QQ好友列表 （UITableViewHeaderFooterView的使用）

1，除可以为TableView设置Header/Footer文字外，还可以设置View，这个view如果是单独定义的CLASS，需要继承自UITableViewHeaderFooterView

2，当父控件的FRAME发生改变时，会自动调用子控件的layoutSubView方法，可重写此方法，对子控件进行重写布局，但此重写方法第一行必须先调用相同的父类方法

TableView中的三个数据源方法一旦确定，也就自动确定了每个section的头部/尾部FRAME，这里是自动改变的，可以在UITableViewHeaderFooterView中重写layoutSubView方法，这个方法也是自动调的

3，TableViewHeaderFooterView像TableViewCell一样可以被TableView自动放入到缓存池中进行回收利用，但relaodData方法是重写创建Cell或HeaderFooterView的，实际上是重写创建的，和旧的内存地址是不一样的；当一个控件被添加到父类中时，会自动调用：didMoveToSuperview



#import <UIKit/UIKit.h>

@class TXFriendGroup, TXFriendHeaderView;

@protocol TXFriendHeaderViewDelegate <NSObject>

@optional

- (void)friendHeaderViewDidClickedNameView:(TXFriendHeaderView *)headerView;

@end

@interface TXFriendHeaderView : UITableViewHeaderFooterView

@property (nonatomic, weak) id<TXFriendHeaderViewDelegate> delegate;

@property (nonatomic, strong) TXFriendGroup *group;

+ (instancetype)friendHeaderViewWithTableView:(UITableView *)tableView;

@end

=============

#import "TXFriendCell.h"

#import "TXFriend.h"

@implementation TXFriendCell

+ (instancetype)friendCellWithTableView:(UITableView *)tableView

{

static NSString *ID = @"friendCell";

TXFriendCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];

if (cell == nil) {

cell = [[TXFriendCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:ID];

}

return cell;

}

- (void)setFriendData:(TXFriend *)friendData

{

_friendData = friendData;

self.imageView.image = [UIImage imageNamed:friendData.icon];

self.textLabel.text = friendData.name;

self.textLabel.textColor = friendData.isVip ? [UIColor redColor] : [UIColor blackColor];

self.detailTextLabel.text = friendData.intro;

}

@end

============

#import "TXFriendHeaderView.h"

#import "TXFriendGroup.h"

@interface TXFriendHeaderView()

@property (nonatomic, weak) UIButton *nameView;

@property (nonatomic, weak) UILabel *countView;

@end

@implementation TXFriendHeaderView

+ (instancetype)friendHeaderViewWithTableView:(UITableView *)tableView

{

static NSString *ID = @"friendGroup";

TXFriendHeaderView *headerView = [tableView dequeueReusableCellWithIdentifier:ID];

if (headerView == nil) {

headerView = [[TXFriendHeaderView alloc] initWithReuseIdentifier:ID];

}

return headerView;

}

- (id)initWithReuseIdentifier:(NSString *)reuseIdentifier

{

self = [super initWithReuseIdentifier:reuseIdentifier];

if (self) {

// 1

UIButton *nameView = [UIButton buttonWithType:UIButtonTypeCustom];

[nameView setBackgroundImage:[UIImage imageNamed:@"buddy_header_bg"] forState:UIControlStateNormal];

[nameView setBackgroundImage:[UIImage imageNamed:@"buddy_header_bg_highlighted"] forState:UIControlStateHighlighted];

[nameView setImage:[UIImage imageNamed:@"buddy_header_arrow"] forState:UIControlStateNormal];

[nameView setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

// Button内部有两个子控件，而控件一般是位于content中的，所以这里以conteng开头的水平对齐属性

nameView.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;

nameView.imageEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 0);

nameView.titleEdgeInsets = UIEdgeInsetsMake(0, 20, 0, 0);

nameView.imageView.contentMode = UIViewContentModeCenter;

nameView.imageView.clipsToBounds = NO;

[nameView addTarget:self action:@selector(nameViewClicked) forControlEvents:UIControlEventTouchUpInside];

[self.contentView addSubview:nameView];

self.nameView = nameView;

// 2

UILabel *countView = [[UILabel alloc] init];

// Label里面没有子控件了，直接写对齐属性

countView.textAlignment = NSTextAlignmentRight;

countView.textColor = [UIColor grayColor];

[self.contentView addSubview:countView];

self.countView = countView;

}

return self;

}

// 当父控件FRAME发生改变时，这个方法会被自动调用

// 父控件UITableHeaderFooterView 只要确定每一个组后，就会被自动放到每个section组的头部或尾部，这样他的FRAME就被改变了

- (void)layoutSubviews

{

[super layoutSubviews]; // 必须先调用父类的方法

self.nameView.frame = self.bounds;

CGFloat countW = 100;

CGFloat countH = self.bounds.size.height;

CGFloat countX = self.bounds.size.width - countW - 5;

CGFloat countY = 0;

self.countView.frame = CGRectMake(countX, countY, countW, countH);

[self didMoveToSuperview];//缓存池中取出的headerView可能那个三角形按钮是以前旧状态，所以再次调用一次检查

}

// 当前控件被添加到父控件时，就会自动调用下面的方面

- (void)didMoveToSuperview

{

if (self.group.isOpened) {

self.nameView.imageView.transform = CGAffineTransformMakeRotation(M_PI_2);

} else {

self.nameView.imageView.transform = CGAffineTransformMakeRotation(0);

}

}

- (void)setGroup:(TXFriendGroup *)group

{

_group = group;

[self.nameView setTitle:group.name forState:UIControlStateNormal];

self.countView.text = [NSString stringWithFormat:@"%@/%d ", group.online, group.friends.count];

}

- (void)nameViewClicked

{

self.group.opened = !self.group.isOpened;

if ([self.delegate respondsToSelector:@selector(friendHeaderViewDidClickedNameView:)]) {

[self.delegate friendHeaderViewDidClickedNameView:self];

}

}

@end

===================

#import "TXViewController.h"

#import "TXFriendGroup.h"

#import "TXFriendCell.h"

#import "TXFriendHeaderView.h"

@interface TXViewController () <TXFriendHeaderViewDelegate>

@property (nonatomic, strong) NSArray *groups;

@property (weak, nonatomic) IBOutlet UITableView *myTableView;

@end

@implementation TXViewController

- (void)viewDidLoad

{

[super viewDidLoad];

self.myTableView.rowHeight = 50;

self.myTableView.sectionHeaderHeight = 44;

}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

{

return self.groups.count;

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

TXFriendGroup *group = self.groups[section];

return group.isOpened ? group.friends.count : 0; // 子Cell关闭/显示 效果，其实就是控制组内部row的行数后，再刷新table

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

TXFriendCell *cell = [TXFriendCell friendCellWithTableView:tableView];

TXFriendGroup *group = self.groups[indexPath.section];

cell.friendData = group.friends[indexPath.row];

return cell;

}

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section

{

TXFriendHeaderView *headerView = [TXFriendHeaderView friendHeaderViewWithTableView:tableView];

headerView.group = self.groups[section];

headerView.delegate = self;

return headerView;

}

- (void)friendHeaderViewDidClickedNameView:(TXFriendHeaderView *)headerView

{

[self.myTableView reloadData];

}

- (NSArray *)groups

{

if(_groups == nil)

{

NSString *path = [[NSBundle mainBundle] pathForResource:@"friends.plist" ofType:nil];

NSArray *dictArray = [NSArray arrayWithContentsOfFile:path];

NSMutableArray *groupArray = [NSMutableArray array];

for (NSDictionary *dict in dictArray) {

TXFriendGroup *group = [TXFriendGroup groupWithDict:dict];

[groupArray addObject:group];

}

_groups = groupArray;

}

return _groups;

}

- (BOOL)prefersStatusBarHidden

{

return YES;

}

@end

===================

#import <UIKit/UIKit.h>

@class TXFriend;

@interface TXFriendCell : UITableViewCell

@property (nonatomic, strong) TXFriend *friendData;

+ (instancetype)friendCellWithTableView:(UITableView *)tableView;

@end