PROSAGA码农传奇-模型可视化-C＃ - 防止图片框离开边界

<div class =“post-text”itemprop =“text”>
  
    有一些观点与你的代码不一致，至少我是这么认为的。
  
  <OL>
    <LI>
      
        你总是将玩家移动到他的新位置。你确实检查他是否触及边界。如果他触及边界，则向上移动一个像素，向左移动一个像素，然后将7个像素移动到所选择的方向。
所以在里面
         <code>
 if
 </code>
         在那里你检查他是否触及边界你必须中断并且不执行设置新位置的其余代码。一个简单的
         <code>
 return;
 </code>
         会做的。
      
    </LI>
    <LI>
      
        如果按下某个键，您可以检查边界检查，如果玩家没有触及边界，您将移动玩家。这是错误的订单。您必须检查玩家是否会在移动后触摸边界，并且只有当他不接触边界时才移动他。否则你会把他带到边界，再也不会让他出局。
      
    </LI>
  </醇>
  
    所以这里是你的代码有一些更正：
  
   <pre>
 <code>
 private void HorrorForm_KeyDown(object sender, KeyEventArgs e)
{
 int x = player.Location.X;
 int y = player.Location.Y;

if (e.KeyCode == Keys.D)
        x += 7;
    if (e.KeyCode == Keys.A)
        x -= 7;
    if (e.KeyCode == Keys.S)
        y += 7;
    if (e.KeyCode == Keys.W)
        y -= 7;

var tempPlayerPosition= player.Bounds; // get the players position and remember it temporary
    tempPlayerPosition.X = x; // change the players temporary pisition to the new one that it will have after the move
    tempPlayerPosition.Y = y;

//check if the play would touch the boundyries if we use the new temporary pisition
    if (tempPlayerPosition.IntersectsWith(openspot1.Bounds) || 
        tempPlayerPosition.IntersectsWith(openspot2.Bounds) || 
        tempPlayerPosition.IntersectsWith(openspot3.Bounds) || 
        tempPlayerPosition.IntersectsWith(openspot4.Bounds))
    {
        return; //if he would touch the boundary, then do nothing
    }

player.Location = new Point(x, y); //if he would not touch the boundary, move him to his new location
}

</code>
 </pre>
  
    但也许你也想
  
  <UL>
    <LI>
      如果按下的键不是W，S，A或D，则防止执行代码（即使他没有改变任何值）。
    </LI>
    <LI>
      使用
       <code>
 switch
 </code>
       代替
       <code>
 if
 </code>
       这使它更具可读性。
    </LI>
    <LI>
      而不是每次写入数字7，使用局部变量，因此如果将来更改它，您只需要更改一个值。
    </LI>
  </UL>
  
    所以我的推荐看起来像这样：
  
   <pre>
 <code>
 private void HorrorForm_KeyDown(object sender, KeyEventArgs e)
{ 
 var oneStep = 7; // define the amount of pixel the player will be moved
 var tempPlayerPosition = player.Bounds;// get the players position and remember it temporary

switch (e.KeyCode) // check which key was presses
    {
        case Keys.D:
            tempPlayerPosition.X += oneStep; // move right
            break;
        case Keys.A:
            tempPlayerPosition.X -= oneStep; // move left
            break;
        case Keys.S:
            tempPlayerPosition.Y += oneStep; // move down
            break;
        case Keys.W:
            tempPlayerPosition.Y -= oneStep; // move up
            break;
         default: // you may wan't to do nothing if there any other key presses...
            return;
    }

player.Location = new Point(tempPlayerPosition.X, tempPlayerPosition.Y);   //if he would not touch the boundary, move him to his new location
}

</code>
 </pre>
  
    这对你有帮助吗？
  
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