【发布时间】：2017-09-06 20:31:10
【问题描述】：
我正在构建基于 ScrollableControl 的自定义用户控件。
现在我正在尝试在我的控件周围添加边框（类似于 DataGridView 的边框）
我可以使用以下方法绘制边框：
e.Graphics.TranslateTransform(AutoScrollPosition.X*-1, AutoScrollPosition.Y*-1);
ControlPaint.DrawBorder(e.Graphics, ClientRectangle, Color.DarkBlue, ButtonBorderStyle.Dashed);
但这会在 ClientRectangle 周围绘制边框，而不是在整个控件周围：
正如您在上图中看到的，边框不像 DataGridView 中那样围绕滚动条。
我可以在整个控件周围绘制边框，以便滚动条包含在边框包围的区域中吗？
编辑：
基于Textbox custom onPaint，我可以通过覆盖WndProc 来绘制自定义边框，但我得到了这个看起来很奇怪的边框闪烁：
这是我目前拥有的完整代码：
internal class TestControl : ScrollableControl
{
private int _tileWidth = 100;
private int _tileHeight = 100;
private int _tilesX = 20;
private int _tilesY = 20;
public TestControl()
{
SetStyle(ControlStyles.ResizeRedraw, true);
SetStyle(ControlStyles.UserPaint, true);
SetStyle(ControlStyles.AllPaintingInWmPaint, true);
SetStyle(ControlStyles.Opaque, true);
SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
UpdateStyles();
ResizeRedraw = true;
AutoScrollMinSize = new Size(_tilesX*_tileWidth, _tilesY*_tileHeight);
}
private bool _test = true;
[DefaultValue(true)]
public bool Test
{
get { return _test; }
set
{
if(_test==value) return;
_test = value;
Update();
}
}
[DllImport("user32")]
private static extern IntPtr GetWindowDC(IntPtr hwnd);
struct RECT
{
public int left, top, right, bottom;
}
struct NCCALSIZE_PARAMS
{
public RECT newWindow;
public RECT oldWindow;
public RECT clientWindow;
IntPtr windowPos;
}
int clientPadding = 1;
int actualBorderWidth = 1;
Color borderColor = Color.Black;
protected override void WndProc(ref Message m)
{
//We have to change the clientsize to make room for borders
//if not, the border is limited in how thick it is.
if (m.Msg == 0x83 && _test) //WM_NCCALCSIZE
{
if (m.WParam == IntPtr.Zero)
{
RECT rect = (RECT)Marshal.PtrToStructure(m.LParam, typeof(RECT));
rect.left += clientPadding;
rect.right -= clientPadding;
rect.top += clientPadding;
rect.bottom -= clientPadding;
Marshal.StructureToPtr(rect, m.LParam, false);
}
else
{
NCCALSIZE_PARAMS rects = (NCCALSIZE_PARAMS)Marshal.PtrToStructure(m.LParam, typeof(NCCALSIZE_PARAMS));
rects.newWindow.left += clientPadding;
rects.newWindow.right -= clientPadding;
rects.newWindow.top += clientPadding;
rects.newWindow.bottom -= clientPadding;
Marshal.StructureToPtr(rects, m.LParam, false);
}
}
if (m.Msg == 0x85 && _test) //WM_NCPAINT
{
base.WndProc(ref m);
IntPtr wDC = GetWindowDC(Handle);
using (Graphics g = Graphics.FromHdc(wDC))
{
ControlPaint.DrawBorder(g, new Rectangle(0, 0, Size.Width, Size.Height), borderColor, actualBorderWidth, ButtonBorderStyle.Solid,
borderColor, actualBorderWidth, ButtonBorderStyle.Solid, borderColor, actualBorderWidth, ButtonBorderStyle.Solid,
borderColor, actualBorderWidth, ButtonBorderStyle.Solid);
}
return;
}
base.WndProc(ref m);
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
e.Graphics.FillRectangle(new SolidBrush(BackColor), ClientRectangle);
e.Graphics.TranslateTransform(AutoScrollPosition.X, AutoScrollPosition.Y);
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
var offsetX = (AutoScrollPosition.X*-1)/_tileWidth;
var offsetY = (AutoScrollPosition.Y*-1)/_tileHeight;
var visibleX = Width/_tileWidth + 2;
var visibleY = Height/_tileHeight + 2;
var x = Math.Min(visibleX + offsetX, _tilesX);
var y = Math.Min(visibleY + offsetY, _tilesY);
for (var i = offsetX; i < x; i++)
{
for (var j = offsetY; j < y; j++)
{
e.Graphics.FillRectangle(Brushes.Beige, new Rectangle(i*_tileWidth, j*_tileHeight, _tileWidth, _tileHeight));
e.Graphics.DrawString(string.Format("{0}:{1}", i, j), Font, Brushes.Black, new Rectangle(i*_tileWidth, j*_tileHeight, _tileWidth, _tileHeight));
}
}
using (var p = new Pen(Color.Black))
{
for (var i = offsetX + 1; i < x; i++)
{
e.Graphics.DrawLine(p, i*_tileWidth, 0, i*_tileWidth, y*_tileHeight);
}
for (var i = offsetY + 1; i < y; i++)
{
e.Graphics.DrawLine(p, 0, i*_tileHeight, x*_tileWidth, i*_tileHeight);
}
}
e.Graphics.FillRectangle(Brushes.White, AutoScrollPosition.X*-1 + 10, AutoScrollPosition.Y*-1 + 10, 35, 14);
e.Graphics.DrawString("TEST", DefaultFont, new SolidBrush(Color.Red), AutoScrollPosition.X*-1 + 10, AutoScrollPosition.Y*-1 + 10);
e.Graphics.TranslateTransform(AutoScrollPosition.X*-1, AutoScrollPosition.Y*-1);
ControlPaint.DrawBorder(e.Graphics, ClientRectangle, Color.Red, actualBorderWidth, ButtonBorderStyle.None,
Color.Red, actualBorderWidth, ButtonBorderStyle.None, Color.Red, actualBorderWidth, ButtonBorderStyle.Solid,
Color.Red, actualBorderWidth, ButtonBorderStyle.Solid);
}
protected override void OnScroll(ScrollEventArgs e)
{
if (DesignMode)
{
base.OnScroll(e);
return;
}
if (e.Type == ScrollEventType.First)
{
LockWindowUpdate(Handle);
}
else
{
LockWindowUpdate(IntPtr.Zero);
Update();
if (e.Type != ScrollEventType.Last) LockWindowUpdate(Handle);
}
}
protected override void OnMouseWheel(MouseEventArgs e)
{
if (VScroll && (ModifierKeys & Keys.Shift) == Keys.Shift)
{
VScroll = false;
LockWindowUpdate(Handle);
base.OnMouseWheel(e);
LockWindowUpdate(IntPtr.Zero);
Update();
VScroll = true;
}
else
{
LockWindowUpdate(Handle);
base.OnMouseWheel(e);
LockWindowUpdate(IntPtr.Zero);
Update();
}
}
[DllImport("user32.dll", SetLastError = true)]
private static extern bool LockWindowUpdate(IntPtr hWnd);
}
这种闪烁可以解决吗？
【问题讨论】：
-
你写了
ControlPaint.DrawBorder(e.Graphics, ClientRectangle,..然后抱怨在ClientRectangle周围画了边框？？？ -
@TaW 我试过 this.Width 而不是 ClientRectangle.Width，但看起来滚动条是在顶部绘制的
-
UC 有 BorderStyle 吗？我建议单身..
-
@TaW 我使用
ScrollableControl作为基础，所以没有BorderStyle属性。我正在尝试手动绘制。 -
@TaW 我搜索了一下，因为我无法决定选择什么作为基类。我找到了这个答案：stackoverflow.com/a/1322499/965722 我认为
ScrollableControl将是一个不错的选择，因为我不想要任何额外的东西，我想尽可能获得最高性能，但我看到我正在尝试重新创建UserControl来自ScrollableControl
标签： c# .net winforms user-controls