iOS之CATextLayer属性简介

1、CATextLayer简介

　　CATextLayer快速高效简单地来渲染纯文本、NSAttributedString

/* The text layer provides simple text layout and rendering of plain
 * or attributed strings. The first line is aligned to the top of the
 * layer. */

NS_ASSUME_NONNULL_BEGIN

CA_CLASS_AVAILABLE (10.5, 2.0, 9.0, 2.0)
@interface CATextLayer : CALayer
{
@private
    struct CATextLayerPrivate *_state;
}

//渲染的字符串
@property(nullable, copy) id string;

//字体
@property(nullable) CFTypeRef font;

//字号
@property CGFloat fontSize;

//文字颜色
@property(nullable) CGColorRef foregroundColor;

//是否换行，默认NO
@property(getter=isWrapped) BOOL wrapped;

//枚举：设置截断模式
@property(copy) NSString *truncationMode;

//枚举：设置对其模式
@property(copy) NSString *alignmentMode;

//文字是否像素化，默认NO
@property BOOL allowsFontSubpixelQuantization;

@end

/* Truncation modes. */

CA_EXTERN NSString * const kCATruncationNone    //不剪裁，默认
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCATruncationStart   //剪裁开始部分
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCATruncationEnd     //剪裁结束部分
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCATruncationMiddle  //剪裁中间部分
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);

/* Alignment modes. */

CA_EXTERN NSString * const kCAAlignmentNatural  //默认
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCAAlignmentLeft     //左对齐
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCAAlignmentRight    //右对齐
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCAAlignmentCenter   //居中对齐
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);
CA_EXTERN NSString * const kCAAlignmentJustified    //两端对齐
CA_AVAILABLE_STARTING (10.5, 3.2, 9.0, 2.0);

NS_ASSUME_NONNULL_END