发布于 2016-05-02 10:57:29 | 167 次阅读 | 评论: 0 | 来源: 网友投递
Android移动端操作系统
Android是一种基于Linux的自由及开放源代码的操作系统,主要使用于移动设备,如智能手机和平板电脑,由Google公司和开放手机联盟领导及开发。尚未有统一中文名称,中国大陆地区较多人使用“安卓”或“安致”。
主要思想:
将一个view设计成多层:背景层,含中奖信息等;
遮盖层,用于刮奖,使用关联一个Bitmap的Canvas
在该Bitmap上,使用它的canvas.drawPath的api来处理 手势滑动(类似刮奖的动作)
使用paint.setXfermode 来进行消除手势滑动区域
public class GuaView extends View {
private Bitmap mBitmap; //遮盖的图层
private Canvas mCanvas; //绘制遮盖图层
private Paint mOuterPaint;
private Path mPath;
private float mLastX;
private float mLastY;
private Bitmap mCoverBitmap; //遮盖图
private int mWidth, mHeight;
private Paint mInnerPaint;
private String mInfo;
public GuaView(Context context) {
this(context, null);
}
public GuaView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
mPath = new Path();
mOuterPaint = new Paint();
mInnerPaint = new Paint();
mCoverBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.fg_guaguaka);
mInfo = "¥ 5 0 0";
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mWidth = mCoverBitmap.getWidth();
mHeight = mCoverBitmap.getHeight();
setMeasuredDimension(mWidth, mHeight);
mBitmap = Bitmap.createBitmap(mWidth, mHeight, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mCanvas.drawBitmap(mCoverBitmap, 0, 0, null);
setOuterPaint();
setInnerPaint();
}
private void setInnerPaint() {
mInnerPaint.setColor(Color.RED);
mInnerPaint.setStyle(Paint.Style.STROKE);
mInnerPaint.setStrokeCap(Paint.Cap.ROUND);
mInnerPaint.setStrokeJoin(Paint.Join.ROUND);
mInnerPaint.setAntiAlias(true);
mInnerPaint.setDither(true); //防抖
mInnerPaint.setStrokeWidth(5);
mInnerPaint.setTextSize(100);
mInnerPaint.setTextAlign(Paint.Align.CENTER);
}
private void setOuterPaint() {
mOuterPaint.setColor(Color.GREEN);
mOuterPaint.setStyle(Paint.Style.STROKE);
mOuterPaint.setStrokeCap(Paint.Cap.ROUND);
mOuterPaint.setStrokeJoin(Paint.Join.ROUND);
mOuterPaint.setAntiAlias(true);
mOuterPaint.setDither(true); //防抖
mOuterPaint.setStrokeWidth(20);
}
@Override //Path
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mLastX = x;
mLastY = y;
mPath.moveTo(x, y);
break;
case MotionEvent.ACTION_MOVE:
float deltaX = Math.abs(x - mLastX);
float deltaY = Math.abs(y - mLastY);
if (deltaX > 5 || deltaY > 5) {
mPath.lineTo(x, y);
}
mLastX = x;
mLastY = y;
break;
case MotionEvent.ACTION_UP:
break;
}
invalidate();//调用onDraw
return true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.parseColor("#bbbbbb")); //背景底色 灰色
canvas.drawText(mInfo, mWidth / 2, mHeight / 4 * 3, mInnerPaint); //绘制文本
canvas.drawBitmap(mBitmap, 0, 0, null); //绘制mBitmap 这是一个可变的bitmap,通过mCanvas绘制,首先绘制了mCoverBitmap
drawPath();
}
private void drawPath() {
//使用该mode:dst和src相交后, 只保留dst,且除去相交的部份
mOuterPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
mCanvas.drawPath(mPath, mOuterPaint);
}
}
Paint.Join 连续画笔衔接时:
Paint.Cap 指定对于 线和路径(lines and paths) 的开始和结束点的处理方式: