Develop Reference

how to show name box in listview title view after using drawitem?

As you know there is no simple way for changing selected item back color in listview control and for that you should use drawItem event.
(Am I right or there is a way which I do not know?)
so, I use drawitem and try to make everything normal, except this property. it's good but in title view there is a small box after icon that show item name( also in large icon view),it's invisible but when I click on its location it shows. How should I make it visible always? thanks.
I added code and image,tanks for your response
void FileList_DrawItem(object sender, DrawListViewItemEventArgs e)
{
if (e.Item.Selected)
{
Rectangle rectangle = e.Bounds;
rectangle.Inflate(-1, -1);
Image image;
if (this.View == System.Windows.Forms.View.LargeIcon || this.View == System.Windows.Forms.View.Tile)
{
image = LargeImageList.Images[e.Item.ImageKey];
}
else
{
image = SmallImageList.Images[e.Item.ImageKey];
}
Rectangle rectPoint = new Rectangle(e.Item.Bounds.X + 3, e.Item.Bounds.Y + 3, image.Width - 3, image.Height - 3);
Rectangle srcRect = new Rectangle(0, 0, image.Width, image.Height);
using (Graphics g = e.Graphics)
{
g.DrawRectangle(Pens.Red, rectangle);
g.DrawImage(image, rectPoint, srcRect, GraphicsUnit.Pixel);
Rectangle rectangle2 =new Rectangle(e.Item.Bounds.X+image.Width+5,e.Item.Bounds.Y+(image.Height/2)+7,50,15);
using (StringFormat sf = new StringFormat())
{
using (Font headerFont =
new Font("Helvetica", 8, FontStyle.Regular))
{
e.Graphics.DrawString("Folder", headerFont,
Brushes.Black, rectangle2, sf);
}
}
}
}
else
{
e.DrawDefault = true;
}
}

I done it somehow, first maybe you need to set each item text to string.Empty or something like that, then you should change rectangle for text yourself. it is not very good but it can be done in no time. for each view change and test until it be good.

Crop image out of two points (C#)

Update:
Updated code added.
However for some reason it still doesn't work properly. If the coordinates are Bitmap coordinates, what could be the reason? The first code sample I put here doesn't work properly and the second gives me an OutOfMemoryException.
I've ran into a problem trying to crop an image between two points. In my project I have a pictureBox (named AP), and the general idea is that the user clicks on two points and the program crops the image between these two corners. I've tried two methods, one with Bitmap.Crop and the other one with Graphics.DrawImage, but both seemed to fail for the same reason and didn't work at all (cropped a much smaller portion of the image).
Code:
private void AP_Click(object sender, EventArgs e)
{
// Setting the corners
else if (mark_shape == 0)
{
var mouseEventArgs = e as MouseEventArgs;
if (picture_corners_set == 0)
{
northEast = AP.PointToClient(new Point(mouseEventArgs.X, mouseEventArgs.Y));
picture_corners_set = 1;
}
else if (picture_corners_set == 1)
{
southWest = AP.PointToClient(new Point(mouseEventArgs.X, mouseEventArgs.Y));
Rectangle imageRectangle = new Rectangle(southWest.X, northEast.Y, (northEast.X - southWest.X), (southWest.Y - northEast.Y));
var bmp = new Bitmap(imageRectangle.Width, imageRectangle.Height);
using (var gr = Graphics.FromImage(bmp))
{
gr.DrawImage(AP.Image, 0, 0, imageRectangle, GraphicsUnit.Pixel);
}
AP.Image = bmp;
enableAllButtons();
}
}
}

Since your cropped Bitmap image size is the same as the width/height of the user selection, I'm guessing you want that cropped image to be in the top/left of the new Bitmap and fill it. As it is, you're telling the DrawImage() method to draw that portion of the Bitmap in the same location, albeit in a smaller size Bitmap.
The correct way to do this is to draw the source rectangle image at (0, 0):
private Point pt1, pt2;
private void AP_Click(object sender, EventArgs e)
{
// ... obviously other code here ...
else if (mark_shape == 0) // Setting the corners
{
Point pt = AP.PointToClient(Cursor.Position);
if (picture_corners_set == 0)
{
pt1 = new Point(pt.X, pt.Y);
picture_corners_set = 1;
}
else if (picture_corners_set == 1)
{
pt2 = new Point(pt.X, pt.Y);
picture_corners_set = 0;
Rectangle imageRectangle = new Rectangle(new Point(Math.Min(pt1.X, pt2.X), Math.Min(pt1.Y, pt2.Y)), new Size(Math.Abs(pt2.X - pt1.X) + 1, Math.Abs(pt2.Y - pt1.Y) + 1));
var bmp = new Bitmap(imageRectangle.Width, imageRectangle.Height);
using (var gr = Graphics.FromImage(bmp))
{
gr.DrawImage(AP.Image, 0, 0, imageRectangle, GraphicsUnit.Pixel);
}
AP.Image = bmp;
enableAllButtons();
}
}
}
There are several other overloads you could use to do this, but the one above makes it pretty clear that imageRectangle is being drawn at (0, 0).

How to paint over a bitmap with a brush - C#/.NET

This seems like it should be simple, but I can't seem to find any way to do it. I have a custom WinForms control that has an overridden paint method that does some custom drawing.
I have a Bitmap in memory, and all I want to do is paint over the whole thing with a HashBrush, but preserve the alpha channel, so that the transparent parts of the bitmap don't get painted.
The bitmap in memory is not a simple shape, so it will not be feasible to define it as a set of paths or anything.
EDIT: In response to showing the code, there is a lot of code in the paint routine, so I'm only including a relevant snippet, which is the method in question. This method gets called from the main paint override. It accepts a list of images which are black transparency masks and combines them into one, then it uses a ColorMatrix to change the color of the combined image it created, allowing it to be overlayed on top of the background. All I want to accomplish is being able to also paint hashmarks on top of it.
private void PaintSurface(PaintEventArgs e, Image imgParent, List<Image> surfImgs, Rectangle destRect, ToothSurfaceMaterial material)
{
using (Bitmap bmp = new Bitmap(imgParent.Width, imgParent.Height,
System.Drawing.Imaging.PixelFormat.Format32bppPArgb))
{
using (Graphics g = Graphics.FromImage(bmp))
{
foreach (Image img in surfImgs)
{
g.DrawImage(img, System.Drawing.Point.Empty);
}
}
ColorMatrix matrix = new ColorMatrix(
new float[][] {
new float[] { 0, 0, 0, 0, 0},
new float[] { 0, 0, 0, 0, 0},
new float[] { 0, 0, 0, 0, 0},
new float[] { 0, 0, 0, 0.7f, 0},
new float[] { material.R / 255.0f,
material.G / 255.0f,
material.B / 255.0f,
0, 1}
});
ImageAttributes imageAttr = new ImageAttributes();
imageAttr.SetColorMatrix(matrix);
Rectangle r = GetSizedRect(imgParent, destRect);
e.Graphics.DrawImage(bmp,
r,
0,
0,
bmp.Width,
bmp.Height,
GraphicsUnit.Pixel, imageAttr);
}
}

The solution I ended up using was the following method. First I combine the individual masks into one, then create a new Bitmap and paint the whole thing with the HatchBrush, finally iterate through the mask and set the alpha values on the newly generated bitmap based on the mask.
private Bitmap GenerateSurface(Image imgParent, List<Image> surfImgs, ToothSurfaceMaterial material)
{
Bitmap mask = new Bitmap(imgParent.Width, imgParent.Height,
System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
using (Graphics g = Graphics.FromImage(mask))
{
foreach (Image img in surfImgs)
{
g.DrawImage(img, System.Drawing.Point.Empty);
}
}
Bitmap output = new Bitmap(mask.Width, mask.Height,
System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
using (Graphics g = Graphics.FromImage(output))
{
if (material.HatchStyle != null)
{
HatchBrush hb = new HatchBrush((HatchStyle)material.HatchStyle, material.FgColor, material.BgColor);
g.FillRectangle(hb, new Rectangle(0, 0, output.Width, output.Height));
}
else
{
SolidBrush sb = new SolidBrush(material.FgColor);
g.FillRectangle(sb, new Rectangle(0, 0, output.Width, output.Height));
}
}
var rect = new Rectangle(0, 0, output.Width, output.Height);
var bitsMask = mask.LockBits(rect, ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
var bitsOutput = output.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
unsafe
{
int offset = 0;
for (int y = 0; y < mask.Height; y++)
{
byte* ptrMask = (byte*)bitsMask.Scan0 + y * bitsMask.Stride;
byte* ptrOutput = (byte*)bitsOutput.Scan0 + y * bitsOutput.Stride;
for (int x = 0; x < mask.Width; x++)
{
offset = 4 * x + 3;
ptrOutput[offset] = (byte)(ptrMask[offset] * 0.7);
}
}
}
mask.UnlockBits(bitsMask);
output.UnlockBits(bitsOutput);
return output;
}

I think you don't need any ColorMatrix which is overkill, you just need a ColorMap, here is the code which may not suit your requirement but should give you the idea. That's because I possibly don't understand your problem well, if you have any problem, just leave some comment and I'll try to improve the answer:
ImageAttributes imgA = new ImageAttributes();
ColorMap cm = new ColorMap();
cm.OldColor = Color.Black
cm.NewColor = Color.FromArgb((byte)(0.7*255), Color.Green);
imgA.SetRemapTable(new ColorMap[] {cm });
GraphicsUnit gu = GraphicsUnit.Pixel;
g.DrawImage(imageToDraw,new Point[]{Point.Empty,
new Point(backImage.Width/2,0),
new Point(0,backImage.Height/2)},
Rectangle.Round(imageToDraw.GetBounds(ref gu)),
GraphicsUnit.Pixel, imgA);
the new Point[] is an array of 3 Points used to locate the destination Rectangle.
The code above is used to Draw the imageToDraw on top of the backImage and convert and color of Black to the color Green with Opacity = 70%. That's what you want to fulfill your code.
UPDATE
This may be what you want, in fact your code doesn't show what you want, it just shows what you have which doesn't implement anything related to your problem now. I deduce this from your very first description in your question. The input is an image with background color (which will be made partially transparent later) being Black. Now the output you want is an image with all the non-Black region being painted with a HatchBrush. This output will then be processed to turn the Black background to a partially transparent background.
public void PaintHatchBrush(Bitmap input, HatchBrush brush){
using(Graphics g = Graphics.FromImage(input)){
g.Clip = GetForegroundRegion(input, Color.Black);
GraphicsUnit gu = GraphicsUnit.Pixel;
g.FillRectangle(brush, input.GetBounds(ref gu));
}
}
//This is implemented using `GetPixel` which is not fast, but it gives you the idea.
public Region GetForegroundRegion(Bitmap input, Color backColor){
GraphicsPath gp = new GraphicsPath();
Rectangle rect = Rectangle.Empty;
bool jumpedIn = false;
for (int i = 0; i < bm.Height; i++) {
for (int j = 0; j < bm.Width; j++) {
Color c = bm.GetPixel(j, i);
if (c != backColor&&!jumpedIn) {
rect = new Rectangle(j, i, 1, 1);
jumpedIn = true;
}
if (jumpedIn && (c == backColor || j == bm.Width - 1)) {
rect.Width = j - rect.Left;
gp.AddRectangle(rect);
jumpedIn = false;
}
}
}
return new Region(gp);
}
//Usage
HatchBrush brush = new HatchBrush(HatchStyle.Percent30, Color.Green, Color.Yellow);
PaintHatchBrush(yourImage, brush);
//then yourImage will have HatchBrush painted on the surface leaving the Black background intact.
//This image will be used in the next process to turn the Black background into 70%
//opacity background as you did using ColorMatrix (or more simply using ColorMap as I posted previously)

CSS3-like box shadow implementation / algorithm

I am looking for or trying to implement an algorithm to draw box shadows (as in the CSS 3 specifiction) which accepts the following parameters:
Horizontal Offset
Vertical Offset
Inset
Spread
Blur
Color
(Optional: Opacity).
Where to start.
I have looked for Firefox / Chrome source code to see if I can pull an implementation from there, no such luck!
I have looked into linear gradient algorithms, drawing them with a box, which kind of works, except with rounded rectangles it leaves empty pixels in the shadow, presumably due to the radius of the edge.
I am doing this in .NET with GDI+. My aim is NOT to create drop shadows for images. I have already seen articles on this. I want to create drop shadows for shapes drawn with GDI+.
Any help appreciated!

I coded for you a DropShadowPanel that handles controls inside it and adds the shadows (outer or inner) as required by the Tag of the control.
As you can see in the image controls get their shadows as defined:
tags:
textbox: DropShadow:5,5,5,10,#000000,noinset
calendar: DropShadow:10,10,80,30,#0000FF,noinset
picturebox top left: DropShadow:-50,20,50,10,#888888,noinset
picturebox bottom left: DropShadow:10,10,20,20,#442200,inset
picturebox lower right: DropShadow:0,0,50,50,#442200,noinset
Here is the code for the Panel:
(it uses intermediate drawings into an image before drawing to the control gdi object, to not make the form crawl - this actually works pretty fast)
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication4
{
public class DropShadowPanel : Panel
{
protected override void OnControlAdded(ControlEventArgs e)
{
e.Control.Paint += new PaintEventHandler(Control_Paint);
base.OnControlAdded(e);
}
void Control_Paint(object sender, PaintEventArgs e)
{
CheckDrawInnerShadow(sender as Control, e.Graphics);
}
private void CheckDrawInnerShadow(Control sender, Graphics g)
{
var dropShadowStruct = GetDropShadowStruct(sender);
if (dropShadowStruct == null || !dropShadowStruct.Inset)
{
return;
}
DrawInsetShadow(sender as Control, g);
}
protected override void OnControlRemoved(ControlEventArgs e)
{
e.Control.Paint -= new PaintEventHandler(Control_Paint);
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
DrawShadow(Controls.OfType<Control>().Where(c => c.Tag != null && c.Tag.ToString().StartsWith("DropShadow")), e.Graphics);
}
void DrawInsetShadow(Control control, Graphics g)
{
var dropShadowStruct = GetDropShadowStruct(control);
var rInner = new Rectangle(Point.Empty, control.Size);
var img = new Bitmap(rInner.Width, rInner.Height, g);
var g2 = Graphics.FromImage(img);
g2.CompositingMode = CompositingMode.SourceCopy;
g2.FillRectangle(new SolidBrush(dropShadowStruct.Color), 0, 0, control.Width, control.Height);
rInner.Offset(dropShadowStruct.HShadow, dropShadowStruct.VShadow);
rInner.Inflate(dropShadowStruct.Blur, dropShadowStruct.Blur);
rInner.Inflate(-dropShadowStruct.Spread, -dropShadowStruct.Spread);
double blurSize = dropShadowStruct.Blur;
double blurStartSize = blurSize;
do
{
var transparency = blurSize/blurStartSize;
var color = Color.FromArgb(((int)(255 * (transparency * transparency))), dropShadowStruct.Color);
rInner.Inflate(-1,-1);
DrawRoundedRectangle(g2, rInner, (int)blurSize, Pens.Transparent, color);
blurSize--;
} while (blurSize > 0);
g.DrawImage(img, 0, 0);
g.Flush();
g2.Dispose();
img.Dispose();
}
void DrawShadow(IEnumerable<Control> controls, Graphics g)
{
foreach (var control in controls)
{
var dropShadowStruct = GetDropShadowStruct(control);
if (dropShadowStruct.Inset)
{
continue; // must be handled by the control itself
}
DrawOutsetShadow(g, dropShadowStruct, control);
}
}
// drawing the loop on an image because of speed
private void DrawOutsetShadow(Graphics g, dynamic dropShadowStruct, Control control)
{
var rOuter = control.Bounds;
var rInner = control.Bounds;
rInner.Offset(dropShadowStruct.HShadow, dropShadowStruct.VShadow);
rInner.Inflate(-dropShadowStruct.Blur, -dropShadowStruct.Blur);
rOuter.Inflate(dropShadowStruct.Spread, dropShadowStruct.Spread);
rOuter.Offset(dropShadowStruct.HShadow, dropShadowStruct.VShadow);
var originalOuter = rOuter;
var img = new Bitmap(originalOuter.Width, originalOuter.Height, g);
var g2 = Graphics.FromImage(img);
var currentBlur = 0;
do
{
var transparency = (rOuter.Height - rInner.Height)/(double) (dropShadowStruct.Blur*2 + dropShadowStruct.Spread*2);
var color = Color.FromArgb(((int)(255 * (transparency * transparency))), dropShadowStruct.Color);
var rOutput = rInner;
rOutput.Offset(-originalOuter.Left, -originalOuter.Top);
DrawRoundedRectangle(g2, rOutput, currentBlur, Pens.Transparent, color);
rInner.Inflate(1, 1);
currentBlur = (int) ((double) dropShadowStruct.Blur*(1 - (transparency*transparency)));
} while (rOuter.Contains(rInner));
g2.Flush();
g2.Dispose();
g.DrawImage(img, originalOuter);
img.Dispose();
}
private static dynamic GetDropShadowStruct(Control control)
{
if (control.Tag == null || !(control.Tag is string) || !control.Tag.ToString().StartsWith("DropShadow"))
return null;
string[] dropShadowParams = control.Tag.ToString().Split(':')[1].Split(',');
var dropShadowStruct = new
{
HShadow = Convert.ToInt32(dropShadowParams[0]),
VShadow = Convert.ToInt32(dropShadowParams[1]),
Blur = Convert.ToInt32(dropShadowParams[2]),
Spread = Convert.ToInt32(dropShadowParams[3]),
Color = ColorTranslator.FromHtml(dropShadowParams[4]),
Inset = dropShadowParams[5].ToLowerInvariant() == "inset"
};
return dropShadowStruct;
}
private void DrawRoundedRectangle(Graphics gfx, Rectangle bounds, int cornerRadius, Pen drawPen, Color fillColor)
{
int strokeOffset = Convert.ToInt32(Math.Ceiling(drawPen.Width));
bounds = Rectangle.Inflate(bounds, -strokeOffset, -strokeOffset);
var gfxPath = new GraphicsPath();
if (cornerRadius > 0)
{
gfxPath.AddArc(bounds.X, bounds.Y, cornerRadius, cornerRadius, 180, 90);
gfxPath.AddArc(bounds.X + bounds.Width - cornerRadius, bounds.Y, cornerRadius, cornerRadius, 270, 90);
gfxPath.AddArc(bounds.X + bounds.Width - cornerRadius, bounds.Y + bounds.Height - cornerRadius, cornerRadius,
cornerRadius, 0, 90);
gfxPath.AddArc(bounds.X, bounds.Y + bounds.Height - cornerRadius, cornerRadius, cornerRadius, 90, 90);
}
else
{
gfxPath.AddRectangle(bounds);
}
gfxPath.CloseAllFigures();
gfx.FillPath(new SolidBrush(fillColor), gfxPath);
if (drawPen != Pens.Transparent)
{
var pen = new Pen(drawPen.Color);
pen.EndCap = pen.StartCap = LineCap.Round;
gfx.DrawPath(pen, gfxPath);
}
}
}
}
Code is written fast without much review so there may be bugs especially if you set wring tags on controls).
PS. You may notice that inner shadow does not work for some controls. This is because they are wrappers around windows system controls. The panel cannot overcome this by itself, but you may do it like here: http://www.codeproject.com/Articles/4548/Generating-missing-Paint-event-for-TreeView-and-Li

Align text vertically with VisualStyleRenderer for VisualStyleElement.ToolTip.Standard.Normal

I'm creating a custom ToolTip that will bold the first line of text if the text is multi-line. I'm also using the VisualStyleRenderer to draw the tool tip correctly with styles. However, when I draw the text (even with TextFormatFlags.VerticalCenter set), it draws at the top of the box. I was going to just bump the bounding box down 2 pixels (which fixed it on Windows 7) but I wasn't 100% sure how portable that would be to another OS. Does anyone know how to draw the text vertically centered correctly?
EDIT: To make this clear, I know this code doesn't bold the first line. I'm trying to first replicate a standard tooltip, and then afterwards do the bolding.
public class BoldedFirstLineToolTip : ToolTip
{
public BoldedFirstLineToolTip()
{
this.OwnerDraw = true;
this.Draw += new DrawToolTipEventHandler(OnDraw);
}
private void OnDraw(object sender, DrawToolTipEventArgs e)
{
// Try to draw using the visual style renderer.
if (VisualStyleRenderer.IsElementDefined(VisualStyleElement.ToolTip.Standard.Normal))
{
var renderer = new VisualStyleRenderer(VisualStyleElement.ToolTip.Standard.Normal);
renderer.DrawBackground(e.Graphics, e.Bounds);
var b = e.Bounds;
// b.Y + 2 // This works when using e.Graphics.DrawString.
renderer.DrawText(e.Graphics, b, e.ToolTipText, false /*drawDisabled*/,
TextFormatFlags.HorizontalCenter | TextFormatFlags.VerticalCenter);
}
else
{
// Fall back to non-visual style drawing.
e.DrawBackground();
e.DrawBorder();
e.DrawText();
}
}
}

I've decided to just use padding fixes. I've provided my full solution below. I tested on both XP and Windows 7.
public class BoldedFirstLineToolTip : ToolTip
{
public BoldedFirstLineToolTip()
{
this.OwnerDraw = true;
this.Draw += new DrawToolTipEventHandler(OnDraw);
}
private void OnDraw(object sender, DrawToolTipEventArgs e)
{
// Try to draw using the visual style renderer.
if (VisualStyleRenderer.IsSupported && VisualStyleRenderer.IsElementDefined(VisualStyleElement.ToolTip.Standard.Normal))
{
var bounds = e.Bounds;
var renderer = new VisualStyleRenderer(VisualStyleElement.ToolTip.Standard.Normal);
renderer.DrawBackground(e.Graphics, bounds);
var color = renderer.GetColor(ColorProperty.TextColor);
var text = e.ToolTipText;
using (var textBrush = new SolidBrush(renderer.GetColor(ColorProperty.TextColor)))
using (var font = e.Font)
{
// Fix the positioning of the bounds for the text rectangle.
var rendererBounds = new Rectangle(e.Bounds.X + 6, e.Bounds.Y + 2, e.Bounds.Width - 6 * 2, e.Bounds.Height - 2 * 2);
if (!text.Contains('\n'))
{
renderer.DrawText(e.Graphics, rendererBounds, text);
}
else
{
var lines = text.Split('\n').Select(l => l.Trim());
var first = lines.First();
var otherLines = Environment.NewLine + String.Join(Environment.NewLine, lines.Skip(1).ToArray());
// Draw the first line.
using (var boldFont = new Font(font, FontStyle.Bold))
{
e.Graphics.DrawString(first, boldFont, textBrush, rendererBounds.X - 1, rendererBounds.Y - 1);
}
renderer.DrawText(e.Graphics, rendererBounds, otherLines, false /*drawDisabled*/, TextFormatFlags.Left);
}
}
}
else
{
// Fall back to non-visual style drawing.
e.DrawBackground();
e.DrawBorder();
using (var sf = new StringFormat())
{
sf.LineAlignment = StringAlignment.Center;
e.Graphics.DrawString(e.ToolTipText, SystemFonts.DialogFont, Brushes.Black, e.Bounds, sf);
}
}
}
}