I've come across several methods of applying gradient styles to objects in a windows form application. All the methods involve overriding the OnPaint method. However, I am looking the change the style at runtime based on validation.
How can I apply the new gradient style to an already rendered button (like I can with BackColor)?
R,
C.
UPDATE: This is the code I am currently using. It appears to have no effect
private void Button_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
Graphics g = e.Graphics;
g.DrawString("This is a diagonal line drawn on the control",
new Font("Arial", 10), System.Drawing.Brushes.Blue, new Point(30, 30));
g.DrawLine(System.Drawing.Pens.Red, btn.Left, btn.Top,
btn.Right, btn.Bottom);
this.btn.Invalidate();
}
Being called by
btn.Paint += new PaintEventHandler(this.Button_Paint);
FURTHER UPDATE WITH CURRENT CODE
private void Button_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.DrawString("This is a diagonal line drawn on the control",
new Font("Arial", 10), System.Drawing.Brushes.Blue, new Point(30, 30));
g.DrawLine(System.Drawing.Pens.Red, btn.Left, btn.Top,
btn.Right, btn.Bottom);
}
private void btn_Click(object sender, EventArgs e)
{
btn.Paint += new PaintEventHandler(this.Button_Paint);();
btn.Invalidate();
}
There are two parts to this. One, as SLaks said, you need to draw the gradient in your Paint event handler. This would look something like this (my example here is a bit messy for the sake of brevity):
private void Button_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
if (MyFormIsValid()) {
g.DrawString("This is a diagonal line drawn on the control",
new Font("Arial", 10), System.Drawing.Brushes.Blue, new Point(30, 30));
g.DrawLine(System.Drawing.Pens.Red, btn.Left, btn.Top,
btn.Right, btn.Bottom);
}
else {
g.FillRectangle(
new LinearGradientBrush(PointF.Empty, new PointF(0, btn.Height), Color.White, Color.Red),
new RectangleF(PointF.Empty, btn.Size));
}
}
Also, you need to do your validation and redraw the button when it is clicked:
btn.Click += Button_Click;
...
private void Button_Click(object sender, EventArgs e)
{
DoValidations();
btn.Invalidate();
}
Of course, you'll have to implement the DoValidations() and MyFormIsValid() methods.
Here's the whole thing as a runnable sample program: http://pastebin.com/cfXvtVwT
As you've seen, you need to handle the Paint event.
You can set a boolean in your class to indicate whether to draw the gradient or not.
Related
I created two Rectangles. I want to add events on them. For example when mouse hover on one, the hovered one will change color, can do resize or drag them(rectangles) to other place...
I was just wondering if I could control the drawn graphic, or it will like Microsoft Paint that after you painted, the object can not be operate unless you clear canvas and do redraw.
Is it possible to control a drawn graphic, thanks for any suggestion.
Simple code of my drawn graphics
private void Form1_Paint(object sender, PaintEventArgs e)
{
// Create pen.
Pen blackPen = new Pen(Color.Black, 3);
// Create rectangle.
Rectangle rect1 = new Rectangle(20, 20, 250, 250);
Rectangle rect2 = new Rectangle(70, 70, 150, 150);
// Draw rectangle to screen.
e.Graphics.FillRectangle(Brushes.DeepSkyBlue, rect1);
e.Graphics.FillRectangle(Brushes.LightBlue, rect2);
}
Also, you can create your own control like:
class RectangleControl : Control
{
public void FillRectangle(Color color)
{
this.BackColor = color;
}
}
Then :
private void Form1_Paint(object sender, PaintEventArgs e)
{
RectangleControl rect1 = new RectangleControl() { Parent = this, Left = 20, Top = 20, Width = 250, Height = 250 };
rect1.FillRectangle(Color.DeepSkyBlue);
RectangleControl rect2 = new RectangleControl() { Parent = rect1, Left = 50, Top = 50, Width = 150, Height = 150 };
rect2.FillRectangle(Color.LightBlue);
rect1.MouseHover += Rect1_MouseHover;
rect2.MouseLeave += Rect2_MouseLeave;
}
private void Rect2_MouseLeave(object sender, EventArgs e)
{
(sender as RectangleControl).BackColor = Color.Yellow;
}
private void Rect1_MouseHover(object sender, EventArgs e)
{
(sender as RectangleControl).BackColor = Color.LightBlue;
}
You can use Panel control instead.
Just add 2 panel controls as you would like them to be arranged and add 2 event handlers:
private void panel1_MouseHover(object sender, EventArgs e)
{
panel1.BackColor = Color.Yellow;
}
private void panel1_MouseLeave(object sender, EventArgs e)
{
panel1.BackColor = Color.LightBlue;
}
You can monitor the MouseMove.
Here's code using MouseMove and some brush values used by the rectangles.
using System.Drawing;
using System.Windows.Forms;
namespace Question_Answer_WinForms_App
{
public partial class Form1 : Form
{
public Brush outerRectangleBrush = Brushes.DeepSkyBlue;
public Brush innerRectangleBrush = Brushes.LightBlue;
public Form1()
{
InitializeComponent();
Paint += Form1_Paint;
MouseMove += Form1_MouseMove;
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
var isWithinOuterRectangle = e.Location.X >= 20
&& e.Location.X <= 250 + 20
&& e.Location.Y >= 20
&& e.Location.Y <= 250 + 20;
var isWithinInnerRectangle = e.Location.X >= 70
&& e.Location.X <= 150 + 70
&& e.Location.Y >= 70
&& e.Location.Y <= 150 + 70;
if (isWithinOuterRectangle)
{
if (isWithinInnerRectangle)
{
outerRectangleBrush = Brushes.DeepSkyBlue;
innerRectangleBrush = Brushes.Red;
Refresh();
}
else
{
outerRectangleBrush = Brushes.Red;
innerRectangleBrush = Brushes.LightBlue;
Refresh();
}
}
else
{
outerRectangleBrush = Brushes.DeepSkyBlue;
innerRectangleBrush = Brushes.LightBlue;
Refresh();
}
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
// Create pen.
Pen blackPen = new Pen(Color.Black, 3);
// Create rectangle.
Rectangle rect1 = new Rectangle(20, 20, 250, 250);
Rectangle rect2 = new Rectangle(70, 70, 150, 150);
// Draw rectangle to screen.
e.Graphics.FillRectangle(outerRectangleBrush, rect1);
e.Graphics.FillRectangle(innerRectangleBrush, rect2);
}
}
}
#FJF, writing a ms-paint like application is not a complicated task. Windows Forms applications are using GDI+ to render graphics. so you can write a simple paint application using WindowsForms.
#nexolini uses a panel to do some draws. actually Ms-Paint does the same somehow. Ms-Paint is a Single-Layer Editor. So you can't resize all objects anytime you wanted (but as I said before you can assume that you have a panel for each newly drawn Shapes; Something like what Ms-Paint does).
So what is the problem?
Ms-Paint doesn't tracks your mouse movements and it doesn't needed (as it's a single layer). You can do all of it's tasks using these Answers.
e.g: for adding a Fill Color tool you can use a getpixel and putpixel to do a recursive algorithm on you image. and you are not needed to know which shape you are working on.
all the other tasks could be implemented easy.
for multi-layer Editors I will prefer to use a more powerful framework (but it's also could be implemented in Windows forms in a bad way), Like WPF. WPF uses DirectX to render your graphics and you are able to write an smooth Editor. WPF is designed to handle your graphical request so it does better on graphics.
#Reza_Aghaei 's comments are useful for Windows Forms.
I'm currently working on windows form application where I have two forms; form1 and form2. There is a button inside form1 which opens form2 when clicked and what I want is to create a rectangle inside a panel of form1 when a button inside Form2 is clicked. I put some code to create rectangle inside the button click event of form2, but it showed nothing when clicked. However, whenever I put the draw.rectangle method inside the same form where button is clicked, it work, but differently it doesn't
Here's the code inside form1
private void btnSave_Click(object sender, EventArgs e)
{
Layoutsetting a = new Layoutsetting();
a.ShowDialog();
}
public void DrawObject()
{
Graphics g = panel1.CreateGraphics();
Rectangle rect = new Rectangle(10, 10, 80, 90);
rect.Inflate(-10, -10);
g.DrawRectangle(black, rect);
g.FillRectangle(Brushes.BlueViolet, rect);
StringFormat f = new StringFormat();
f.LineAlignment = StringAlignment.Center;
f.Alignment = StringAlignment.Center;
g.DrawString("Hello", this.Font, Brushes.GhostWhite, rect, f);
panel1.Refresh();
}
This is the code inside form2
private void btnConfirm_Click(object sender, EventArgs e)
{
Form1.Default.DrawObject();
this.Close();
}
The problem is not with drawing rectangle, the panel paint event fires whenever even a slightest part of the panel were hidden (for example a part of it was behind another form) and redraws the panel, so the rectangle disappears (but when it is the active form which paint event doesn't fire, the rectangle will be drawn and will not be cleared unless you do something that panel needs to be redrawn.).
Easy Solution:
Create an image of recangle and use it as background image when needed, instead of drawing it.
Another Solution:
add a property to your form (or your panel):
public bool NeedsToBeDrawn {get; set;}
instead of this line of code:
Form1.Default.DrawObject();
just set the property to true:
Form1.NeedsToBeDrawn = true;
and move your code to your panel's paint event:
private void panel1_Paint(object sender, PaintEventArgs e)
{
if(NeedsToBeDrawn)
{
Rectangle rect = new Rectangle(10, 10, 80, 90);
rect.Inflate(-10, -10);
e.Graphics.DrawRectangle(black, rect);
e.Graphics.FillRectangle(Brushes.BlueViolet, rect);
StringFormat f = new StringFormat();
f.LineAlignment = StringAlignment.Center;
f.Alignment = StringAlignment.Center;
e.Graphics.DrawString("Hello", this.Font, Brushes.GhostWhite, rect, f);
}
}
You have to add a method to Paint:
panel1.Paint += new System.Windows.Forms.PaintEventHandler(this.draw);
private void draw(object sender, PaintEventArgs e)
{
if(buttonClicked) {
Graphics g = e.Graphics;
//...
}
}
How to draw image on tabPage overlapping buttons
Black circles(DrawImage on tabPage8_Paint) should be above the buttons:
http://rghost.ru/6sVBl8mkh/image.png
It must be so:
http://rghost.ru/6BgDM77pq/image.png
My code
public SibModem() {
InitializeComponent();
tabPage8.Paint += new PaintEventHandler(tabPage8_Paint);
gettime();
this.SizeChanged += new EventHandler(this.SibModem_Resize);
}
protected void tabPage8_Paint(object sender, PaintEventArgs e) {
GraphicsUnit units = GraphicsUnit.Pixel;
base.OnPaint(e);
Graphics g = e.Graphics;
g.DrawImage(bg, 0, 0);
Rectangle srcRect = new Rectangle(offsetant, 0, w, h);
g.DrawImage(anten, x, y, srcRect, units);
Rectangle ussdwaitRect = new Rectangle(offsetussd, 0, 64, 64);
g.DrawImage(ussdwait, usx, usy, ussdwaitRect, units);
}
You can't draw above nested controls, so you need to draw parts of the image onto those Buttons.
So combine drawing onto the tabpage and drawing onto the buttons you need to adorn!
Here is a simple example using only one image:
A few class level variables:
Point iLoc = Point.Empty;
Image img = null;
List<Button> overlaidButtons = new List<Button>();
Prepare the image, its position and a list of possibly overlaid buttons:
public Form1()
{
InitializeComponent();
string imgN = #"d:\scrape\gears\gear_12x4hand.png";
img = Image.FromFile(imgN);
iLoc = new Point(100, 100);
overlaidButtons.AddRange(new []{button10,button11,button12,button13 });
// each button calls the same paint event
foreach (Button btn in overlaidButtons) btn.Paint += btn_Paint;
}
The common Paint event. We calculate the relative position of the image..
void btn_Paint(object sender, PaintEventArgs e)
{
Button btn = sender as Button;
e.Graphics.DrawImage(img, new Point(iLoc.X - btn.Left, iLoc.Y - btn.Top));
}
Note that if the Buttons are nested deeper you need to adapt the calculation to include all levels of nesting!
The TabPage Paint event:
private void tabPage5_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawImage(img, iLoc);
}
Try BringToFront method, it brings the control to the front of the z-order.
See this reference on MSDN: https://msdn.microsoft.com/en-us/library/system.windows.forms.control.bringtofront(v=vs.110).aspx
The problem isn't that I don't know how to make a border-less form re-sizable, or to how to draw a border. The problem is what happens when you re-size the form with that custom border.
Here is a screenshot, because I don't know how to explain it:
Here is how I created the border (currently):
private void Form1_Paint(object sender, PaintEventArgs e)
{
int width = 1;
Rectangle rec = this.ClientRectangle;
ButtonBorderStyle bbs = ButtonBorderStyle.Solid;
Color clr = Color.Gray;
ControlPaint.DrawBorder(e.Graphics, rec, clr, width, bbs, clr, width, bbs, clr, width, bbs, clr, width, bbs);
}
As for re-sizing a border-less form; I created a repository for the project.
Resize Custom Border - Bitbucket
I don't have any idea as to why this happens, so I wouldn't know where to begin. I just need to draw a border without it doing this. I have tried other ways of drawing one, but the results were the same.
Hopefully this and the repository becomes useful for anyone trying to do the same.
Thank you for taking your time to read if you did.
Try to use Graphics.DrawRectangle instead of DrawBorder
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Single fWidth = 5.0f;
Rectangle r = new Rectangle(0,0,this.ClientRectangle.Width-1,this.ClientRectangle.Height-1);
e.Graphics.DrawRectangle(new Pen(Color.Gray, fWidth), r);
}
protected override void OnResize(EventArgs e)
{
base.OnResize(e);
this.Invalidate();
}
Use Graphic library :
Step 1: Override the OnPaint handler for your main form
Step 2: Define a rectangle that covers your current form
Step 3: Draw the defined rectangle
protected override void OnPaint(PaintEventArgs e)
{
Rectangle r = new Rectangle(0,0,this.ClientRectangle.Width-1,this.ClientRectangle.Height-1);
e.Graphics.DrawRectangle(new Pen(Color.Gray, 1.0f), r);
}
You may also implement this using a condition statement like:
this.form.Resize += // some handler1
//in hadler1
{
this.form.Paint += // Your new paint handler2
}
//in handler2
{
Rectangle r = new Rectangle(0,0,this.ClientRectangle.Width-1,this.ClientRectangle.Height-1);
e.Graphics.DrawRectangle(new Pen(Color.Gray, 1.0f), r);
}
I have a Panel called panel1 and I am trying to draw a line on my panel1 using this code:
var g = panel1.CreateGraphics();
var p = new Pen(Color.Black, 3);
var point1 = new Point(234,118);
var point2 = new Point(293,228);
g.DrawLine(p, point1, point2);
But nothing is showing up. Any ideas? This is in a windows form.
Handle the Panel's Paint event and put it in there. What's happening is that it's being drawn once in the constructor but then being drawn over in the Paint event everytime it's called.
private void panel1_Paint(object sender, PaintEventArgs e)
{
base.OnPaint(e);
using(Graphics g = e.Graphics)
{
var p = new Pen(Color.Black, 3);
var point1 = new Point(234,118);
var point2 = new Point(293,228);
g.DrawLine(p, point1, point2);
}
}
Put it in some event after the form has been created and shown on the screen and it should work fine.
It's best to put it in the Paint event, as keyboardP stated, but it will not show up if called before the form is shown on the screen.
To test this you can add a button and add the code to the click event:
private void button1_Click(object sender, EventArgs e)
{
using (Graphics g = panel1.CreateGraphics())
{
g.DrawLine(new Pen(Color.Back, 3), new Point(234,118), new Point(293,228));
}
}
To see your drawing - you can simply make a button with a Click Event and draw when the button is clicked. For example:
private void btnDraw_Click(object sender, EventArgs e)
{
Graphics dc = drawingArea.CreateGraphics();
Pen BlackPen = new Pen(Color.Black, 2);
dc.DrawLine(BlackPen, 0, 0, 200, 200);
BlackPen.Dispose();
dc.Dispose();
}
Oh, and by the way "drawingArea" is the (Name) of either a PictureBox or Panel you have added to your form (to draw in it).
If you follow the other answers and still your drawings are not showing up try removing all controls from the control that is being drawn to. The other controls may be covering whatever you are trying to draw.
private void button2_Click(object sender, EventArgs e)
{
panel1.Paint += new PaintEventHandler(
(object sender1, PaintEventArgs e1) => {
var p = new Pen(Color.Black, 3);
var point1 = new Point(234, 118);
var point2 = new Point(293, 228);
e1.Graphics.DrawLine(p, point1, point2);
}
);
panel1.Invalidate();
}