IOS7笔记-5、视图控制器生命周期

1、字体属性的添加方法

- (IBAction)changeBodySelectedColorMatchBackgroundOfButton:(UIButton *)sender {
    [self.body.textStorage addAttribute:NSForegroundColorAttributeName
                                  value:sender.backgroundColor
                                  range:self.body.selectedRange];
}

- (IBAction)outlineBodySelection {
    [self.body.textStorage addAttributes:@{NSStrokeWidthAttributeName: @-3,
                                           NSStrokeColorAttributeName: [UIColor blackColor]} range:self.body.selectedRange];
}
- (IBAction)unOutlineBodySelection {
    [self.body.textStorage removeAttribute:NSStrokeWidthAttributeName
                                     range:self.body.selectedRange];
}

2、按钮字体描边设置，一般在viewDidLoad中实现

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    NSMutableAttributedString *title =
    [[NSMutableAttributedString alloc] initWithString:self.outlineButton.currentTitle];
    [title setAttributes:@{NSStrokeWidthAttributeName: @3,
                           NSStrokeColorAttributeName: self.outlineButton.tintColor}
                   range:NSMakeRange(0, [title length])];
    [self.outlineButton setAttributedTitle:title forState:UIControlStateNormal];
}

3、使用用户设置的字体

-(void)usePerferredFont
{
    self.body.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
    self.headline.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
}

4、添加广播与去除广播一般分别在viewWillAppear和viewWillDisappear中设置

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self usePerferredFont];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(perferredFontChanged:)
                                                 name:UIContentSizeCategoryDidChangeNotification object:nil];
}

-(void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIContentSizeCategoryDidChangeNotification
                                                  object:nil];
}

-(void)perferredFontChanged:(NSNotification *)notification
{
    [self usePerferredFont];
}

-(void)usePerferredFont
{
    self.body.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
    self.headline.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
}

5、viewDidLoad中设置初始化实例相关，viewWillAppear则表示与界面相关已经初始化完毕，若有需要耗时资源则亦放置在viewWillAppear中实现！