
protected void onPreExecute()
{ super.onPreExecute();
//display progressdialog.
}
protected Void doInBackground(Void ...params)
{
bitmap = getGoogleMapThumbnail(MainActivity.latlng.latitude,MainActivity.latlng.longitude);
FileOutputStream outStream;
try {
outStream = new FileOutputStream(mediaFile2);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
outStream.flush();
outStream.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//mapView.setDrawingCacheEnabled(enabled);
//mediaFile = new File(MenuScreen.mediaStorageDir.getPath() + File.separator +
// "IMG_"+ MenuScreen.timeStamp + ".jpg");
return null;
}
protected void onPostExecute(Void result)
{
super.onPostExecute(result);
Bitmap finished;
String path = mediaFile1.getAbsolutePath();
String path1 = mediaFile2.getAbsolutePath();
Bitmap map = BitmapFactory.decodeFile(path1);
Bitmap photo = BitmapFactory.decodeFile(path);
Paint into = new Paint();
into.setFilterBitmap(true);
into.setColor(Color.BLACK);
into.setTextSize(25);
into.setUnderlineText(true);
into.setTypeface(Typeface.DEFAULT_BOLD);
Bitmap datetime = Bitmap.createBitmap(200,200,Bitmap.Config.ARGB_8888);
Canvas can = new Canvas(datetime);
can.drawColor(Color.WHITE);
can.drawText(MainActivity.curDate, 0, 35, into);
can.drawText(MainActivity.curTime, 0, 70, into);
if(photo.getWidth() > photo.getHeight()){
finished = Bitmap.createBitmap(480,720,Bitmap.Config.ARGB_8888);
Canvas ca = new Canvas(finished);
ca.drawColor(Color.WHITE);
ca.drawBitmap(map,0, 0, null);
ca.drawBitmap(datetime, 0, 0, null);
//ca.drawBitmap(bm, new Rect(0,0, bm.getWidth(), bm.getHeight()),new Rect(280,0,480,200) , null);
ca.drawBitmap(photo, 0, 400, null);
}else{
finished = Bitmap.createBitmap(720,480,Bitmap.Config.ARGB_8888);
Canvas ca = new Canvas(finished);
ca.drawColor(Color.WHITE);
ca.drawBitmap(map, 320, 0, null);
ca.drawBitmap(datetime, 320, 0, null);
//ca.drawBitmap(bm, new Rect(0,0, bm.getWidth(), bm.getHeight()),new Rect(320,280,520,480) , null);
ca.drawBitmap(photo, 0, 0, null);
}
mediaFile1.delete();
mediaFile2.delete();
FileOutputStream outStream;
try {
outStream = new FileOutputStream(mediaFile);
finished.compress(Bitmap.CompressFormat.PNG, 100, outStream);
outStream.flush();
outStream.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//sendBroadcast(new Intent(
// Intent.ACTION_MEDIA_MOUNTED,
// Uri.parse("file://" + Environment.getExternalStorageDirectory())));
//dismiss progressdialog.
//update ui
}
public static Bitmap getGoogleMapThumbnail(double lati, double longi){
String URL = "http://maps.google.com/maps/api/staticmap?center=" +lati + "," + longi + "&zoom=15&size=200x200&sensor=false";
Bitmap bmp = null;
bmp = getBitmapFromURL(URL);
/*HttpClient httpclient = new DefaultHttpClient();
HttpGet request = new HttpGet(URL);
InputStream in = null;
try {
in = httpclient.execute(request).getEntity().getContent();
bmp = BitmapFactory.decodeStream(in);
in.close();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
return bmp;
}
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;
}
}
回答1:
As i mentioned in comments, You could actually reuse the bitmap.
You could also draw on canvas directly for date and time since the datetime bitmap will consume 160000 bytes i.e 156kb.
I have not tested the code. This is just a suggestion.
class TheTask extends AsyncTask<Void, Void, Bitmap> {
File mediaFile = new File(MenuScreen.mediaStorageDir.getPath() + File.separator + "IMG_" + MenuScreen.timeStamp + ".png");
File mediaFile1 = new File(MenuScreen.mediaStorageDir.getPath() + File.separator + "IMG_" + MenuScreen.timeStamp + "1" + ".png");
//File mediaFile2 = new File(MenuScreen.mediaStorageDir.getPath() + File.separator + "IMG_" + MenuScreen.timeStamp + "2" + ".png");
Bitmap mapBitmap;
protected void onPreExecute() {
super.onPreExecute();
// display progressdialog.
}
protected Bitmap doInBackground(Void... params) {
mapBitmap = getGoogleMapThumbnail(MainActivity.latlng.latitude, MainActivity.latlng.longitude);
// You could reuse this bitmap. Rather than saving and loading again
return mapBitmap;
}
protected void onPostExecute(Bitmap map) {
super.onPostExecute(map);
Bitmap finished;
String path = mediaFile1.getAbsolutePath();
Bitmap photo = BitmapFactory.decodeFile(path);
Paint into = new Paint();
Paint background = new Paint();
background.setColor(Color.WHITE);
background.setStyle(Style.FILL);
into.setFilterBitmap(true);
into.setColor(Color.BLACK);
into.setTextSize(25);
into.setUnderlineText(true);
into.setTypeface(Typeface.DEFAULT_BOLD);
// Bitmap datetime = Bitmap.createBitmap(200, 200,
// Bitmap.Config.ARGB_8888);
//
// Canvas can = new Canvas(datetime);
// can.drawColor(Color.WHITE);
// can.drawText(MainActivity.curDate, 0, 35, into);
// can.drawText(MainActivity.curTime, 0, 70, into);
Rect rect = new Rect();
if (photo.getWidth() > photo.getHeight()) {
finished = Bitmap.createBitmap(480, 720, Bitmap.Config.ARGB_8888);
Canvas ca = new Canvas(finished);
ca.drawColor(Color.WHITE);
ca.drawBitmap(map, 0, 0, null);
rect.set(0, 0, 200, 200);
ca.drawRect(rect, background);
ca.drawText(MainActivity.curDate, 0, 35, into);
ca.drawText(MainActivity.curTime, 0, 70, into);
ca.drawBitmap(photo, 0, 400, null);
}
else {
finished = Bitmap.createBitmap(720, 480, Bitmap.Config.ARGB_8888);
Canvas ca = new Canvas(finished);
ca.drawColor(Color.WHITE);
ca.drawBitmap(map, 320, 0, null);
ca.save();
ca.translate(320, 0);
rect.set(0, 0, 200, 200);
ca.drawRect(rect, background);
ca.drawText(MainActivity.curDate, 0, 35, into);
ca.drawText(MainActivity.curTime, 0, 70, into);
ca.restore();
ca.drawBitmap(photo, 0, 0, null);
}
mediaFile1.delete();
FileOutputStream outStream;
try {
outStream = new FileOutputStream(mediaFile);
finished.compress(Bitmap.CompressFormat.PNG, 100, outStream);
outStream.flush();
outStream.close();
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
}
public static Bitmap getGoogleMapThumbnail(double lati, double longi) {
String URL = "http://maps.google.com/maps/api/staticmap?center=" + lati + "," + longi + "&zoom=15&size=200x200&sensor=false";
Bitmap bmp = null;
bmp = getBitmapFromURL(URL);
return bmp;
}
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;
}
}
}
来源：https://stackoverflow.com/questions/16119050/can-you-draw-a-google-static-map-to-a-canvas-after-you-download-it