iOS 练习项目 Landmarks （二）：自定义 UITableViewCell

iOS 练习项目 Landmarks （二）：自定义 UITableViewCell

自定义 UITableViewCell：PlaceCell

相较于AccessoryType为UITableViewCellAccessoryDisclosureIndicator的UITableViewCell，只需要在textLabel和箭头中间插入一个UIButton，作为收藏按钮。

同时修改了frame的样式，现在PlaceCell会在上方空出10px的空位，imageView不会占满整个Cell。

PlaceCell.h：

#import <UIKit/UIKit.h>
#import "Place.h"

NS_ASSUME_NONNULL_BEGIN

@interface PlaceCell : UITableViewCell

@property (nonatomic) UIButton *starButton;

//@property (nonatomic, strong) UIImage *photo;
//@property (nonatomic, strong) NSString *labelStr;

@end

NS_ASSUME_NONNULL_END

PlaceCell.m：

#import "PlaceCell.h"

@interface PlaceCell()
{
    UIButton *_starButton;
}
@end

@implementation PlaceCell

//@synthesize photo;
//@synthesize labelStr;

- (void)awakeFromNib {
    [super awakeFromNib];
    // Initialization code
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state
}

- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self)
    {
        [self initSubView];
    }
    return self;
}

- (void)setFrame:(CGRect)frame
{
    frame.origin.y += 10;
    frame.size.height -= 10;
    [super setFrame:frame];
}

#pragma mark - 初始化视图

- (void)initSubView
{
    CGRect buttonFrame = CGRectMake(320, 12, 25, 25);
    // 创建并设置 UIButton 对象
    self.starButton = [UIButton buttonWithType:UIButtonTypeCustom];
    self.starButton.frame = buttonFrame;
    // 设置样式
    [self.starButton setTitle:@"" forState:UIControlStateNormal];
    [self.starButton setImage:[UIImage imageNamed:@"Image_star"] forState:UIControlStateNormal];
    [self.starButton setImage:[UIImage imageNamed:@"Image_starred"] forState:UIControlStateSelected];
    [self setAccessoryType:UITableViewCellAccessoryDisclosureIndicator]; // 辅助指示视图为箭头
    // 添加目标-动作对
    [self.starButton addTarget:self action:@selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];
    
    [self.contentView addSubview:self.starButton];
}

- (void)btnClicked:(UIButton *)sender
{
    sender.selected = !sender.selected;
    NSLog(@"tag: %ld", sender.tag);
}

starButton 的点击事件

PlaceCell新增的一个starButton，分别设置了常规状态和点击状态的图片，为starButton添加了一个目标-动作对，在单击收藏按钮时会改变按钮的状态，进而切换显示的图片。

读plist进行数据源初始化

一个一个addObject太慢了，而且代码太长，把数据保存在plist，读它来进行places数组的初始化：

#pragma mark - 初始化 places 数组

- (void)initPlaces
{
    // 创建数组
    self.places = [NSMutableArray array];
    // 读文件
    NSBundle *bundle = [NSBundle mainBundle];
    NSURL *plistUrl = [bundle URLForResource:@"PlaceInfo" withExtension:@"plist"];
    NSDictionary *placesInfoDic = [NSDictionary dictionaryWithContentsOfURL:plistUrl];
    // 遍历
    for (int i = 0; i< [placesInfoDic count]; i++)
    {
        NSString *key = [[NSString alloc] initWithFormat:@"%i", i];
        NSDictionary *placeInfo = [placesInfoDic objectForKey:key];
        // 初始化对象
        Place *place = [Place alloc];
        [place setSight:[placeInfo objectForKey:@"sight"]];
        [place setScenicArea:[placeInfo objectForKey:@"scenicArea"]];
        [place setState:[placeInfo objectForKey:@"state"]];
        [place setPicture:[UIImage imageNamed:[placeInfo objectForKey:@"pictureUrl"]]];
        // [place setFavorite:[placeInfo valueForKey:@"favorite"]]; // wrong
        [place setFavorite:[(NSNumber *)[placeInfo objectForKey:@"favorite"] boolValue]];
        NSLog(@"placeInfo favorite: %@", [placeInfo objectForKey:@"favorite"]);
        [place setLocation:[[CLLocation alloc] initWithLatitude:[[placeInfo objectForKey:@"latitude"] doubleValue] longitude:[[placeInfo objectForKey:@"longitude"] doubleValue]]];
        NSLog(@"%@", place);
        // Place *place = [[Place alloc] initWithSight:[placeInfo objectForKey:@"sight"] scenicArea:[placeInfo objectForKey:@"scenicArea"] state:[placeInfo objectForKey:@"state"] picture:[UIImage imageNamed:[placeInfo objectForKey:@"pictureUrl"]] favorite:[placeInfo objectForKey:@"favorite"] location:[[CLLocation alloc] initWithLatitude:[[placeInfo objectForKey:@"latitude"] doubleValue] longitude:[[placeInfo objectForKey:@"longitude"] doubleValue]]];
        // 插入数组
        [self.places addObject:place];
    }
}

数据保存在一个名叫placeInfo的plist里：

注意Boolean转BOOL的细节：将Boolean用一个NSNumber类封装，再用boolValue方法取出BOOL值。

杂项：Place 的 description

重写了模型 Place 的 description 方法，主要用于在 initPlaces 方法中检验 Place 实例是否初始化成功。

-(NSString *)description
{
    return [[NSString alloc] initWithFormat:@"sight = %@, scenicArea = %@, state = %@, picture = %@, favorite = %d, location = %@",[self sight], [self scenicArea], [self state], [self picture], [self favorite] , [self location]];

运行效果

点击收藏按钮会切换按钮的状态，也就会改变按钮的图片。

参考

1. IOS开发学习笔记027-UITableView 使用模型对象
2. iOS：使用Table View类(表视图）实现显示数据列表详解
3. iOS学习之设置UITableViewCell之间的间距(推荐第四种)
4. 设置自定义UITableViewCell之间的间距