Learn about Android by scaling the resource images (27)

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I use Setimagebitmap, Setimageresource, Bitmapfactory.decoderesource to set a picture when I load my pictures normally.

When the film is set by the above method, it will be done through the Java layer's createbitmap, which will consume a lot of memory and easily cause

OOM (out of Memory), it is recommended to use the Bitmapfactory.options class to set a resource graph.

See the following code:

public class Mainactivity extends Activity {private ImageView imageview1;private ImageView imageView2; Bitmap mbitmap; @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (R.layout.image); Initview ();} private void Initview () {imageview1= (ImageView) Findviewbyid (r.id.imageview1); imageview2= (ImageView) Findviewbyid ( R.ID.IMAGEVIEW2);//Read the resource Picture Mbitmap=readbitmap ();//Zoom the resource Picture Imageview2.setimagebitmap (Zoombitmap (Mbitmap, Mbitmap.getwidth ()/4, Mbitmap.getheight ()/4));} /** * Read Resource picture * @return */private Bitmap readbitmap () {bitmapfactory.options opt=new bitmapfactory.options ();/* * Set to allow decoder to best Mode decoding */opt.inpreferredconfig=bitmap.config.rgb_565;//The following two fields need to be combined using opt.inpurgeable=true;opt.ininputshareable=true ;/* * Get resource Picture */inputstream is=this.getresources (). Openrawresource (R.drawable.mei); return Bitmapfactory.decodestream (IS, null, opt);} /** * Zoom Picture * @param bitmap * @param w * @param h * @return */public bitmap zoombitmap (bitmap bitmap, int w, int h) {iNT width = bitmap.getwidth (); int height = bitmap.getheight (); Matrix matrix = new Matrix (), Float scalewidht = ((float) w/width), Float ScaleHeight = ((float) h/height);/* * via Matrix The Postscale method of the class is scaled */matrix.postscale (SCALEWIDHT, ScaleHeight); Bitmap newbmp = Bitmap.createbitmap (Bitmap, 0, 0, width, height, matrix, true); return newbmp;}}

Image.xml:

<?xml version= "1.0" encoding= "Utf-8"? ><relativelayout xmlns:android= "http://schemas.android.com/apk/res/ Android "    android:layout_width=" match_parent "    android:layout_height=" match_parent "    android:o rientation= "vertical" >    <imageview        android:id= "@+id/imageview1" android:layout_width= "Match_        Parent "        android:layout_height=" wrap_content "        android:src=" @drawable/mei "/>    <imageview        Android:id= "@+id/imageview2"        android:layout_width= "wrap_content"        android:layout_below= "@+id/ ImageView1 "        android:layout_height=" wrap_content "        android:layout_margintop=" 10DP "        android:src=" @ Drawable/mei "/></relativelayout>

Reprint Please specify source:http://blog.csdn.net/hai_qing_xu_kong/article/details/44281087 Emotional Control _

Learn about Android by scaling the resource images (27)