NSString drawAtPoint: and kCGTextFillClip, why doesn't it work?

I am facing a problem with NSString method drawAtPoint and kCGTextFillClip. I needed to create a UILabel with a gradient instead of a simple color, so I've subclassed it and overrode the drawRect method. I managed to get what I wanted by using the function CGContextShowTextAtPoint, but it doesn't handle UTF-8 properly, which is essential to me.

I am aware that this is a common problem so after searching for a bit, I found out that I could use drawAtPoint to solve this encoding problem. Indeed, the text is now showing properly. The problem is I don't know how to make kCGTextFillClip work anymore.

Look at the result.

As you can see, it seems to clip to the first letter just fine, but not after that. Do you have any idea on how to solve this issue?

Here's the code I'm using :

- (void)drawRect:(CGRect)rect { 
CGContextRef theContext = UIGraphicsGetCurrentContext();
CGRect viewBounds = self.bounds;

CGContextSaveGState(theContext);

CGContextTranslateCTM(theContext, 0.0, viewBounds.size.height/2 + 开发者_Python百科1);

CGContextSetTextDrawingMode(theContext, kCGTextFillClip);

[self.text drawAtPoint:CGPointMake(0, 0) withFont:[UIFont fontWithName:@"Helvetica-Bold" size:11.5]];

// Creation of the gradient
CGFloat locations[2] = { 0.0f, 1.0f };
CGFloat components[8] = { 
    190.0/255, 190.0/255, 190.0/255, 1.0, // Start color
    113.0/255, 113.0/255, 113.0/255, 1.0 // End color
};
CGColorSpaceRef rgbColorspace = CGColorSpaceCreateDeviceRGB();
CGGradientRef gradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, 2);

CGPoint topCenter = CGPointMake(CGRectGetMidX(viewBounds), 0.0f);
CGPoint midCenter = CGPointMake(CGRectGetMidX(viewBounds), CGRectGetMidY(viewBounds));


CGContextDrawLinearGradient(theContext, gradient, topCenter, midCenter, 0);

Thank you!

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Try and draw letter by letter?