c# - 运动检测'if''语句

Question

我一直在写这个运动检测程序，遇到了“if语句”的问题，代码如下：

       for (int i = 0; i < frameSize; i++, backFrame++, currFrame++)
            {
                // difference
                diff = ((int)*currFrame) - ((int)*backFrame);
               // threshold
                if ((diff >= differenceThreshold) || (diff <= differenceThresholdNeg))
                {
                    *currFrame = (byte)255;
                    if (i < 640)
                    {
                        x[i] = i;
                        y[i] = 0;
                    }
                    else
                    {
                        x[i] = i % 640;
                        y[i] = i / 640;
                    }
                    if (xMax < x[i]) xMax = x[i];
                    if (xMin > x[i]) xMin = x[i];
                    if (yMax < y[i]) yMax = y[i];
                    if (yMin > y[i]) yMin = y[i];
                    xC = ((xMax - xMin) / 2) + xMin;
                    yC = ((yMax - yMin) / 2) + yMin; 
                }
                else
                {
                    *currFrame = (byte)0;
                }
             }

问题是它在“if”之后跳过代码并执行“else”，即使条件

(((diff >= differenceThreshold) || (diff <= differenceThresholdNeg))) is true.

我是 C# 的新手，所以有人可以帮助我吗？