C# – Problem with using Paint event in c#

c++

I have used this below code before and was working perfectly. When I use the same
in one of my window form, the color of the form is not changing.

I mean after the page loads it shows the default color of the form. But when I try to debug the code below, it changes the color of the form perfectly. The problem is, after executing the last line of the code the color of the form goes back to the default color.

Am I missing something?

The form looks like a windows taskbar, and it has one tab control in it.

private void TaskBar_Paint(object sender, PaintEventArgs e)
{
    Graphics mGraphics = e.Graphics;
    Pen pen1 = new Pen(Color.FromArgb(96, 155, 173), 1);

    Rectangle Area1 = new Rectangle(0, 0, this.Width - 2, this.Height - 2);
    LinearGradientBrush LGB = new LinearGradientBrush(Area1,
        Color.FromArgb(96, 155, 173),
        Color.FromArgb(245, 251, 251),
        LinearGradientMode.Vertical);
    mGraphics.FillRectangle(LGB, Area1);
    mGraphics.DrawRectangle(pen1, Area1);
}

Best Solution

There isn't much to go on here. What is this handler attached to? The Paint event of the Form? If so, you should override OnPaint() instead of attaching to the handler. My guess is that some other method is doing some painting too. You need to track that down. Without more code, it is not very likely that anyone here can help you. Sorry.

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C# – Should ‘using’ directives be inside or outside the namespace

There is actually a (subtle) difference between the two. Imagine you have the following code in File1.cs:

// File1.cs
using System;
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Now imagine that someone adds another file (File2.cs) to the project that looks like this:

// File2.cs
namespace Outer
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The compiler searches Outer before looking at those using directives outside the namespace, so it finds Outer.Math instead of System.Math. Unfortunately (or perhaps fortunately?), Outer.Math has no PI member, so File1 is now broken.

This changes if you put the using inside your namespace declaration, as follows:

// File1b.cs
namespace Outer.Inner
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Now the compiler searches System before searching Outer, finds System.Math, and all is well.

Some would argue that Math might be a bad name for a user-defined class, since there's already one in System; the point here is just that there is a difference, and it affects the maintainability of your code.

It's also interesting to note what happens if Foo is in namespace Outer, rather than Outer.Inner. In that case, adding Outer.Math in File2 breaks File1 regardless of where the using goes. This implies that the compiler searches the innermost enclosing namespace before it looks at any using directive.

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Of course, you will want to add validation and whatnot, but that is the gist of it.

Best Solution

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