KeyDown和keyUp事件,以避免文本框控件中的重复字母

Question

我的问题是:

如何使用C#禁用在文本框控件中按住键？例如Boxxxxxxxxxxxxxxxxxxxxx

我不想让用户从键盘上重复任何字符.

有什么建议吗？

谢谢

Answer 1

您可以在 KeyEventArgs 上使用 SupressKeyPress 属性：

public partial class Form1 : Form
{
    private bool isKeyPressed = false;
    public Form1()
    {
        InitializeComponent();
        this.textBox1.KeyDown += new KeyEventHandler(textBox1_KeyDown);
        this.textBox1.KeyUp += new KeyEventHandler(textBox1_KeyUp);
    }

    void textBox1_KeyUp(object sender, KeyEventArgs e)
    {
        isKeyPressed = false;
    }

    void textBox1_KeyDown(object sender, KeyEventArgs e)
    {
        e.SuppressKeyPress = isKeyPressed;
        isKeyPressed = true;
    }


}

Answer 2

只是为每个人使用KeyDown和KeyUp事件来抑制键重复的额外注释.如果你这样做,你需要排除捕获元键,如Alt/Shift等,否则当按下那些键时,你想要的实际键将不会发送,因为这是一个两个组合键,KeyDown和KeyUp事件捕获所有键.

这适用于所有双键组合.我没有将所有元键添加到以下示例中,只是最常见的.您可以通过将自己的密钥添加到集合中来轻松添加自己的密钥.扩展BFree的帖子:

public partial class Form1 : Form
{
    private static readonly System.Collections.Generic.ICollection<System.Windows.Forms.Keys) ExcludeKeys = new System.Collections.Generic.HashSet<System.Windows.Forms.Keys)()
    {
        System.Windows.Forms.Keys.None,
        System.Windows.Forms.Keys.Shift,
        System.Windows.Forms.Keys.ShiftKey,
        System.Windows.Forms.Keys.LShiftKey,
        System.Windows.Forms.Keys.RShiftKey,
        System.Windows.Forms.Keys.Alt,
        System.Windows.Forms.Keys.Control,
        System.Windows.Forms.Keys.ControlKey,
        System.Windows.Forms.Keys.LControlKey,
        System.Windows.Forms.Keys.RControlKey,
        System.Windows.Forms.Keys.CapsLock,
        System.Windows.Forms.Keys.NumLock,
        System.Windows.Forms.Keys.LWin,
        System.Windows.Forms.Keys.RWin
    }

    private bool isKeyPressed = false;
    public Form1()
    {
        InitializeComponent();
        this.textBox1.KeyDown += new KeyEventHandler(textBox1_KeyDown);
        this.textBox1.KeyUp += new KeyEventHandler(textBox1_KeyUp);
    }

    void textBox1_KeyUp(object sender, KeyEventArgs e)
    {
        if (!ExcludeKeys.Contains(e.KeyCode))
        {
            isKeyPressed = false;
        }
    }

    void textBox1_KeyDown(object sender, KeyEventArgs e)
    {
        if (!ExcludeKeys.Contains(e.KeyCode))
        {
            e.SuppressKeyPress = isKeyPressed;
            isKeyPressed = true;
        }
    }
}