1 效果
2 源码
/*** 自动上下扫描*/public class AutoScannerView extends View {private static final String TAG = AutoScannerView.class.getSimpleName();private Paint maskPaint;private Paint linePaint;private Paint traAnglePaint;private Paint textPaint;private final int maskColor = Color.parseColor("#60000000");//蒙在摄像头上面区域的半透明颜色private final int triAngleColor = Color.parseColor("#76EE00"); //边角的颜色private final int lineColor = Color.parseColor("#FF0000"); //中间线的颜色private final int textColor = Color.parseColor("#CCCCCC"); //文字的颜色private final int triAngleLength = dp2px(20); //每个角的点距离private final int triAngleWidth = dp2px(4); //每个角的点宽度private final int textMarinTop = dp2px(30); //文字距离识别框的距离private int lineOffsetCount = 0;public AutoScannerView(Context context, AttributeSet attrs) {super(context, attrs);maskPaint = new Paint(Paint.ANTI_ALIAS_FLAG);maskPaint.setColor(maskColor);traAnglePaint = new Paint(Paint.ANTI_ALIAS_FLAG);traAnglePaint.setColor(triAngleColor);traAnglePaint.setStrokeWidth(triAngleWidth);traAnglePaint.setStyle(Paint.Style.STROKE);linePaint = new Paint(Paint.ANTI_ALIAS_FLAG);linePaint.setColor(lineColor);textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);textPaint.setColor(textColor);textPaint.setTextSize(dp2px(14));}//默认view的宽度private int mDefaultWidth = dp2px(100);private int mDefaultHeight = mDefaultWidth;private int mDefaultPadding = dp2px(10);//绘制进度条的实际宽度private int mMeasureHeight;private int mMeasureWidth;@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);//测量计算宽度int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);if (widthSpecMode == MeasureSpec.EXACTLY) {//当specMode = EXACTLY时，精确值模式，即当我们在布局文件中为View指定了具体的大小mMeasureWidth = widthSpecSize;} else {//指定默认大小mMeasureWidth = mDefaultWidth;if (widthSpecMode == MeasureSpec.AT_MOST) {mMeasureWidth = Math.min(mMeasureWidth, widthSpecSize);}}//测量计算View的高int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);if (heightSpecMode == MeasureSpec.EXACTLY) {//当specMode = EXACTLY时，精确值模式，即当我们在布局文件中为View指定了具体的大小mMeasureHeight = heightSpecSize;} else {//指定默认大小mMeasureHeight = mDefaultHeight;if (heightSpecMode == MeasureSpec.AT_MOST) {mMeasureHeight = Math.min(mMeasureHeight, heightSpecSize);}}mMeasureHeight = mMeasureHeight - getPaddingBottom() - getPaddingTop();mMeasureWidth = mMeasureWidth - getPaddingLeft() - getPaddingBottom();//重新测量setMeasuredDimension(mMeasureWidth, mMeasureHeight);/*** 竖屏状态下* 将view 的宽度平均分为6份，扫描区域距左右各1份，那么扫描区域的宽度占4份* 将view 的调试平均分为4份，距离顶部1份，为保持与宽相等，bottom =mMeasureHeight/4+ width;*/int left =mMeasureWidth/6;int width = mMeasureWidth/6*4;int top = mMeasureHeight/4;int bottom =mMeasureHeight/4+ width;if (mMeasureHeight<mMeasureWidth){top = mMeasureHeight/8;bottom =mMeasureHeight/8*6;left =(mMeasureWidth-(bottom-top))/2;width = (bottom-top);}frame = new Rect( left,top, left+width, bottom);}Rect frame;@Overrideprotected void onDraw(Canvas canvas) {if (frame == null) {return;}int width = canvas.getWidth();int height = canvas.getHeight();// 除了中间的识别区域，其他区域都将蒙上一层半透明的图层canvas.drawRect(0, 0, width, frame.top, maskPaint);canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, maskPaint);canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, maskPaint);canvas.drawRect(0, frame.bottom + 1, width, height, maskPaint);String text = "将二维码放入框内，即可自动扫描";canvas.drawText(text, (width - textPaint.measureText(text)) / 2, frame.bottom + textMarinTop, textPaint);// 四个角落的三角Path leftTopPath = new Path();leftTopPath.moveTo(frame.left + triAngleLength, frame.top + triAngleWidth / 2);leftTopPath.lineTo(frame.left + triAngleWidth / 2, frame.top + triAngleWidth / 2);leftTopPath.lineTo(frame.left + triAngleWidth / 2, frame.top + triAngleLength);canvas.drawPath(leftTopPath, traAnglePaint);Path rightTopPath = new Path();rightTopPath.moveTo(frame.right - triAngleLength, frame.top + triAngleWidth / 2);rightTopPath.lineTo(frame.right - triAngleWidth / 2, frame.top + triAngleWidth / 2);rightTopPath.lineTo(frame.right - triAngleWidth / 2, frame.top + triAngleLength);canvas.drawPath(rightTopPath, traAnglePaint);Path leftBottomPath = new Path();leftBottomPath.moveTo(frame.left + triAngleWidth / 2, frame.bottom - triAngleLength);leftBottomPath.lineTo(frame.left + triAngleWidth / 2, frame.bottom - triAngleWidth / 2);leftBottomPath.lineTo(frame.left + triAngleLength, frame.bottom - triAngleWidth / 2);canvas.drawPath(leftBottomPath, traAnglePaint);Path rightBottomPath = new Path();rightBottomPath.moveTo(frame.right - triAngleLength, frame.bottom - triAngleWidth / 2);rightBottomPath.lineTo(frame.right - triAngleWidth / 2, frame.bottom - triAngleWidth / 2);rightBottomPath.lineTo(frame.right - triAngleWidth / 2, frame.bottom - triAngleLength);canvas.drawPath(rightBottomPath, traAnglePaint);//循环划线，从上到下if (lineOffsetCount > frame.bottom - frame.top - dp2px(10)) {lineOffsetCount = 0;} else {lineOffsetCount = lineOffsetCount + 6;// canvas.drawLine(frame.left, frame.top + lineOffsetCount, frame.right, frame.top + lineOffsetCount, linePaint); //画一条红色的线Rect lineRect = new Rect();lineRect.left = frame.left;lineRect.top = frame.top + lineOffsetCount;lineRect.right = frame.right;lineRect.bottom = frame.top + dp2px(10) + lineOffsetCount;canvas.drawBitmap(((BitmapDrawable) (getResources().getDrawable(R.mipmap.scanline))).getBitmap(), null, lineRect, linePaint);}postInvalidateDelayed(10L, frame.left, frame.top, frame.right, frame.bottom);}private int dp2px(int dp) {float density = getContext().getResources().getDisplayMetrics().density;return (int) (dp * density + 0.5f);}}
