自己对于instancetype的理解和应用iOS开发的过程

来源：互联网发布：mac照片如何归类编辑：程序博客网时间：2024/04/30 07:18

- (instancetype)initWithCourse:(TTCourse *)aCourse type:(TTCourseCellType)aType

{

self = [superinit];//这里是必须要写的对于重写init方法来说，开头就是这么写的不能忘记。

if (self !=nil)

{

self.course = aCourse;

self.clipsToBounds =YES;

//封面图

self.coverImageView = [[UIImageViewalloc] initWithFrame:CGRectMake(15, 15, 60 , 60)];

[self.coverImageViewsd_setImageWithURL:[NSURLURLWithString:self.course.coverURL]placeholderImage:[UIImageimageNamed:@"album_holder"]];

/**

* 圆角从2改成3

self.coverImageView.layer.cornerRadius = 3.0f;

[self.contentViewaddSubview:self.coverImageView];

//曲目名字

self.titleLabel = [[UILabelalloc] initWithFrame:CGRectMake(90, 17, 200, 21)];

self.titleLabel.text =self.course.title;

self.titleLabel.font =TTCommonFont(20);

/**

* 设置字体的风格

[self.contentViewaddSubview:self.titleLabel];

//作者

self.authorLabel = [[UILabelalloc] initWithFrame:CGRectMake(90, 44, 200, 15)];

self.authorLabel.text =self.course.artist;

self.authorLabel.font =TTCommonFont(12);

[self.contentViewaddSubview:self.authorLabel];

//难度

self.difficultyLabel = [[UILabelalloc] initWithFrame:CGRectMake(140, 100, 200, 20)];

self.difficultyLabel.font =TTCommonFont(14);

CGSize textSize = [self.difficultyLabel.textsizeWithAttributes:@{NSFontAttributeName :self.difficultyLabel.font}];

/**

* 72

for (int i = 0; i < 5; i++)

{

UIImage* image = i <self.course.difficulty.intValue ? [UIImageimageNamed:@"icon-difficulty-active@3x.png"] : [UIImageimageNamed:@"icon-difficulty-default@3x.png"];

UIImageView* iv = [[UIImageViewalloc] initWithImage:image];

CGPoint center =self.difficultyLabel.center;

center.x += (textSize.width / 2 + i * 10)-146;

center.y=72.0;

iv.center = center;

[self.contentViewaddSubview:iv];

}

switch (aType) {

caseECourseTypePractice:

// 加入进度标识

self.progressView = [[MLVCircularProgressViewalloc] initWithFrame:CGRectMake(SYSTEM_SCREEN_WIDTH - 44, 30, 25, 25)];

self.progressView.center =self.downloadButton.center;

self.progressView.shapeColor = [UIColorcolorWithHexString:@"#cbbcad"];

self.progressView.hidden =YES;

[self.contentViewaddSubview:self.progressView];

break;

caseECourseTypeFavorite:

// 加入下载按钮

self.downloadButton = [UIButtonbuttonWithType:UIButtonTypeCustom];

[self.downloadButtonsetImage:[UIImageimageNamed:@"me_download_button"]forState:UIControlStateNormal];

self.downloadButton.frame =CGRectMake(SYSTEM_SCREEN_WIDTH - 44, 30, 44, 44);

[self.downloadButtonaddTarget:self

action:@selector(downloadAction:)

forControlEvents:UIControlEventTouchUpInside];

self.downloadButton.hidden =YES;

[self.contentViewaddSubview:self.downloadButton];

break;

caseECourseTypeCommentAndLike:

// 加入点赞和评论

break;

default:

break;

}

returnself;

}

这是对于自己的一个tableviewcell的自定义，这个重新写了init的方法，可以返回自己想要的产生的类型。

至于和id的区别还没有研究。id好像最终不能返回你想要的那个类。。。后续会补充

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