public SafeHandleDC GetHdc()
{
if (this.bufHdc == null)
{
if (this.tempHdc != null)
{
return(this.tempHdc);
}
var handle = IntPtr.Zero;
using (var graphics = Graphics.FromHwnd(Handle))
{
var hdc = graphics.GetHdc();
handle = SafeNativeMethods.CreateCompatibleDC(hdc);
graphics.ReleaseHdc();
}
this.SetDefaultPaintState(handle);
return(this.tempHdc = new SafeHandleDC(handle));
}
return(this.bufHdc);
}
private void DisposeBuffer()
{
if (this.bufHBitmap != null)
{
this.bufHBitmap.Dispose();
this.bufHBitmap = null;
}
if (this.bufHdc != null)
{
this.bufHdc.Dispose();
this.bufHdc = null;
}
if (this.tempHdc != null)
{
this.tempHdc.Dispose();
this.tempHdc = null;
}
if (this.hFont != null)
{
this.hFont.Dispose();
this.hFont = null;
}
}
public void ReleaseHdc()
{
if (this.tempHdc != null)
{
this.tempHdc.Dispose();
this.tempHdc = null;
}
}
protected override void OnPaint(PaintEventArgs e)
{
this.EnsureSelectionArrays(this.CurrentTextColumnIndex);
#region buf
if (this.bufHBitmap != null)
{
if (this.bufHBitmapSize.Width != Width || this.bufHBitmapSize.Height != Height)
{
this.DisposeBuffer();
}
}
var destHdc = e.Graphics.GetHdc();
if (this.bufHdc == null || this.bufHdc.IsInvalid)
{
this.bufHdc = new SafeHandleDC(SafeNativeMethods.CreateCompatibleDC(destHdc));
}
if (this.bufHBitmap == null || this.bufHBitmap.IsInvalid)
{
var width = Width;
var height = Height;
if (width <= 0 || height <= 0)
{
e.Graphics.ReleaseHdc(destHdc);
return;
}
this.bufHBitmap = new SafeHandleGDI(SafeNativeMethods.CreateCompatibleBitmap(destHdc, width, height));
this.bufHBitmapSize = new Size(width, height);
SafeNativeMethods.SelectObject(this.bufHdc.DangerousGetHandle(), this.bufHBitmap.DangerousGetHandle());
}
#endregion
#region Initialize GDI resources
if (this.backBrush == null)
{
var c = this.BackColor;
this.backBrush = new SafeHandleGDI(SafeNativeMethods.CreateSolidBrush(ColorTranslator.ToWin32(c)));
c = Color.FromArgb((byte)(255 - SystemColors.Highlight.R), (byte)(255 - SystemColors.Highlight.G), (byte)(255 - SystemColors.Highlight.B));
this.caretBrushSelection = new SafeHandleGDI(SafeNativeMethods.CreateSolidBrush(ColorTranslator.ToWin32(c)));
}
#endregion
var hdc = this.bufHdc;
this.SetDefaultPaintState(hdc.DangerousGetHandle());
var clientRect = new RECT
{
right = ClientRectangle.Width,
bottom = ClientRectangle.Height
};
if (BackgroundImage != null)
{
if (staticBackgroundHBitmap == null)
{
staticBackgroundHBitmap = new SafeHandleGDI((BackgroundImage as Bitmap).GetHbitmap());
}
var bkgHdc = SafeNativeMethods.CreateCompatibleDC(destHdc);
var bkgHdcPrev = SafeNativeMethods.SelectObject(bkgHdc, staticBackgroundHBitmap.DangerousGetHandle());
for (var imgX = 0; imgX < ClientSize.Width; imgX += BackgroundImage.Width)
{
for (var imgY = 0; imgY < ClientSize.Height; imgY += BackgroundImage.Height)
{
SafeNativeMethods.BitBlt(hdc.DangerousGetHandle(), imgX, imgY, BackgroundImage.Width, BackgroundImage.Height, bkgHdc, 0, 0, NativeConstants.SRCCOPY);
}
}
SafeNativeMethods.SelectObject(bkgHdc, bkgHdcPrev);
SafeNativeMethods.DeleteDC(bkgHdc);
}
else
{
SafeNativeMethods.FillRect(hdc.DangerousGetHandle(), ref clientRect, this.backBrush.DangerousGetHandle());
}
#region Paint overlay under text if the control is read-only
if (this.IsReadOnly)
{
using (var g = Graphics.FromHdc(hdc.DangerousGetHandle()))
{
using (var hatchBrush = new HatchBrush(HatchStyle.ForwardDiagonal, Color.FromArgb(50, Color.Gray), Color.Transparent))
{
g.FillRectangle(hatchBrush, 0, 0, Width, Height);
}
}
}
#endregion
this._renderer.Render(hdc.DangerousGetHandle(), this.ScrollHost.ScrollPosH + this.GetTextRectangle(false).Left, this.ScrollHost.ScrollPosVIntegral, ClientSize);
#region Paint overlay if control is not enabled or virtual
if (Enabled == false)
{
using (var g = Graphics.FromHdc(hdc.DangerousGetHandle()))
{
using (var hatchBrush = new HatchBrush(HatchStyle.BackwardDiagonal, Color.Gray, Color.Transparent))
{
g.FillRectangle(hatchBrush, 0, 0, Width, Height);
}
}
}
else if (this.IsVirtual)
{
this.SetDefaultPaintState(hdc.DangerousGetHandle());
var brush = SafeNativeMethods.CreateHatchBrush(NativeConstants.HS_FDIAGONAL, ColorTranslator.ToWin32(Color.Gray));
var previousBrush = SafeNativeMethods.SelectObject(hdc.DangerousGetHandle(), brush);
var leftsideFillRect = new RECT
{
bottom = Height,
right = Padding.Left
};
SafeNativeMethods.FillRect(hdc.DangerousGetHandle(), ref leftsideFillRect, brush);
SafeNativeMethods.SelectObject(hdc.DangerousGetHandle(), previousBrush);
SafeNativeMethods.DeleteObject(brush);
}
#endregion
#region Paint caret
if (this._imeComposition != null && this._imeComposition.IsCompositioning)
{
this._imeComposition.Paint(hdc.DangerousGetHandle(), this.Caret.Location.X, this.Caret.Location.Y, this.Caret);
}
else
{
this.Caret.Render(hdc.DangerousGetHandle());
}
#endregion
#region Paint text limitation guides (when scrolling outside)
if (this.CanScrollOutside)
{
if (this.ScrollHost != null)
{
var endY = this.ScrollHost.VerticalMax - this.ScrollHost.ScrollPosVIntegral - this.LineHeight;
if (endY + this.LineHeight < ClientRectangle.Height)
{
// TODO: Should not be gray. Should be ControlPaint.Light(255 - this.BackColor)
var penHandle = SafeNativeMethods.CreatePen(NativeConstants.PS_DOT, -1, ColorTranslator.ToWin32(Color.Gray));
var previous = SafeNativeMethods.SelectObject(hdc.DangerousGetHandle(), penHandle);
SafeNativeMethods.MoveToEx(hdc.DangerousGetHandle(), 0, endY, IntPtr.Zero);
SafeNativeMethods.LineTo(hdc.DangerousGetHandle(), ClientRectangle.Width, endY);
SafeNativeMethods.SelectObject(hdc.DangerousGetHandle(), previous);
SafeNativeMethods.DeleteObject(penHandle);
}
var endX = this.ScrollHost.HorizontalMax - this.ScrollHost.ScrollPosH + Padding.Left + Padding.Right;
if (endX + this.LineHeight < ClientRectangle.Width)
{
var penHandle = SafeNativeMethods.CreatePen(NativeConstants.PS_DOT, -1,
ColorTranslator.ToWin32(Color.Gray));
var previous = SafeNativeMethods.SelectObject(hdc.DangerousGetHandle(), penHandle);
SafeNativeMethods.MoveToEx(hdc.DangerousGetHandle(), endX, 0, IntPtr.Zero);
SafeNativeMethods.LineTo(hdc.DangerousGetHandle(), endX, endY == -1
? ClientRectangle.Height
: endY);
SafeNativeMethods.SelectObject(hdc.DangerousGetHandle(), previous);
SafeNativeMethods.DeleteObject(penHandle);
}
}
}
#endregion
SafeNativeMethods.BitBlt(destHdc, 0, 0, this.bufHBitmapSize.Width, this.bufHBitmapSize.Height, hdc.DangerousGetHandle(), 0, 0, (int)NativeConstants.SRCCOPY);
e.Graphics.ReleaseHdc(destHdc);
destHdc = IntPtr.Zero;
base.OnPaint(e);
}
