                             arrTraces![i].arrPoints.append(point)
                             break
                         }
+                        i += 1
                     }
                     self .setNeedsDisplay()
                 }

                    let point = touchPoint.locationInView(self)
                    //怎么找到上一个Point
                    let previousPoint = touchPoint.previousLocationInView(self)
                    for var i=0;i<arrTraces?.count;i += 1
                    {
                        var tempTraces = arrTraces![i]
                        let lastPoint = tempTraces.arrPoints.last
                        if lastPoint == previousPoint

        if arrTraces?.count > 0
        {
            CGContextBeginPath(ctg)
            var i = 0
            while i < arrTraces?.count {
                var tempTrace = arrTraces![i]
                if tempTrace.arrPoints.count > 0
                {
