/我得到了以下代码：
public class SketchActivity extends Activity implements OnClickListener, OnSeekBarChangeListener {
private MyView myView;
private Button clearBtn;
private ToggleButton embossBtn, blurBtn, eraseBtn, srcaBtn;
private RelativeLayout layout, layout2;
private TextView penSizeTxt;
SharedPreferences pref;
private Preview preview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
init();
preview = new Preview(this);
layout2 = (RelativeLayout) findViewById(R.id.paint_layout2);
layout = (RelativeLayout) findViewById(R.id.paint_layout);
layout.addView(preview);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
myView = new MyView(SketchActivity.this, layout.getWidth(), layout.getHeight());
layout2.addView(myView);
layout2.bringToFront();
}
}, 50);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFF000000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(5);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
private void init() {
clearBtn = (Button) findViewById(R.id.clearBtn);
embossBtn = (ToggleButton) findViewById(R.id.embossBtn);
blurBtn = (ToggleButton) findViewById(R.id.blurBtn);
eraseBtn = (ToggleButton) findViewById(R.id.eraseBtn);
srcaBtn = (ToggleButton) findViewById(R.id.srcatopBtn);
clearBtn.setOnClickListener(this);
embossBtn.setOnClickListener(this);
blurBtn.setOnClickListener(this);
eraseBtn.setOnClickListener(this);
srcaBtn.setOnClickListener(this);
}
private static Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
public void colorChanged(int color) {
mPaint.setColor(color);
}
private void setToggleOf() {
embossBtn.setChecked(false);
eraseBtn.setChecked(false);
blurBtn.setChecked(false);
srcaBtn.setChecked(false);
}
@Override
public void onClick(View v) {
if (v.getId() == embossBtn.getId()) {
if (mPaint.getMaskFilter() != mEmboss) {
setToggleOf();
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
mPaint.setMaskFilter(mEmboss);
embossBtn.setChecked(true);
} else {
mPaint.setMaskFilter(null);
embossBtn.setChecked(false);
}
} else if (v.getId() == blurBtn.getId()) {
if (mPaint.getMaskFilter() != mBlur) {
setToggleOf();
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
mPaint.setMaskFilter(mBlur);
blurBtn.setChecked(true);
} else {
mPaint.setMaskFilter(null);
blurBtn.setChecked(false);
}
} else if (v.getId() == eraseBtn.getId()) {
if (eraseBtn.isChecked()) {
setToggleOf();
eraseBtn.setChecked(true);
mPaint.setMaskFilter(null);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
} else {
mPaint.setMaskFilter(null);
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
}
} else if (v.getId() == srcaBtn.getId()) {
if (srcaBtn.isChecked()) {
setToggleOf();
mPaint.setMaskFilter(null);
srcaBtn.setChecked(true);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_ATOP));
mPaint.setAlpha(0x80);
} else {
mPaint.setMaskFilter(null);
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
}
}
else if (v.getId() == clearBtn.getId()) {
layout2.removeAllViews();
myView = new MyView(SketchActivity.this, layout.getWidth(), layout.getHeight());
layout2.addView(myView);
}
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
Bitmap bitmap;
int x = 0;
int y = 0;
int r = 0;
public MyView(Context c, int width, int height) {
super(c);
WindowManager wm = (WindowManager) c.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
int w = display.getWidth(); // deprecated
int h = display.getHeight();
// setFocusable(true);
// setBackgroundResource(R.drawable.download);
// setting paint
mPath = new Path();
mPaint = new Paint();
mPaint.setAlpha(0);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setAntiAlias(true);
mPaint.setMaskFilter(new BlurMaskFilter(10, BlurMaskFilter.Blur.NORMAL));
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
this.getContext().getResources();
Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.smoke);
Bitmap bm2 = getResizedBitmap(bm, h, w);
// converting image bitmap into mutable bitmap
bitmap = bm2.createBitmap(w, h, Config.ARGB_8888);
mCanvas = new Canvas();
mCanvas.setBitmap(bitmap); // drawXY will result on that Bitmap
mCanvas.drawBitmap(bm2, 0, 0, null);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
@Override
protected void onDraw(Canvas canvas) {
//mCanvas.drawCircle(x, y, r, mPaint);
// canvas.drawBitmap(bitmap, 0, 0, null);
canvas.drawBitmap(bitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
super.onDraw(canvas);
}
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);
// mPath.lineTo(x, y);
// mCanvas.drawPoint(x, y, mPaint);
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;
}
// invalidate();
}
private void touch_up() {
mPath.lineTo(mX, mY);
// 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;
}
public Bitmap getImage() {
return mBitmap;
}
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
// TODO Auto-generated method stub
penSizeTxt.setText(String.valueOf(progress + 2));
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
int width = bm.getWidth();
int height = bm.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// CREATE A MATRIX FOR THE MANIPULATION
Matrix matrix = new Matrix();
// RESIZE THE BIT MAP
matrix.postScale(scaleWidth, scaleHeight);
// RECREATE THE NEW BITMAP
Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
return resizedBitmap;
}
}
我希望它能够清除第二个布局并在触摸时显示相机的内容。因此，如果我用手指在屏幕上制作一条曲线，它会将这些像素设置为alpha，并从背面布局中看到相机。问题是，例如，如果我做一条曲线，应用程序也会删除该曲线的内容。因此，如果我用手指做一个圆圈，它也会擦除圆圈的内容，而不仅仅是边缘。
答案 0 :(得分：0)
onCreate我有：
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFF000000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(5);
然后在我的View上我有：
mPaint = new Paint();
mPaint.setAlpha(0);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setAntiAlias(true);
mPaint.setMaskFilter(new BlurMaskFilter(10, BlurMaskFilter.Blur.NORMAL));
覆盖mPaint，这就是它无法正常工作的原因。删除第二个：
mPaint = new Paint();
我让它发挥作用