If you press and hold the 5 key on the numpad it will continue to execute a statement in the KeyDown event handler. How can i ensure the statement is executed only once, even if i hold the key down?
Thanks for your attention.
private void form_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
if (e.KeyCode == Keys.NumPad5)
{
dados.enviar("f"); //I want this to run only once!
}
}
You can set flag on key down and reset it on key up.
private bool isPressed = false;
public Form1()
{
InitializeComponent();
}
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.B && !isPressed )
{
isPressed = true;
// do work
}
}
private void Form1_KeyUp(object sender, KeyEventArgs e)
{
if (isPressed )
isPressed = false;
}
bool alreadyPressed = false;
...
if (e.KeyCode == Keys.NumPad5 && ! alreadyPressed)
{
alreadyPressed = true;
...
您应该使用IsRepeat标志来检查它是否是第一次按下键。
if (e.KeyCode == Keys.NumPad5 && !e.IsRepeat)
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