c# - XNA，Do-While 基本问题

Question

我正在为我的 XNA 项目创建一个简单的 AI。

我的敌人应该在短时间后从右移到左。

不幸的是，我的代码跳过了我的第一次和第二次 Do-While，所以我的敌人没有移动:< 5 秒长。所以他只是从 +-1.X 位置跳

while (i <= 1)
    {
        EnemyVelocity.X += 1f;
        timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
        usedTimeRight = timer;
        i++;
    } 

    if (usedTimeRight != 0) 
    {
        do
        { EnemyVelocity.X -= 1f;
          timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
        } while ((timer - usedTimeRight) >= 5);
        usedTimeLeft = timer;
        usedTimeRight = 0;
    }
    if (usedTimeLeft != 0)
    {
        do
        { EnemyVelocity.X += 1f;
          timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
        }
        while (timer - usedTimeLeft >= 5);
        usedTimeRight = timer;
        usedTimeLeft= 0;
    }

更新了...~~~~~~~~~~~

那么，现在另一个问题 - 我的敌人一直在向左移动

timer += (float)gameTime.ElapsedGameTime.TotalSeconds;

while (i <= 1)
    {
        EnemyVelocity.X -= 1f;
        timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
        usedTimeRight = timer;
        i++;
    }

    if (usedTimeRight != 0 && (timer - usedTimeRight <= 2))
    { 
        int x;

        for (x = 0; x <= 3; x++)
        {
            EnemyVelocity.X = 1;

        }
        usedTimeLeft = timer;
        usedTimeRight = 0;
    }
  if (usedTimeLeft != 0 && (timer - usedTimeLeft <= 2))
    {
        int x;

        for (x = 0; x <= 3; x++)
        {
            EnemyVelocity.X = - 1;

        }
        usedTimeRight = timer;
        usedTimeLeft = 0;
    }

Answer 1

问题在于初始的 while 循环迭代速度如此之快以致于 while 循环在 usedTimeRight = timer > 0 之前退出。这意味着您的 fist 和 second if 语句将为 false因为 useTimeLeft 和 useTimeRight 将始终为 0。尝试更改它，以便 Timer 变量在声明时等于 1。

例如:

  float timer = 1f;

  while (i <= 1 ) 
            {
                EnemyVelocity.X += 1f;
                timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
                usedTimeRight = timer;
                i++;
            } 


            if (usedTimeRight != 0) 
            {
                do
                { EnemyVelocity.X -= 1f;
                  timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
                } while ((timer - usedTimeRight) >= 5);
                usedTimeLeft = timer;
                usedTimeRight = 0;
            }
            if (usedTimeLeft != 0)
            {
                do
                { EnemyVelocity.X += 1f;
                  timer += (float)gameTime.ElapsedGameTime.TotalSeconds;
                }
                while (timer - usedTimeLeft >= 5);
                usedTimeRight = timer;
                usedTimeLeft= 0;
            }