第一篇 UILabel

 

 

- (void)viewDidLoad {
    [super viewDidLoad];
    
    
//    @property(nullabel, nonatomic,copy)   NSString  *text;   // label上要顯示的文字     
 @property(null_resettable, nonatomic,strong) UIFont *font;            // default is nil (system font 17 plain)
//    @property(null_resettable, nonatomic,strong) UIColor     *textColor;       // default is nil (text draws black)
//    @property(nullabel, nonatomic,strong) UIColor            *shadowColor;     // default is nil (no shadow)陰影顏色
//    @property(nonatomic)        CGSize             shadowOffset;    // default is CGSizeMake(0, -1) -- a top shadow
//    @property(nonatomic)        NSTextAlignment    textAlignment;   // default is NSTextAlignmentLeft
    //    @property(nonatomic)        NSLineBreakMode    lineBreakMode;   // default is NSLineBreakByTruncatingTail. used for single and multiple lines of text
    // 控制文字超出label範圍後，怎樣顯示。
    //    // NSParagraphStyle
    //    typedef NS_ENUM(NSInteger, NSLineBreakMode) {
    //        NSLineBreakByWordWrapping = 0,         // Wrap at word boundaries, default
    //        NSLineBreakByCharWrapping, //自動折行，一個單詞可能現實在這行末尾，和下一行開始        // Wrap at character boundaries
    //        NSLineBreakByClipping,    //自動折行，一個單詞始終顯示在一行    // Simply clip（簡單的剪輯）
    //        NSLineBreakByTruncatingHead,    // Truncate at head of line: "...wxyz"
    //        NSLineBreakByTruncatingTail,    // Truncate at tail of line: "abcd..."
    //        NSLineBreakByTruncatingMiddle    // Truncate middle of line:  "ab...yz"
    //    } NS_ENUM_AVAIlabel(10_0, 6_0);
    
    //    label.lineBreakMode = NSLineBreakByTruncatingTail;
//
//    // the underlying attributed string drawn by the label, if set, the label ignores the properties above.
//    @property(nullabel, nonatomic,copy)   NSAttributedString *attributedText NS_AVAIlabel_IOS(6_0);  // default is nil(富文本，圖文混排爲這個類型)
//    
//    // the 'highlight' property is used by subclasses for such things as pressed states. it's useful to make it part of the base class as a user property
//    
//    @property(nullabel, nonatomic,strong)               UIColor *highlightedTextColor; // default is nil（高亮文字的顏色）
//    @property(nonatomic,getter=isHighlighted) BOOL     highlighted;          // default is NO
//    
//    @property(nonatomic,getter=isUserInteractionEnabled) BOOL userInteractionEnabled;  // default is NO
//    @property(nonatomic,getter=isEnabled)                BOOL enabled;                 // default is YES. changes how the label is drawn
//    
//    // this determines the number of lines to draw and what to do when sizeToFit is called. default value is 1 (single line). A value of 0 means no limit
//    // if the height of the text reaches the # of lines or the height of the view is less than the # of lines allowed, the text will be
//    // truncated using the line break mode.
//    
//    @property(nonatomic) NSInteger numberOfLines;
//    
//    // these next 3 property allow the label to be autosized to fit a certain width by scaling the font size(s) by a scaling factor >= the minimum scaling factor
//    // and to specify how the text baseline moves when it needs to shrink the font.
    // 文字本身調整大小去適應label的寬度
//    @property(nonatomic) BOOL adjustsFontSizeToFitWidth;         // default is NO
    // 文字的基線（下面有介紹）
//    @property(nonatomic) UIBaselineAdjustment baselineAdjustment; // default is UIBaselineAdjustmentAlignBaselines
    // 文字最小的縮小倍數
//    @property(nonatomic) CGFloat minimumScaleFactor NS_AVAIlabel_IOS(6_0); // default is 0.0
//    

//    // Tightens inter-character spacing in attempt to fit lines wider than the availabel space if the line break mode is one of the truncation modes before starting to truncate.
//    // The maximum amount of tightening performed is determined by the system based on contexts such as font, line width, etc.
//    @property(nonatomic) BOOL allowsDefaultTighteningForTruncation NS_AVAIlabel_IOS(9_0); // default is NO
//    
//    // override points. can adjust rect before calling super.
//    // label has default content mode of UIViewContentModeRedraw
//    
//    - (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines;
//    - (void)drawTextInRect:(CGRect)rect;
//    
//    
//    // Support for constraint-based layout (auto layout)
//    // If nonzero, this is used when determining -intrinsicContentSize for multiline labels
//    @property(nonatomic) CGFloat preferredMaxLayoutWidth NS_AVAIlabel_IOS(6_0);
//    
//    
//    // deprecated:
//    
//    @property(nonatomic) CGFloat minimumFontSize NS_DEPRECATED_IOS(2_0, 6_0) __TVOS_PROHIBITED; // deprecated - use minimumScaleFactor. default is 0.0
//    
//    // Non-functional.  Hand tune by using NSKernAttributeName to affect tracking, or consider using the allowsDefaultTighteningForTruncation property.
//    @property(nonatomic) BOOL adjustsLetterSpacingToFitWidth NS_DEPRECATED_IOS(6_0,7_0) __TVOS_PROHIBITED;
    
    UILabel *label = [[UILabel alloc] init];
    label.frame = CGRectMake(0, 20, 100, 50);
    label.backgroundColor = [UIColor orangeColor];
    label.text = @"But thanks to last autumn's";
//    label.shadowOffset = CGSizeMake(10, 10); //文字陰影偏移量
//    label.shadowColor = [UIColor redColor]; //文字陰影顏色
    
    //文本文字自適應大小
    label.adjustsFontSizeToFitWidth = YES;
//    label.baselineAdjustment = UIBaselineAdjustmentAlignCenters;
    //當adjustsFontSizeToFitWidth=YES時候，若是文本font要縮小時
    //baselineAdjustment這個值控制文本的基線位置，只有文本行數爲1是有效
    //有三種方式
    //typedef enum {
    //    UIBaselineAdjustmentAlignBaselines = 0, 默認值文本最上端於label中線對齊
    //    UIBaselineAdjustmentAlignCenters,//文本中線於label中線對齊
    //    UIBaselineAdjustmentNone,//文本最低端與label中線對齊
    //} UIBaselineAdjustment;
    
//    label.minimumFontSize = 12; // ios6.0及之後使用minimumScaleFactor
//    label.minimumScaleFactor = 0.9; //文字自適應寬度，最小的縮小倍數
    
//    label.adjustsLetterSpacingToFitWidth = YES; //控制文字間的間距適應寬度 9.0及之後使用下面的 allowsDefaultTighteningForTruncation
//    label.allowsDefaultTighteningForTruncation = YES;
    

//   CGRect rect = [label textRectForBounds:CGRectMake(0, 20, 180, 100) limitedToNumberOfLines:0];
//    
//    NSLog(@"rect %@",NSStringFromCGRect(rect));
    
    // 自動佈局
//    label.preferredMaxLayoutWidth = 50;
    
    label.numberOfLines = 0; // 顯示多少行，0爲自動換行
    [self.view addSubview:label];
    
}