<分区>
是否可以像这样在 Visual Studio 中创建文本框:
<分区>
是否可以像这样在 Visual Studio 中创建文本框:
最佳答案
其实。更好的解决方案是简单地使用文本框的 Paint 事件来绘制字符串。
代码如下:
class CueTextBox : TextBox
{
public event EventHandler CueTextChanged;
private string _cueText;
public string CueText
{
get { return _cueText; }
set
{
value = value ?? string.Empty;
if (value != _cueText)
{
_cueText = value;
OnCueTextChanged(EventArgs.Empty);
}
}
}
public CueTextBox()
: base()
{
_cueText = string.Empty;
}
protected virtual void OnCueTextChanged(EventArgs e)
{
this.Invalidate(true);
if (this.CueTextChanged != null)
this.CueTextChanged(this, e);
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
if (string.IsNullOrEmpty(this.Text.Trim()) && !string.IsNullOrEmpty(this.CueText) && !this.Focused)
{
Point startingPoint = new Point(0, 0);
StringFormat format = new StringFormat();
Font font = new Font(this.Font.FontFamily.Name, this.Font.Size, FontStyle.Italic);
if (this.RightToLeft == RightToLeft.Yes)
{
format.LineAlignment = StringAlignment.Far;
format.FormatFlags = StringFormatFlags.DirectionRightToLeft;
}
e.Graphics.DrawString(CueText, font, Brushes.Gray, this.ClientRectangle, format);
}
}
const int WM_PAINT = 0x000F;
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_PAINT)
{
this.OnPaint(new PaintEventArgs(Graphics.FromHwnd(m.HWnd), this.ClientRectangle));
}
}
}
现在,您只需将“CueText”属性设置为您想要的初始值即可!
关于c# - 自定义文本框控件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/9247756/