< IOS开发 >使用CGContextRef绘制文字时的设置

        NSString *str = @"hello";
        //字体
        UIFont *font = [UIFont systemFontOfSize:16.0];
        //文本风格，设置居中
        NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
        [paragraphStyle setAlignment:NSTextAlignmentCenter];
        //文本位置
        CGRect iRect = CGRectMake(0, 0, 100, 20);
        //打印文本
        [str drawInRect:iRect withAttributes:@{NSFontAttributeName:font,NSParagraphStyleAttributeName:paragraphStyle}];