iOS 扫描上的层及其样式（二）

要实现上一个图中的扫描区域4个角，可以用以下代码实现

1、新建一个view。

2、将将扫描区域的CGRect传进来。

3、利用

-(void)drawRect:(CGRect)rect方法
4、调整下四个角的所在区域，控制了角的宽和高，

//单个角的两线间距

#define klineDistance 10

//角的宽度

#define cornerWith 30
<
4000
p style="margin-top:0px;margin-bottom:0px;font-size:11px;font-family:'Heiti SC Light';color:rgb(0,132,0);">
//角的高度

#define cornerHeight 30

-(void)drawRect:(CGRect)rect
{

    [selfleftUpCorner];

    [selfrightUpCorner];

    [selfrightBottonCorner];

    [selfleftBottonCorner];
}

#pragma mark -左上角
-(void)leftUpCorner
{

    UIBezierPath *path = [UIBezierPath
bezierPath];

    
   
CGFloat x = 2;
   
CGFloat y = 2;

    

    [path moveToPoint:CGPointMake(x, y)];
//起始点

    [path addLineToPoint:CGPointMake(cornerWith + x, y)];
    [path
addLineToPoint:CGPointMake(cornerWith + x, y +
klineDistance)];

    [path addLineToPoint:CGPointMake(klineDistance + x,
y + klineDistance)];

    [path addLineToPoint:CGPointMake(klineDistance + x,cornerHeight
+ y)];

    [path addLineToPoint:CGPointMake(x,
cornerHeight + y)];
    [path
closePath];

    

    //获取当前环境

    CGContextRef context =
UIGraphicsGetCurrentContext();

    //保存当前环境，便于以后恢复

    CGContextSaveGState(context);

    

    //将坐标的起点

    CGContextTranslateCTM(context,
0, 0);

    //将当前的颜色变成黄色
   
UIColor* fillColor = [UIColor
redColor];
    [fillColor
setFill];

    //五角星填充为黄色
    [path
fill];

    

    CGContextRestoreGState(context);
}

#pragma mark -右上角
-(void)rightUpCorner
{

    UIBezierPath *path = [UIBezierPath
bezierPath];

    
   
CGSize size = self.rect.size;

    
   
CGFloat x = size.width -
cornerWith - 2;
   
CGFloat y = 2;

    

    [path moveToPoint:CGPointMake(x, y)];
//起始点

    [path addLineToPoint:CGPointMake(x +
cornerWith, y)];
    [path
addLineToPoint:CGPointMake(x +
cornerWith , y + cornerHeight)];

    [path addLineToPoint:CGPointMake(x +
cornerWith - klineDistance , y +
cornerHeight)];

    [path addLineToPoint:CGPointMake(x +
cornerWith - klineDistance , y +
klineDistance)];

    [path addLineToPoint:CGPointMake(x , y +
klineDistance)];
    [path
closePath];

    

    //获取当前环境

    CGContextRef context =
UIGraphicsGetCurrentContext();

    //保存当前环境，便于以后恢复

    CGContextSaveGState(context);

    

    //将坐标的起点变成（100，100）

    CGContextTranslateCTM(context,
0, 0);

    //将当前的颜色变成黄色
   
UIColor* fillColor = [UIColor
redColor];
    [fillColor
setFill];

    //五角星填充为黄色
    [path
fill];

    

    CGContextRestoreGState(context);
}

#pragma mark -右下角
-(void)rightBottonCorner
{

    UIBezierPath *path = [UIBezierPath
bezierPath];

    
   
CGSize size = self.rect.size;

    
   
CGFloat x = size.width -
cornerWith - 2;
   
CGFloat y = size.height -
cornerHeight - 2;

    
    [path
moveToPoint:CGPointMake(x +
cornerWith - klineDistance, y)];
//起始点

    [path addLineToPoint:CGPointMake(x +
cornerWith , y)];
    [path
addLineToPoint:CGPointMake(x +
cornerWith , y + cornerHeight)];

    [path addLineToPoint:CGPointMake(x , y +
cornerHeight)];
    [path
addLineToPoint:CGPointMake(x , y +
cornerHeight - klineDistance)];

    [path addLineToPoint:CGPointMake(x +
cornerWith - klineDistance , y +
cornerHeight - klineDistance)];
    [path
closePath];

    

    //获取当前环境

    CGContextRef context =
UIGraphicsGetCurrentContext();

    //保存当前环境，便于以后恢复

    CGContextSaveGState(context);

    

    CGContextTranslateCTM(context,
0, 0);

    //将当前的颜色变成黄色
   
UIColor* fillColor = [UIColor
redColor];
    [fillColor
setFill];

    //五角星填充为黄色
    [path
fill];

    

    CGContextRestoreGState(context);
}

#pragma mark -左下角
-(void)leftBottonCorner
{

    UIBezierPath *path = [UIBezierPath
bezierPath];

    
   
CGSize size = self.rect.size;

    
   
CGFloat x = 2;
   
CGFloat y = size.height -
cornerHeight - 2;

    

    [path moveToPoint:CGPointMake(x , y)];
//起始点

    [path addLineToPoint:CGPointMake(x +
klineDistance , y)];

    [path addLineToPoint:CGPointMake(x +
klineDistance , y + cornerHeight -
klineDistance)];

    [path addLineToPoint:CGPointMake(x +
cornerWith , y + cornerHeight -
klineDistance)];
    [path
addLineToPoint:CGPointMake(x +
cornerWith , y + cornerHeight)];

    [path addLineToPoint:CGPointMake(x , y +
cornerHeight)];
    [path
closePath];

    

    //获取当前环境

    CGContextRef context =
UIGraphicsGetCurrentContext();

    //保存当前环境，便于以后恢复

    CGContextSaveGState(context);

    

    //将坐标的起点变成（100，100）

    CGContextTranslateCTM(context,
0, 0);

    //将当前的颜色变成黄色
   
UIColor* fillColor = [UIColor
redColor];
    [fillColor
setFill];

    //五角星填充为黄色
    [path
fill];

    

    CGContextRestoreGState(context);
}