按下选项卡在文本框之间不会更改

时间:2017-05-16 20:28:38

标签: c# winforms

我有一个名为“PlaceholderTextBox”的类,它可以作为带有占位符文本的文本框:

internal class PlaceholderTextBox : TextBox
{
    private bool isPlaceHolder = true;
    private bool isPassword;
    private string _PlaceholderText;
    private string _InputText;

    public string PlacehoderText
    {
        get { return _PlaceholderText; }
        set { _PlaceholderText = value; setPlaceholder(); }
    }

    public string InputText
    {
        get { return _InputText; }
        set { _InputText = value; }
    }

    public bool IsPassword
    {
        get { return isPassword; }
        set { isPassword = value; }
    }

    private void setPlaceholder()
    {
        if (string.IsNullOrEmpty(this.Text))
        {
            this.Text = PlacehoderText;
            InputText = "";
            this.ForeColor = System.Drawing.Color.Gray;
            isPlaceHolder = true;
            if (isPassword) this.UseSystemPasswordChar = false;
        }
    }

    private void removePlaceHolder()
    {
        if (isPlaceHolder)
        {
            this.Text = "";
            this.ForeColor = System.Drawing.SystemColors.WindowText;
            isPlaceHolder = false;
            if (isPassword) this.UseSystemPasswordChar = true;
        }
    }

    public void resetText()
    {
        isPlaceHolder = true;
        this.Text = null;
        setPlaceholder();
    }

    public PlaceholderTextBox()
    {
        Enter += removePlaceHolder;
        Leave += setPlaceholder;
        TextChanged += addText;
    }

    private void setPlaceholder(object sender, EventArgs e)
    {
        setPlaceholder();
    }

    private void removePlaceHolder(object sender, EventArgs e)
    {
        removePlaceHolder();
    }

    private void addText(object sender, EventArgs e)
    {
        InputText = this.Text;
    }
}

在我的主窗体中,我有两个这样的PlaceholderTextBox,一个用于“用户名”,另一个用于“密码”,它还有用于保护输入文本的子弹覆盖。我发现的问题是,如果我想使用“Tab”键从密码文本框切换到另一个,它不起作用。如果它有一些文本或我想从用户名切换到密码,它工作正常,但如果我在密码框中没有任何文本,我想切换到用户名,它不起作用。

我完全不知道为什么不工作,我的猜测是它与密码封面系统有关。关于这个问题的任何见解?

0 个答案:

没有答案