Winform 水印TextBox(近乎完美)
public partial class WaterTextBox : TextBox { private readonly Label lblwaterText = new Label(); public WaterTextBox() { InitializeComponent(); lblwaterText.BorderStyle = BorderStyle.None; lblwaterText.Enabled = false; lblwaterText.BackColor = Color.White; lblwaterText.AutoSize = false; lblwaterText.Top = 1; lblwaterText.Left = 2; lblwaterText.FlatStyle = FlatStyle.System; Controls.Add(lblwaterText); } [Category("扩展属性"), Description("显示的提示信息")] public string WaterText { get { return lblwaterText.Text; } set { lblwaterText.Text = value; } } public override string Text { set { lblwaterText.Visible = value == string.Empty; base.Text = value; } get { return base.Text; } } protected override void OnSizeChanged(EventArgs e) { if (Multiline && (ScrollBars == ScrollBars.Vertical || ScrollBars == ScrollBars.Both)) lblwaterText.Width = Width - 20; else lblwaterText.Width = Width; lblwaterText.Height = Height - 2; base.OnSizeChanged(e); } protected override void OnTextChanged(EventArgs e) { lblwaterText.Visible = base.Text == string.Empty; base.OnTextChanged(e); } protected override void OnMouseDown(MouseEventArgs e) { lblwaterText.Visible = false; base.OnMouseDown(e); } protected override void OnMouseLeave(EventArgs e) { lblwaterText.Visible = base.Text == string.Empty; base.OnMouseLeave(e); } //protected override void OnEnter(EventArgs e) //{ // lblwaterText.Visible = false; // base.OnEnter(e); //} //protected override void OnLeave(EventArgs e) //{ // if (string.IsNullOrEmpty(base.Text)) // lblwaterText.Visible = true; // base.OnLeave(e); //} }
新加一种方法(转):
public partial class PromptTextBox : TextBox
{
private string promptString = string.Empty;
private bool IsEmpty = true;
public PromptTextBox()
{
InitializeComponent();
}
public PromptTextBox(string prompt)
{
InitializeComponent();
PromptString = prompt;
}
/**/
/// <summary>
/// Prompt Text
/// </summary>
public string PromptString
{
get { return promptString; }
set { promptString = value; }
}
protected override void OnEnter(EventArgs e)
{
if (IsEmpty) { Clear(); }
}
protected override void OnLeave(EventArgs e)
{
if (Text == string.Empty)
{
Text = PromptString;
IsEmpty = true;
}
else { IsEmpty = false; }
}
public override string Text
{
get
{
if (IsEmpty) { return string.Empty; }
else { return base.Text; }
}
set
{
if (value == string.Empty)
{
base.Text = PromptString;
IsEmpty = true;
}
else
{
IsEmpty = (value == PromptString);
base.Text = value;
}
}
}
protected override void OnCreateControl()
{
if (Text == string.Empty)
{
Text = PromptString;
IsEmpty = true;
}
else { IsEmpty = false; }
}
}