对于新手,此代码将帮助您创建涂鸦图像并将其导出为 Png 图像这里是 完整的代码,这个活动类也包含一个视图类。
public class MainActivity extends Activity {
private Bitmap DrawBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint DrawBitmapPaint;
RelativeLayout Rl;
CustomView View;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
View = new CustomView(this);
Rl = (RelativeLayout) findViewById(R.id.Rel);
Rl.addView(View);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(getResources()
.getColor(android.R.color.holo_green_dark));
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(20);
}
private Paint mPaint;
public class CustomView extends View {
@SuppressWarnings("deprecation")
public CustomView(Context c) {
super(c);
Display Disp = getWindowManager().getDefaultDisplay();
DrawBitmap = Bitmap.createBitmap(Disp.getWidth(), Disp.getHeight(),
Bitmap.Config.ARGB_4444);
mCanvas = new Canvas(DrawBitmap);
mPath = new Path();
DrawBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
@Override
protected void onDraw(Canvas canvas) {
setDrawingCacheEnabled(true);
canvas.drawBitmap(DrawBitmap, 0, 0, DrawBitmapPaint);
canvas.drawPath(mPath, mPaint);
canvas.drawRect(mY, 0, mY, 0, DrawBitmapPaint);
}
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;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, mPaint);
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;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
mPaint.setXfermode(null);
switch (item.getItemId()) {
case R.id.erase:
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
break;
case R.id.DELETE:
View = new CustomView(this);
break;
case R.id.draw:
mPaint.setXfermode(null);
break;
case R.id.Save:
String pattern = "mm ss";
SimpleDateFormat formatter = new SimpleDateFormat(pattern);
String time = formatter.format(new Date());
String path = ("/d-codepages" + time + ".png");
File file = new File(Environment.getExternalStorageDirectory()
+ path);
try {
DrawBitmap.compress(Bitmap.CompressFormat.PNG, 100,
new FileOutputStream(file));
Toast.makeText(this, "File Saved ::" + path, Toast.LENGTH_SHORT)
.show();
} catch (Exception e) {
Toast.makeText(this, "ERROR" + e.toString(), Toast.LENGTH_SHORT)
.show();
}
}
return super.onOptionsItemSelected(item);
}
}