我在 Form1 上有一个按钮，如果 Form2 没有打开，它会打开 Form2(Leaderboard)。我想要做的是：单击按钮，如果 Form2 已关闭，则打开 Form2。否则 Form2 已打开，请将 Form2 置于最前面。
使用下面的代码，当 leaderboardOpen == true; 什么都不做时单击按钮。
public static bool leaderboardOpen = false;
private void leaderButton_Click(object sender, EventArgs e)
{
if (leaderboardOpen == false)
{
Leaderboard leaderboard = new Leaderboard();
leaderboard.Show();
leaderboardOpen = true;
}
else
{
Leaderboard leaderboard = new Leaderboard();
//Tried the below
//leaderboard.Focus();
//leaderboard.BringToFront();
//leaderboard.TopMost = true;
//leaderboard.Activate();
}
}回答1
保留对您的 Leaderboard 实例本身的引用，而不是布尔值：
private Leaderboard leader = null;
private void leaderButton_Click(object sender, EventArgs e)
{
if (leader == null || leader.IsDisposed)
{
leader = new Leaderboard();
leader.FormClosed += (s2, e2) => { leader = null; };
leader.Show();
}
else
{
if (leader.WindowState == FormWindowState.Minimized)
{
leader.WindowState = FormWindowState.Normal;
}
leader.BringToFront();
}
}回答2
让它与下面的代码一起工作。
private void leaderButton_Click(object sender, EventArgs e)
{
var form = Application.OpenForms.OfType<Leaderboard>().FirstOrDefault();
if (form != null)
{
form.Activate();
}
else
{
new Leaderboard().Show();
}
}回答3
这是我的工作代码
public static bool leaderboardOpen = false;
public static Leaderboard? leaderboardForm = null;
private void leaderButton_Click(object sender, EventArgs e)
{
if (!leaderboardOpened || leaderboardForm is null)
{
// Initialize Leaderboard form if it doesn't exist
leaderboardForm = new Leaderboard();
leaderboardForm.Show();
leaderboardOpened = true;
}
else
{
// Focus on the form
leaderboardForm.Focus();
}
}如果排行榜表单已关闭，请确保制作 leaderboardOpened = false;。