Draw Line using CGContext - iphone

Question

I want to draw line in table view cell so that I can place textfield & switch in single cell. I increased the height of cell. How can I draw line in cell?
I have subclass of UIView which contains following code
//Get the CGContext from this view
CGContextRef context = UIGraphicsGetCurrentContext();
//Set the stroke (pen) color
CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor);
//Set the width of the pen mark
CGContextSetLineWidth(context, 1.0);
// Draw a line
//Start at this point
CGContextMoveToPoint(context, 10.0, 30.0);
//Give instructions to the CGContext
//(move "pen" around the screen)
CGContextAddLineToPoint(context, 310.0, 30.0);
//Draw it
CGContextStrokePath(context);
Then I have a tableViewController with grouped table style. In cellForRowAtIndexPath I have following code
//code to add textfield
DrawLineView *drawLine = [[DrawLineView alloc]init];
[cell addSubview:drawLine];
//code add switch
But it is not drawing any line. I can't use 2 different cells. I have to Please help me. This is my first to deal with graphics i iphone. Thanks

Answer 1

If all you want to do is draw a line, it would be a lot better to use a CAShapeLayer, pass it a path with a line, and then attach that as a sublayer of the cells content view. The table should perform better than using a view with a custom drawRect.
Example of drawing a line via CALayer and a path:
// You'll also need the QuartzCore framework added to the project
#import <QuartzCore/QuartzCore.h>
CAShapeLayer *lineShape = nil;
CGMutablePathRef linePath = nil;
linePath = CGPathCreateMutable();
lineShape = [CAShapeLayer layer];
lineShape.lineWidth = 4.0f;
lineShape.lineCap = kCALineCapRound;;
lineShape.strokeColor = [[UIColor blackColor] CGColor];
int x = 0; int y = 0;
int toX = 30; int toY = 40;
CGPathMoveToPoint(linePath, NULL, x, y);
CGPathAddLineToPoint(linePath, NULL, toX, toY);
lineShape.path = linePath;
CGPathRelease(linePath);
[self.layer addSublayer:lineShape];

Answer 2

Two things...
First, you usually don't draw into the cell itself.
You normally draw into the content view. Sometimes it makes sense draw into the cell's backgroundView or selectedBackgroundView.
[cell.contentView addSubview:drawLine];
Second, the default cell text labels cell.textLabel and cell.detailTextLabel have non-transparent background. Try setting their background colors to [UIColor clearColor].
Edit: one more thing: you need to set a proper frame for your drawLine
DrawLineView *drawLine = [[DrawLineView alloc]initWithFrame:cell.contentView.bounds];

Answer 3

I think a very simplified way of drawing a line is to create a UIView and fill it with desired color, then choose its width accordingly, and setup height to be 1 pixel like so:
var lineView : UIView = {
let view = UIView()
view.backgroundColor = UIColor.blackColor()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
self.view.addSubview(lineView)
self.view.addConstraints(NSLayoutConstraint.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[view]|", options: NSLayoutFormatOptions(), metrics: nil, views: ["view": lineView])))
self.view.addConstraints(NSLayoutConstraint.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-50-[view(1)]", options: NSLayoutFormatOptions(), metrics: nil, views: ["view": lineView])))