【发布时间】：2013-03-09 20:40:13
【问题描述】：
我有一个以图片为背景的图片框（实际上是一张地图），我在其上生成矩形。这些矩形应该移动给定的点。矩形以指定的速度移动，在到达（或接近）其中一个点后，它开始移动到下一个点。然而我的问题是，矩形并没有直接移动到给定点，它只是继续接近其中一个坐标，所以在某些情况下，矩形的 Y 坐标和点的 Y 坐标是一样，但矩形是 60 像素，不会移动。 下面我添加一张图片作为运动的例子。蓝色是预期路线，红色是实际路线。我已经检查了一百次坐标，它们是正确的，矩形只是在其他地方移动。注意：这只发生在某些地方。
这是我用来计算矩形相对于 X 轴和 Y 轴的移动的代码。
public void Move_calculate(Graphics g)
{
if (points[passed].X == 0 || points[passed].Y == 0) // this happens when the rectangle reaches it final point - it stays where it is (working fine)
{
Redraw(g);
return;
}
speed = randomNumbers.Next(7, 13);
if (points[passed].X > x_coordinate && points[passed].Y > y_coordinate)
{
Bx = points[passed].X;
By = points[passed].Y;
distanceForAlfaX = Bx - x_coordinate; // x_coordinate is the x coordinate of the rectangle
distanceForAlfaY = By - y_coordinate;
if (distanceForAlfaX <= 20 || distanceForAlfaY <= 20) speed = 5; // slowing down when approaching the point
if (distanceForAlfaX + distanceForAlfaY <= 15) passed += 1;
alpha = (distanceForAlfaY / distanceForAlfaX); // tangent alpha
x_change = (int)(speed * (Math.Cos(alpha))); // get distance moved relative to axis X
y_change = (int)Math.Sqrt(((speed * speed) + (x_change * x_change))); // again distance for axis Y, using Pythagoras theorem
x_coordinate += x_change;
y_coordinate += y_change;
}
else if (points[passed].X > x_coordinate && points[passed].Y < y_coordinate)
{
Bx = points[passed].X;
By = points[passed].Y;
distanceForAlfaX = Bx - x_coordinate;
distanceForAlfaY = y_coordinate - By;
if (distanceForAlfaX <= 20 || distanceForAlfaY <= 20) speed = 5;
if (distanceForAlfaX + distanceForAlfaY <= 15) passed += 1;
alpha = (distanceForAlfaY / distanceForAlfaX);
x_change = (int)(speed * (Math.Cos(alpha)));
y_change = (int)Math.Sqrt(((speed * speed) + (x_change * x_change)));
x_coordinate += x_change;
y_coordinate -= y_change;
}
else if (points[passed].X < x_coordinate && points[passed].Y > y_coordinate)
{
Bx = points[passed].X;
By = points[passed].Y;
distanceForAlfaX = x_coordinate - Bx;
distanceForAlfaY = By - y_coordinate;
if (distanceForAlfaX <= 20 || distanceForAlfaY <= 20) speed = 5;
if (distanceForAlfaX+distanceForAlfaY <= 15) passed += 1;
alpha = (distanceForAlfaY / distanceForAlfaX);
x_change = (int)(speed * (Math.Cos(alpha)));
y_change = (int)Math.Sqrt(((speed * speed) + (x_change * x_change)));
x_coordinate -= x_change;
y_coordinate += y_change;
}
else if (points[passed].X < x_coordinate && points[passed].Y < y_coordinate)
{
Bx = points[passed].X;
By = points[passed].Y;
distanceForAlfaX = x_coordinate - Bx;
distanceForAlfaY = y_coordinate - By;
if (distanceForAlfaX <= 20 || distanceForAlfaY <= 20) speed = 5;
if (distanceForAlfaX + distanceForAlfaY <= 15) passed += 1;
alpha = (distanceForAlfaY / distanceForAlfaX);
x_change = (int)(speed * (Math.Cos(alpha)));
y_change = (int)Math.Sqrt(((speed * speed) + (x_change * x_change)));
x_coordinate -= x_change;
y_coordinate -= y_change;
}
else
{
MessageBox.Show("Something went wrong"); // just notify me that it isnt working again..
}
Pen p = new Pen(Color.Turquoise, 2);
r = new Rectangle(x_coordinate, y_coordinate, 5, 5); // redraw the rectangle
g.DrawRectangle(p, r);
p.Dispose();
}
我不知道为什么会发生这种情况，有人可以帮忙吗？ 附言 运动绝对不需要平滑，矩形的位置将使用定时器每两秒更新一次。现在它暂时设置为一个按钮。
编辑： 这是foreach代码。标签只是图片框旁边显示的坐标
foreach (aircraft acft in aircrafts) // aircraft is an array aircrafts[]
{
label2.Text = "xp" + acft.points[acft.passed].X;
label3.Text = "yp" + acft.points[acft.passed].Y;
label4.Text = acft.passed.ToString();
label5.Text = "y" + acft.y_coordinate.ToString();
//MessageBox.Show(acft.points[0].X.ToString());
acft.Move_calculate(e.Graphics);
spawn = string.Empty;
}
EDIT2：aircraft 类中的所有变量
public string callsign;
public int speed;
public double heading;
public bool moving = false;
public Point[] points;
public double alpha;
public int x_change;
public int y_change;
public int x_coordinate;
public int y_coordinate;
public int Bx;
public int By;
public double distanceForAlfaX;
public double distanceForAlfaY;
public int passed = 0;
public Rectangle r;
【问题讨论】：
-
要检查坐标，在 PictureBox 旁边我还显示当前坐标、经过的点和下一个点的坐标。当矩形像到达终点时，它通常完全在其他地方。如果需要，我可以分享整个代码，现在大约 300 行长。
-
这个方法是循环调用还是什么？一旦到达某个点/点，还有什么会触发点移动..？看起来你缺少一些相关的代码..
-
这个方法是从 PictureBox1.Paint 在 foreach 循环中调用的（对于每个矩形）。点击按钮后触发PictureBox1.Paint（按钮使PictureBox失效）
-
您应该显示 foreach 循环代码，这将有助于查看您在该循环中所做的事情。我还注意到您是
Unregistering Events with thex_coordinate -= x_change;` ...等等其中一个可能会导致问题.. -
'if' 块中有大量不必要的代码重复。考虑重构它以删除重复，您将更有可能找到您的错误并避免未来的错误。