CGContext和视网膜显示

Question

伙计们,这是我的代码:

- (void) renderPageAtIndex:(NSUInteger)index inContext:(CGContextRef)ctx {
    //background
    CGContextSetFillColorWithColor(ctx, [[UIColor colorWithRed:((float)238 / 255.0f) green:((float)233 / 255.0f) blue:((float)215 / 255.0f) alpha:1] CGColor]);
    CGContextFillRect(ctx, CGRectInset(leavesView.bounds, 0, 0));
    //text
    CGContextSetTextDrawingMode(ctx, kCGTextFill);
    CGContextSetTextMatrix(ctx, CGAffineTransformMake(1.0, 0.0, 0.0, 1.0, 0.0, 0.0));
    CGContextSetFillColorWithColor(ctx, [[UIColor blackColor] CGColor]);
    UIGraphicsPushContext(ctx);

    CGContextSaveGState(ctx);
    CGContextTranslateCTM(ctx, 0.1f, leavesView.bounds.size.height);
    CGContextScaleCTM(ctx, 1.0f, -1.0f);

    CGRect textRect = CGRectMake(5, 5, leavesView.bounds.size.width-10, leavesView.bounds.size.height-10);
    if (pages.count > 0 && pages.count-1 >= index) {
        [[pages objectAtIndex:index] drawInRect:textRect withFont:font lineBreakMode:UILineBreakModeWordWrap alignment:UITextAlignmentLeft];
    }

    CGContextRestoreGState(ctx);

    UIGraphicsPopContext();
}

它在iPhone 2G,3G,3GS上运行完美,但在新机型上我遇到了问题.

在视网膜上,文字不会像标准中那样使分辨率加倍.

你有什么想法吗？

Answer 1

尝试像这样设置图层contentScale变量:

layer.contentsScale = [UIScreen mainScreen].scale;

这应该使代码适应视网膜/非视网膜显示.