android二维码扫描界面绘制demo

package com.mcj.codescan;
import com.mcj.android.camera.CameraManager;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;
public class CaptureRectView extends View {
public final static int scanStep = 5;
public final static long INVALI_DELAY_TIME = 50;
public int scanLineBase;
private Paint mpaint;
private Rect frameRect;// 矩形框坐标，以activity方向为基准坐标
private int screanHeight;// 窗口高度，以activity方向为基准
private int screanWidth;// 窗口宽度，以activity方向为基准
public CaptureRectView(Context context, AttributeSet attrs) {
super(context, attrs);
mpaint = new Paint();
scanLineBase = 1;
}
@Override
protected void onDraw(Canvas canvas) {
frameRect = CameraManager.get().getFramingRect();
if (frameRect == null
|| CameraManager.get().getConfigManager().getScreenResolution() == null) return;
if (screanWidth == 0 || screanHeight == 0) {
screanWidth = CameraManager.get().getConfigManager()
.getScreenResolution().x;
screanHeight = CameraManager.get().getConfigManager()
.getScreenResolution().y;
}
drawBox(canvas);
drawFocusBox(canvas);
drawShadow(canvas);
drawScanLine(canvas);
postInvalidateDelayed(INVALI_DELAY_TIME, frameRect.left, frameRect.top,
frameRect.right, frameRect.bottom);
super.onDraw(canvas);
}
/**
* 绘制黑色外框
*
* @param canvas
*/
private void drawBox(Canvas canvas) {
mpaint.setARGB(255, 0, 0, 0);
mpaint.setStyle(Paint.Style.FILL);
mpaint.setStrokeWidth(2.0f);
canvas.drawRect(frameRect.left, frameRect.top, frameRect.right + 1, frameRect.top + 2, mpaint);
canvas.drawRect(frameRect.left, frameRect.top + 2, frameRect.left + 2, frameRect.bottom - 1, mpaint);
canvas.drawRect(frameRect.right - 1, frameRect.top,
frameRect.right + 1, frameRect.bottom - 1, mpaint);
canvas.drawRect(frameRect.left, frameRect.bottom - 1,
frameRect.right + 1, frameRect.bottom + 1, mpaint);
}
/**
* 绘制绿色聚焦框
*
* @param canvas
*/
private void drawFocusBox(Canvas canvas) {
float strokeWidth = 5.0f;
mpaint.setARGB(255, 0, 255, 0);
mpaint.setStyle(Paint.Style.FILL);
mpaint.setStrokeWidth(strokeWidth);
float left = frameRect.left - strokeWidth;
float right = frameRect.right + strokeWidth;
float top = frameRect.top - strokeWidth;
float buttom = frameRect.bottom + strokeWidth;
float length = 0.1f * screanWidth;
canvas.drawLine(left - strokeWidth / 2, top, left + length, top, mpaint);
canvas.drawLine(left, top - strokeWidth / 2, left, top + length, mpaint);
canvas.drawLine(right + strokeWidth / 2, top, right - length, top,
mpaint);
canvas.drawLine(right, top - strokeWidth / 2, right, top + length,
mpaint);
canvas.drawLine(left - strokeWidth / 2, buttom, left + length, buttom, mpaint);
canvas.drawLine(left, buttom + strokeWidth / 2, left, buttom - length, mpaint);
canvas.drawLine(right + strokeWidth / 2, buttom, right - length,
buttom, mpaint);
canvas.drawLine(right, buttom + strokeWidth / 2, right,
buttom - length, mpaint);
}
/**
* 绘制box外阴影
*
* @param canvas
*/
private void drawShadow(Canvas canvas) {
mpaint.setARGB(150, 0, 0, 0);
mpaint.setStyle(Paint.Style.FILL);
mpaint.setStrokeWidth(4.0f);
canvas.drawRect(0, 0, frameRect.left, screanHeight, mpaint);
canvas.drawRect(frameRect.left, 0, frameRect.right, frameRect.top,
mpaint);
canvas.drawRect(frameRect.left, frameRect.bottom, frameRect.right, screanHeight, mpaint);
canvas.drawRect(frameRect.right, 0, screanWidth, screanHeight, mpaint); }
/**
* 画扫描线
*
* @param canvas
*/
private void drawScanLine(Canvas canvas) {
int alpha = 255;
mpaint.setStyle(Paint.Style.FILL);
mpaint.setStrokeWidth(1.0f);
for (int sacnShadow = 0; sacnShadow < 51; sacnShadow++) {
if (scanLineBase - sacnShadow < 0)
break;
mpaint.setARGB(alpha, 0, 255, 0);
canvas.drawLine(frameRect.left + 1, frameRect.top + scanLineBase
- sacnShadow, frameRect.right - 1, frameRect.top
+ scanLineBase - sacnShadow, mpaint);
alpha = alpha - 5;
}
scanLineBase = (scanLineBase + scanStep) % (frameRect.height());
}
}。