Question

我们有一个简单的用户控件，当我们在表单中使用它时工作正常，但是当我们尝试通过此方法将其托管到StatusStrip时，永远不会调用OnPaint事件。 MSDN文档声明这应该“正常”，但是我们什么也看不见，并确认OnPaint事件永远不会被调用。：

public partial class SimpleUserControl : UserControl
{
    public SimpleUserControl( )
    {
        InitializeComponent( );

        // Set the styles for drawing
        SetStyle(ControlStyles.AllPaintingInWmPaint |
            ControlStyles.ResizeRedraw |
            ControlStyles.DoubleBuffer |
            ControlStyles.SupportsTransparentBackColor,
            true);
    }

    [System.ComponentModel.EditorBrowsableAttribute( )]
    protected override void OnPaint( PaintEventArgs e )
    {
        Rectangle _rc = new Rectangle( 0, 0, this.Width, this.Height );
        e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        e.Graphics.DrawArc( new Pen( Color.Red ), _rc, 180, 180 );
    }

}

public Form1( )
{
    InitializeComponent( );

    SimpleUserControl suc = new SimpleUserControl( );
    suc.Size = new Size( 30, 20 );
    ToolStripControlHost tsch = new ToolStripControlHost( suc );
    statusStrip1.Items.Add(tsch);
}

Answer 1

ToolStripControlHost有一个奇怪的怪癖，它需要为它所托管的控件设置MinimumSize：

尝试添加此内容：

suc.Size = new Size(30, 20);
suc.MinimumSize = suc.Size;

Answer 2

我有同样的问题。我的解决方案是从ToolStripControlHost创建一个新类，并覆盖ToolStripItem.OnPaint方法，如下所示：

[System.ComponentModel.DesignerCategory("code")]
[ToolStripItemDesignerAvailability(ToolStripItemDesignerAvailability.All]
public class ToolStripSimpleUserControl : ToolStripControlHost
{
    public ToolStripSimpleUserControl ()
        : base(new SimpleUserControl())
    {
    }

    public SimpleUserControl StripSimpleUserControl
    {
        get { return Control as SimpleUserControl; }
    }


    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        // not thread safe!
        if (e != null)
        {
            this.StripSimpleUserControl.Invalidate();
        }
    }
}

在公共表单1（）

public Form1( )
{
     InitializeComponent( );

     ToolStripSimpleUserControl suc = new ToolStripSimpleUserControl( );
     suc.StripSimpleUserControl.Size = new Size( 30, 20 );

     statusStrip1.Items.Add(suc);
}

了解更多规则访问http://msdn.microsoft.com/en-us/library/9k5etstz.aspx

和访问http://tonyfear.netau.net/index.php?option=com_content&view=category&layout=blog&id=3&limitstart=5

托管UserControl的StatusStrip无法调用UserControls OnPaint事件

2 个答案: