程序没有捕获密钥

正如标题所说，我的程序有问题。我创造了一个功能(游戏邦注:一个战斗功能，玩家可以在textbox中编写并按下按钮)。战斗结束后，我的程序没有捕获按下的键，除非我在程序中再次使用alt-tab和alt-tab。我该怎么做?

//capture key function     
private void joc_KeyDown_1(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.F4 && e.Alt && permite_pasi == true)
    {
        enableClose = false;
    }
    if (e.KeyCode == Keys.D || e.KeyCode == Keys.Right && permite_pasi == true)
    {
        step(6); //step() is the movement function
    }
    if (e.KeyCode == Keys.W || e.KeyCode == Keys.Up && permite_pasi == true)
    {
        step(8);
    }
    if (e.KeyCode == Keys.A || e.KeyCode == Keys.Left && permite_pasi == true)
    {
        step(4);
    }
    if (e.KeyCode == Keys.S || e.KeyCode == Keys.Down && permite_pasi == true)
    {
        step(2);
    }
}
//movement function
public void step(int directie)
{
    if (directie == 6 && checkstep(directie) == true) { //checkstep() is a function which check the environment for obstacles
        if (check_NPC(jucator.x, jucator.y) > 0) // function for checking the environment
        {
            scorenpc = check_NPC(jucator.x, jucator.y); //some variabile
            NPC(check_NPC(jucator.x, jucator.y), jucator.score); // the battle function
        }
        else
        {
            //movement instructions
        }
    }
    if (directie == 4 && checkstep(directie) == true)
    {
        if (check_NPC(jucator.x, jucator.y) != 0)
        {
            scorenpc = check_NPC(jucator.x, jucator.y);
            NPC(check_NPC(jucator.x, jucator.y), jucator.score);
        }
        else
        {
            //movement instructions
        }
    }
    if (directie == 8 && checkstep(directie) == true)
    {
        if (check_NPC(jucator.x, jucator.y) > 0)
        {
            scorenpc = check_NPC(jucator.x, jucator.y);
            NPC(check_NPC(jucator.x, jucator.y), jucator.score);
        }
        else
        {
            //movement instructions
        }
    }
    if (directie == 2 && checkstep(directie) == true)
    {
        if (check_NPC(jucator.x, jucator.y) != 0)
        {
            scorenpc = check_NPC(jucator.x, jucator.y);
            NPC(check_NPC(jucator.x, jucator.y), jucator.score);
        }
        else
        {
            //movement instructions
        }
    }
}

如果有必要的话，我将把剩下的代码放在下次编辑中。