Android Picture Bitmap,drawable,res Resource Picture Conversion

First, Knowledge introduction

①res resource picture is a resource picture placed under the project res file

②bitmap Bitmap, the general file suffix is BMP, need encoder coding, such as rgb565,rgb8888. A pixel-wise display object with high execution efficiency, but with obvious drawbacks and low storage efficiency.

③drawable, a general-purpose graphical object that can load commonly used images, gif,png,jpg, also supports BMP, providing some advanced visual objects such as gradients, graphics, etc.

　　　　

second, the project case"Step"

① put the picture in the Res/drawable folder, the picture belongs to res resource picture

② defines image processing as a tool class that is easy to use or not.

③ Click on the button to get the picture and show it.

"Project Structure"

　　　　

"Imghelper"

1 ImportAndroid.content.Context;2 ImportAndroid.graphics.Bitmap;3 Importandroid.graphics.BitmapFactory;4 ImportAndroid.graphics.Canvas;5 ImportAndroid.graphics.PixelFormat;6 Importandroid.graphics.drawable.BitmapDrawable;7 Importandroid.graphics.drawable.Drawable;8 9  Public classImghelper {Ten  One      Public StaticBitmap getbitmapformresources (Context context,intresId) { A         returnBitmapfactory.decoderesource (Context.getresources (), resId); -     } -  the      Public StaticDrawable getdrawablefromresources (Context context,intresId) { -         returncontext.getresources (). getdrawable (resId); -     } -  +      Public Staticdrawable getdrawbleformbitmap (Context context,bitmap Bitmap) { -         return Newbitmapdrawable (Context.getresources (), bitmap); +     } A  at      Public StaticBitmap getbitmapformdrawable (Context context,drawable drawable) { -Bitmap Bitmap =Bitmap.createbitmap (Drawable.getintrinsicwidth (), -Drawable.getintrinsicheight (), drawable.getopacity ()! =Pixelformat.opaque -?Bitmap.Config.ARGB_8888:Bitmap.Config.RGB_565); -Canvas Canvas =NewCanvas (bitmap); -Drawable.setbounds (0,0, Drawable.getintrinsicwidth (), Drawable.getintrinsicheight ()); in         //sets the bounds of the painting, which represents the complete drawing - Drawable.draw (canvas); to         returnbitmap; +     } -}

"Tip" the canvas (canvas) is used to draw drawable when converted to bitmap. Sets the size of the drawing, drawing the bounds.

"Layout_main"

1 <Android.support.constraint.ConstraintLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"2 Xmlns:app= "Http://schemas.android.com/apk/res-auto"3 Xmlns:tools= "Http://schemas.android.com/tools"4 Android:layout_width= "Match_parent"5 Android:layout_height= "Match_parent"6 android:orientation= "vertical"7 Tools:context=". Mainactivity ">8 9     <ButtonTen         Android:id= "@+id/btnbitmapformres" One Android:text= "Bitmap form res" A Android:layout_width= "Match_parent" - Android:layout_height= "Wrap_content" /> -  the     <ImageView -         Android:id= "@+id/iv" - Android:layout_width= "Match_parent" - Android:layout_height= "Wrap_content" + Android:layout_marginend= "8DP" - Android:layout_marginleft= "8DP" + Android:layout_marginright= "8DP" A Android:layout_marginstart= "8DP" at Android:layout_margintop= "8DP" - app:layout_constraintend_toendof= "Parent" - App:layout_constraintstart_tostartof= "Parent" - App:layout_constrainttop_tobottomof= "@+id/btnbitmapformres" /> -  - </Android.support.constraint.ConstraintLayout>

"Hint" can see here ImageView not set picture

"Main_activity"

1 ImportAndroid.graphics.Bitmap;2 Importandroid.graphics.drawable.Drawable;3 Importandroid.support.v7.app.AppCompatActivity;4 ImportAndroid.os.Bundle;5 ImportAndroid.view.View;6 ImportAndroid.widget.Button;7 ImportAndroid.widget.ImageView;8 9 ImportCom.example.administrator.myapplication.utils.ImgHelper;Ten  One  Public classMainactivityextendsappcompatactivity { A  - Button btnbitmapformres; - ImageView IV; the  - @Override -     protected voidonCreate (Bundle savedinstancestate) { -         Super. OnCreate (savedinstancestate); + Setcontentview (r.layout.activity_main); -  +Btnbitmapformres =Findviewbyid (r.id.btnbitmapformres); AIV =Findviewbyid (R.ID.IV); atBtnbitmapformres.setonclicklistener (NewView.onclicklistener () { - @Override -              Public voidOnClick (view view) { -Bitmap bitmapformresources = imghelper.getbitmapformresources (mainactivity. This, R.DRAWABLE.IMG1); - //Iv.setimagebitmap (bitmapformresources); //Resources Picture Turn bitmap -  indrawable drawablefromresources = imghelper.getdrawablefromresources (mainactivity. This, R.DRAWABLE.IMG1); - //iv.setimagedrawable (drawablefromresources);//Resources Picture Turn drawable to  +Bitmap bitmapformdrawable = imghelper.getbitmapformdrawable (mainactivity. This, drawablefromresources); -Iv.setimagebitmap (bitmapformdrawable);////drawable turn Bitmap the  *drawable Drawbleformbitmap = Imghelper.getdrawbleformbitmap (mainactivity. This, bitmapformresources); $ //iv.setimagedrawable (DRAWBLEFORMBITMAP); //Bitmap Turn drawablePanax Notoginseng             } -         }); the     } +}

"Hint" in order to facilitate I wrote a button here, four ways, mutual cooperation, three forms of mutual transformation

the effects button will show the following effects when clicked

　　　　

Convert Android pictures bitmap,drawable,res resource pictures