如果按下键，如何更改布尔值c＃

Question

我试图在按下某个键时更改一个布尔值，但是当释放时返回到false，因此，如果所有参数都正确并且按下某个键，则只能触发if语句。

public class boolean
{
    public static Boolean keyPresed = false;
}

private void mainForm_KeyDown(object sender, KeyEventArgs e)
{                
    if (e.KeyData == Keys.A)
    {
        MessageBox.Show(" just for debugging ");
        boolean.keyPresed = true;
     } 
      else {
          boolean.keyPressed = false;
         }
        if (tileBuyPlayer2.Checked && ownerShipsPlayer2.peacockOwner == false && boolean.keyPresed == true)
        {
            // do this sorry not on here cause how big it is
        }
    }
}

Answer 1

您可以global var in this class 中将keyAPressed声明为global var in this class 变量 ，并在KeyDown事件中将其reset ：

public class DemoClass
{
    public static Boolean keyAPressed = false;

    private void mainForm_KeyDown(object sender, KeyEventArgs e)
    {                
        if (e.KeyCode == Keys.A)
        {
            MessageBox.Show(" just for debugging ");
            keyAPressed = true;
        } 
        else 
        {
            keyAPressed = false;
        }
        if (keyAPressed == true)
        {
            // Reset keyAPressed to false
            keyAPressed = false
            if (tileBuyPlayer2.Checked && ownerShipsPlayer2.peacockOwner == false)
            {
                // do this sorry not on here cause how big it is
            }
        }
    }
}

或使用KeyUp事件reset keyAPressed ：

public class DemoClass
{
    public static Boolean keyAPressed = false;

    private void mainForm_KeyDown(object sender, KeyEventArgs e)
    {                
        if (e.KeyCode == Keys.A)
        {
            MessageBox.Show(" just for debugging ");
            keyAPressed = true;
        } 
        else 
        {
            keyAPressed = false;
        }

        if (tileBuyPlayer2.Checked && ownerShipsPlayer2.peacockOwner == false && keyAPressed == true)
        {
            // do this sorry not on here cause how big it is
        }
    }
    private void mainForm_KeyUp(object sender, KeyEventArgs e)
    {
        keyAPressed = false;
    }
}

Answer 2

如果您乐于尝试使用Microsoft的反应框架，则可以尝试执行以下操作：

var keyDown = Observable.FromEventPattern<KeyEventArgs>(mainForm, "KeyDown");

var query =
    from kd in keyDown
    where kd.EventArgs.KeyCode == Keys.A
    where tileBuyPlayer2.Checked
    where ownerShipsPlayer2.peacockOwner == false
    select kd;

query.Subscribe(x =>
{
    // do your code here
});

我可能错过了您想要做的事情，但是我认为这使事情变得容易得多。