使用drawInRect:withAttributes对齐文本:

Question

在我的应用程序的iOS 5版本中,我有:

[self.text drawInRect: stringRect
             withFont: [UIFont fontWithName: @"Courier" size: kCellFontSize]
        lineBreakMode: NSLineBreakByTruncatingTail
            alignment: NSTextAlignmentRight];

我正在升级iOS 7.上面的方法已被弃用.我现在正在使用drawInRect:withAttributes : . 的属性参数是一个NSDictionary对象.我可以得到drawInRect:withAttributes:使用这个来处理以前的字体参数:

      UIFont *font = [UIFont fontWithName: @"Courier" size: kCellFontSize];

      NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys: font, NSFontAttributeName,
                                  nil];

      [self.text drawInRect: stringRect
             withAttributes: dictionary];

我将哪些键值对添加到字典中以获取NSLineBreakByTruncatingTail和NSTextAlignmentRight？

Answer 1

有一个键可以设置文本的段落样式(包括换行模式,文本对齐等).

来自docs:

NSParagraphStyleAttributeName

该属性的值是一个NSParagraphStyle对象.使用此属性可将多个属性应用于一系列文本.如果未指定此属性,则字符串将使用默认段落属性,如defaultParagraphStyle方法返回的那样NSParagraphStyle.

所以,你可以尝试以下方法:

UIFont *font = [UIFont fontWithName:@"Courier" size:kCellFontSize];

/// Make a copy of the default paragraph style
NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
/// Set line break mode
paragraphStyle.lineBreakMode = NSLineBreakByTruncatingTail;
/// Set text alignment
paragraphStyle.alignment = NSTextAlignmentRight;

NSDictionary *attributes = @{ NSFontAttributeName: font,
                    NSParagraphStyleAttributeName: paragraphStyle };

[text drawInRect:rect withAttributes:attributes];

Answer 2

代码就是这样:

CGRect textRect = CGRectMake(x, y, length-x, maxFontSize);
UIFont *font = [UIFont fontWithName:@"Courier" size:maxFontSize];
NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
    paragraphStyle.lineBreakMode = NSLineBreakByTruncatingTail;


   paragraphStyle.alignment = NSTextAlignmentRight;
    NSDictionary *attributes = @{ NSFontAttributeName: font,
                                  NSParagraphStyleAttributeName: paragraphStyle,
                                  NSForegroundColorAttributeName: [UIColor whiteColor]};
[text drawInRect:textRect withAttributes:attributes];