This example describes the bitmap usage in Android. Share to everyone for your reference. Specifically as follows:
The image formats you can support in the Android SDK are as follows: PNG, JPG, GIF, and BMP.
Creation of 1.Bitmap
With the help of Bitmapfactory.
1 The picture in the resource
Using Bitmapfactory to get bitmaps
Copy Code code as follows:
Bitmap bmp = Bitmapfactory.decoderesource (This.getresources (), r.drawable.testimg);
Or is:
Resources res=getresources ();
Use Bitmapdrawable to get the bitmap
/////Use Bitmapdrawable (InputStream is) to construct a bitmapdrawable;
Use the Getbitmap () of the Bitmapdrawable class to obtain the
bitmap;//Read the InputStream and get the bitmaps
InputStream Is=res.openrawresource ( R.DRAWABLE.TESTIMG);
Bitmapdrawable bmpdraw=new bitmapdrawable (IS);
Bitmap Bmp=bmpdraw.getbitmap ();
2 Image in SD card
Copy Code code as follows:
Bitmap bmp = Bitmapfactory.decodefile ("/sdcard/testbitmap/testimg.png")
2. Keep the Bitmap in the SDcard
File Fimage = new file ("/sdcard/testbitmap/testimg.png");
Fimage.createnewfile ();
FileOutputStream IStream = new FileOutputStream (fimage);
Bmp.compress (Compressformat.png, iStream);
Istream.close ();
Fimage.close ();
IStream =null;
Fimage =null;
Write to the output stream and save it to the file.
3. Using pictures from the network
The link address of the picture
String imgurlstr = "yun_qi_img/990e6271796a7a6c170c.jpg";
URL imgurl = new URL (imgurlstr);
URLConnection conn = Imgurl.openconnection ();
Conn.connect ();
InputStream is = Conn.getinputstream ();
Bufferedinputstream bis = new Bufferedinputstream (is);
Download picture
Bitmap bmp = Bitmapfactory.decodestream (bis);
Close Stream
bis.close ();
Is.close ();
Imgurl =null;
4. Display Picture
1) Convert to Bitmapdrawable object display bitmap
Convert to Bitmapdrawable object
bitmapdrawable bmpdraw=new bitmapdrawable (BMP);
Display bitmap
ImageView iv2 = (imageview) Findviewbyid (r.id.imageview02);
Iv2.setimagedrawable (Bmpdraw);
2 using the Canvas class to display the bitmap
Copy Code code as follows:
Canvas.drawbitmap (BMP, 0, 0, NULL);
5. Zoom Bitmap
1 will be a bitmap in accordance with the requirements of the redraw, the picture after the bitmap is what we need, and the display of the bitmap almost the same:
Copy Code code as follows:
Drawbitmap (Bitmap Bitmap, Rect src, Rect DST, Paint Paint)
2 on the basis of the original bitmap, scale in-situ diagram, create a new bitmap:
Copy Code code as follows:
CreateBitmap (Bitmap source, int x, int y, int width, int height, Matrix m, Boolean filter)
3) with the help of Canvas's scale (float SX, float sy), be aware that the entire canvas is scaled at this time.
4) Using matrix:
Matrix matrix=new Matrix ();
Matrix.postscale (0.2f, 0.2f);
Bitmap Dstbmp=bitmap.createbitmap (Bmp,0,0,bmp.getwidth (), Bmp.getheight (), matrix,true);
Canvas.drawbitmap (dstbmp, ten, NULL);
6. Rotate Bitmap
Using the matrix or canvas to achieve.
Matrix matrix=new Matrix ();
Matrix.postrotate ();
Bitmap Dstbmp=bitmap.createbitmap (Bmp,0,0,bmp.getwidth (), Bmp.getheight (), matrix,true);
Canvas.drawbitmap (dstbmp, ten, NULL);
I hope this article will help you with your Android program.