Question

我一直在寻找解决方案，但我似乎无法找到一个，但我想这可能很简单。
我已经构建了一个带有属性的自定义控件类。 当我更改任何此类属性时，我的控件不会自动刷新（既不是在设计器中也不是以编程方式）。有没有办法强制使用Invalidate（）方法？
我已经按照我发现的一些提示，但似乎没有任何工作。
这是一个代码示例来演示我正在经历的事情。
这是我的自定义类型。

[TypeConverter(typeof(ExpandableObjectConverter))]
public class TextComponent
{
    public TextComponent()
    {
        Text= string.Empty;
        Font = Control.DefaultFont;
        ForeColor = Control.DefaultForeColor;
    }

    [NotifyParentProperty(true)]
    public string Text { get; set; }

    [NotifyParentProperty(true)]
    public Font Font { get; set; }

    [NotifyParentProperty(true)]
    public Color ForeColor { get; set; }
}

这是我的自定义控件：

public partial class myControl : Control
{
    private TextComponent tc = new TextComponent();

    protected override void OnPaint(PaintEventArgs pe)
    {
        pe.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

        GraphicsPath gp = new GraphicsPath();
        Rectangle rect = new Rectangle(1, 1, DisplayRectangle.Width - 3, DisplayRectangle.Height - 3);
        gp.AddRectangle(rect);
        pe.Graphics.FillPath(new SolidBrush(Color.LightCoral), gp);

        using (StringFormat sf = new StringFormat())
        {
            sf.Alignment = StringAlignment.Center;
            sf.LineAlignment = StringAlignment.Center;

            pe.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
            pe.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;
            pe.Graphics.DrawString(tc.Text, tc.Font, new SolidBrush(tc.ForeColor), rect, sf);
        }

        base.OnPaint(pe);
    }

    [Description("The Text Component for the Control"), Category("Text"), NotifyParentPropertyAttribute(true), DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public TextComponent TextComponent { get { return tc; } }

    public myControl()
    {
        this.DoubleBuffered = true;
        this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
        this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
        this.SetStyle(ControlStyles.ResizeRedraw, true);
        this.SetStyle(ControlStyles.Selectable, true);
    }

    [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
    public new string Text { get { return string.Empty; } }
}

Answer 1

尝试侦听PropertyChanged事件以使其工作。您必须将INotifyPropertyChanged接口添加到您的类并启动它：

[TypeConverter(typeof(ExpandableObjectConverter))]
public class TextComponent : INotifyPropertyChanged  {

  public event PropertyChangedEventHandler PropertyChanged;

  protected void OnChanged(string propertyName) {
    if (PropertyChanged != null) {
      PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
  }

  private string text = string.Empty;

  [NotifyParentProperty(true)]
  public string Text {
    get { return text; }
    set {
      text = value;
      OnChanged("Text");
    }
  }
}

然后在您的控制类中，监听事件并使控件无效：

public myControl() {
  this.DoubleBuffered = true;
  this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
  this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
  this.SetStyle(ControlStyles.ResizeRedraw, true);
  this.SetStyle(ControlStyles.Selectable, true);

  this.TextComponent.PropertyChanged += TextComponent_PropertyChanged;
}

void TextComponent_PropertyChanged(object sender, PropertyChangedEventArgs e) {
  this.Invalidate();
}

使用自定义类属性的Winforms控件不刷新

1 个答案: