Draw Dots like Matrix Structure on iphone sdk - iphone

Question

I want to Draw dots like a Matrix Structure in iphone sdk.
if i want generate dots columns and rows (like 2x2,3x3,4x4).
but i have no idea for this generation.
i want output like below image.
any help for example code or tutorial..!

Answer 1

A simple Solution would be:
- (void)drawRect:(CGRect)rect {
int n = 12; // row and column count
int padding = 5; // distance beetween dots
float radius = MIN((rect.size.width-(n+1)*padding)/(n*2), (rect.size.height-(n+1)*padding)/(n*2)); // radius depending on rect size
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [[UIColor whiteColor] CGColor]); // background color
CGContextFillRect(context, rect); // setting background color
CGContextSetFillColorWithColor(context, [[UIColor blackColor] CGColor]); // dot color
for (int y = 0; y<n; y++) {
for (int x = 0; x<n; x++) {
CGContextAddArc(context, padding+radius+(padding+radius*2)*x, padding+radius+(padding+radius*2)*y, radius, 0, M_PI*2, 0); // adding dot path
CGContextFillPath(context); // drawing dot path
}
}
}

Answer 2

You use this code ...
- (void)drawRect:(CGRect)rect
{
CGContextRef contextRef = UIGraphicsGetCurrentContext();
CGContextSetRGBFillColor(contextRef, 0, 0, 255, 0.1);
//CGContextSetRGBFillColor(contextRef, 0, 10, 200, 0.2);
CGContextSetRGBStrokeColor(contextRef, 0, 0, 255, 0.5);
// Draw a circle (filled)
//CGContextFillEllipseInRect(contextRef, CGRectMake(100, 100, 25, 25));
// Draw a circle (border only)
CGContextStrokeEllipseInRect(contextRef, CGRectMake(100, 100, 25, 25));
// Get the graphics context and clear it
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextClearRect(ctx, rect);
// Draw a green solid circle
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(20, 50, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(50, 50, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(80, 50, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(110, 50, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(140, 50, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(170, 50, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(20, 100, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(50, 100, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(80, 100, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(110, 100, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(140, 100, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(170, 100, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(20, 150, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(50, 150, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(80, 150, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(110, 150, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(140, 150, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(170, 150, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(20, 200, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(50, 200, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(80, 200, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(110, 200, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(140, 200, 8, 8));
CGContextSetRGBFillColor(ctx, 0, 255, 0, 1);
CGContextFillEllipseInRect(ctx, CGRectMake(170, 200, 8, 8));
}
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