求Android中canvas.drawPicture(p);的使用方法?求一个简单的实例?
这个可能稍微复杂一点，但是非常实用：
public class MainActivity extends Activity {
DrawingView dv ;
private Paint mPaint;
private DrawingManager mDrawingManager=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dv = new DrawingView(this);
setContentView(dv);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.GREEN);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
}
public class DrawingView extends View {
public int width;
public int height;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
Context context;
private Paint circlePaint;
private Path circlePath;
public DrawingView(Context c) {
super(c);
context=c;
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
circlePaint = new Paint();
circlePath = new Path();
circlePaint.setAntiAlias(true);
circlePaint.setColor(Color.BLUE);
circlePaint.setStyle(Paint.Style.STROKE);
circlePaint.setStrokeJoin(Paint.Join.MITER);
circlePaint.setStrokeWidth(4f);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap( mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath( mPath, mPaint);
canvas.drawPath( circlePath, circlePaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
circlePath.reset();
circlePath.addCircle(mX, mY, 30, Path.Direction.CW);
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
circlePath.reset();
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
}
}
你的手指到哪里，Canvas就画到哪里。图：
写得非常好，不过drawPicture方法没有用啊
哈哈，我看错了。这个应该可以“
private static class SampleView extends View {
private Picture mPicture;
private Drawable mDrawable;
public SampleView(Context context) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
mPicture = new Picture();
mPicture.endRecording();
mDrawable = new PictureDrawable(mPicture);
}
@Override protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
canvas.drawPicture(mPicture, new RectF(0, 100, getWidth(), 200));
mDrawable.setBounds(0, 200, getWidth(), 300);
mDrawable.draw(canvas);
ByteArrayOutputStream os = new ByteArrayOutputStream();
mPicture.writeToStream(os);
InputStream is = new ByteArrayInputStream(os.toByteArray());
canvas.translate(0, 300);
canvas.drawPicture(Picture.createFromStream(is));
}
网上看的
微测检测
2023-10-30 广告
