In Android, the most commonly used classes for drawing images are the Paint class (brush), Canvas class (canvas), Bitmap class (bitmap), BitmapFactory (tool class)
With a brush and a canvas, you can paint!
Brush
Creates a brush, specifying that the brush's color is red with a light gray shading:
Paint paint=new Paint(); paint.setColor(Color.RED); paint.setShadowLayer(2,3,3,Color.rgb(180,180,180));
Commonly used properties
canvas
The Canvas class represents a canvas, and various graphics (rectangles, circles, lines, etc.) can be drawn through the methods provided by this class. Normally, to draw in Android, you need to create a view that inherits from the View class, override its onDraw(Canvas canvas) method in this class, and then add the view to the Activity that displays and spit.
Create the canvas:
public class DrawView extends View { /** * Function: Constructor */ public DrawView(Context context, AttributeSet attrs) { super(context, attrs); } /* * Function: Override the onDraw() method */ @Override protected void onDraw(Canvas canvas) { Paint paint=new Paint(); //Define a brush with default settings paint.setColor(Color.RED); //Set the color to red paint.setShadowLayer(2, 3, 3, Color.rgb(180, 180, 180)); //Set the shadow canvas.drawRect(40, 40, 200, 100, paint); //Draw a rectangle super.onDraw(canvas); } }
Example:
Draw a circle: Canvas.drawCricle(float cx,float cy,float radius,Paint paint); draw a rectangle Canvas.drawRect(float left,float top,float right,float bottom,Paint paint); draw an ellipse Canvas.drawOval(RectF oval,Paint paint);
draw text
Canvas.drawText(String text,float x,float y,Paint paint); text: the text to draw x,y: horizontal and vertical coordinates paint: brush
Multimedia technology
uses MediaPlay to play audio
MediaPlay player=MediaPlayer.create(this,R.raw.d); player.start(); player.pause (); player.stop();