我需要为我在学校的期末项目创建一个“刮刮卡”应用程序,但找不到实现刮刮事件的方法(如何创建背景图像并在其上放置灰色矩形,所以我什么时候会划破那些矩形我会看到它们下面的图片)
实现必须在 Android 中,因为我还不知道如何在 Objective-C 中开发。
我看到了 Objective-C Implementation 的引用资料,但它不好,因为我不明白。
我的代码是:
public class FingerPaint extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
MyView myView = new MyView(this);
myView.requestFocus();
myView.PaintObjectInit();
// setContentView(myView);
LinearLayout upper = (LinearLayout) findViewById(R.id.LinearLayout01);
upper.addView(myView);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
// MyImageView myImageView = new MyImageView(this);
// setContentView(myImageView);
}
}
public class MyView extends View {
private Paint mPaint;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
public MyView(Context context) {
super(context);
this.mPaint = new Paint();
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
protected void PaintObjectInit() {
mPaint.setAntiAlias(true);
mPaint.setDither(true);
//mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
//mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
try
{
//Bitmap bm1 = BitmapFactory.decodeResource(this.getResources(),R.drawable.scratch).copy(Bitmap.Config.ARGB_8888, true);;
//Bitmap bm2 = BitmapFactory.decodeResource(this.getResources(),R.drawable.main).copy(Bitmap.Config.ARGB_8888, true);;
//mBitmap = toTransparency(bm1, 0xFFAAAAAA, true, bm2);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(0xFFAAAAAA);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
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);
// 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;
}
}
请就此提供帮助。
最佳答案
我最近遇到这个问题,然后我为此创建了一个库,以便每个人都可以快速实现 scratch view,希望这可以帮助那些仍在寻找答案的人 https://github.com/winsontan520/Android-WScratchView
关于android - 如何在 Android 中创建刮刮卡?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8892632/