UITableView - 2

来源：互联网发布：sql server复制表结构编辑：程序博客网时间：2024/05/22 01:58

4.折叠（像QQ联系人展开，收起的效果）:

实现方法一：

头文件：

#import <UIKit/UIKit.h>@interface ViewController : UIViewController@end#pragma mark - Customer TableViewHeaderFooterView@interface PressHeader : UITableViewHeaderFooterView@property (nonatomic, strong) UIButton* pressButton;- (instancetype)initWithFrame:(CGRect)frame           andReuseIdentifier:(NSString*)reuseIdentifier                    andTarget:(id)target andAction:(SEL)sel                       andTag:(NSInteger)tag andTitle:(NSString*)title;@end

实现文件：

ConstantHeader是这些内容：

#define FOLD_STATE @"FOLD_STATE"#define cellReuseIdentifier @"cellReuseIdentifier"#define headerReuseIdentifier @"headerReuseIdentifier"

#import "ConstantHeader.h"#import "ViewController.h"@interface ViewController () <UITableViewDataSource, UITableViewDelegate>{    UITableView* tableview;    NSMutableArray* dataArr;    }@end@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];        NSArray* arr = @[                     @{                         @"魏": @[                                 @"张辽",                                 @"李典",                                 @"曹洪"                                 ]                         },                     @{                         @"蜀": @[                                 @"关羽",                                 @"张飞",                                 @"赵云"                                 ]                         },                     @{                         @"吴": @[                                 @"周瑜",                                 @"鲁肃",                                 @"黄盖"                                 ]                         }                     ];        dataArr = [NSMutableArray array];        for (NSDictionary* dic in arr)    {        NSMutableDictionary* newDic = [dic mutableCopy];        [newDic setObject:[NSNumber numberWithBool:YES] forKey:FOLD_STATE];                [dataArr addObject:newDic];    }            tableview = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen] bounds]                                             style:UITableViewStylePlain];    tableview.delegate   = self;    tableview.dataSource = self;    [self.view addSubview:tableview];        UIView* footer = [[UIView alloc] initWithFrame:CGRectZero];    tableview.tableFooterView = footer;    }#pragma mark - Obtain Key- (NSString*)obtainKey:(NSDictionary* )dic{    NSString* key = NULL;    NSArray* tempArr = [dic allKeys];    for (NSString* str in tempArr)    {        if (![str isEqualToString:FOLD_STATE])        {            key = str;        }    }        return key;}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];}#pragma mark - UITableViewDelegate && UITableViewDataSource- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    NSDictionary* dic = [dataArr objectAtIndex:section];    if ([[dic objectForKey:FOLD_STATE] boolValue])    {        return 0;    }    NSString* key = NULL;    key = [self obtainKey:dic];        return [[dic objectForKey:key] count];}- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{    return [dataArr count];}- (UITableViewCell* )tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    UITableViewCell* cell = [tableview dequeueReusableCellWithIdentifier:cellReuseIdentifier];        if (!cell)    {        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault                                      reuseIdentifier:cellReuseIdentifier];    }        NSDictionary* dic = [dataArr objectAtIndex:indexPath.section];        NSString* key = NULL;    key = [self obtainKey:dic];        NSArray* cellDataArr = [dic objectForKey:key];    cell.textLabel.text = [cellDataArr objectAtIndex:indexPath.row];        return cell;}- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{    return 44.0;}-(UIView*)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{    NSDictionary* dic = [dataArr objectAtIndex:section];        NSString* key = NULL;    key = [self obtainKey:dic];            PressHeader* pressHedaer = nil;    pressHedaer = [tableView dequeueReusableHeaderFooterViewWithIdentifier:headerReuseIdentifier];        if (pressHedaer == nil)    {        pressHedaer = [[PressHeader alloc]                       initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, 44)                       andReuseIdentifier:headerReuseIdentifier                       andTarget:self                       andAction:@selector(press:)                       andTag:section+100                       andTitle:key];    }        return pressHedaer;}-(void)press:(UIButton*)btn{    NSMutableDictionary* dic = [dataArr objectAtIndex:btn.tag-100];    NSNumber* number = [dic objectForKey:FOLD_STATE];    if ([number boolValue])    {        [dic setObject:[NSNumber numberWithBool:NO] forKey:FOLD_STATE];    }    else    {        [dic setObject:[NSNumber numberWithBool:YES] forKey:FOLD_STATE];    }        //局部reload    [tableview reloadSections:[NSIndexSet indexSetWithIndex:btn.tag-100] withRowAnimation:UITableViewRowAnimationFade];}@end#pragma mark - Customer TableViewHeaderFooterView@implementation PressHeader- (instancetype)initWithFrame:(CGRect)frame           andReuseIdentifier:(NSString *)reuseIdentifier                    andTarget:(id)target andAction:(SEL)sel                       andTag:(NSInteger)tag andTitle:(NSString *)title{    self = [super initWithReuseIdentifier:reuseIdentifier];        if (self)    {        self.frame = frame;                self.pressButton = [UIButton buttonWithType:UIButtonTypeCustom];        [self.pressButton setFrame:frame];        [self.pressButton setBackgroundColor:[UIColor grayColor]];        [self.pressButton setTitle:title                          forState:UIControlStateNormal];                [self.pressButton addTarget:target                             action:sel                   forControlEvents:UIControlEventTouchUpInside];        [self.pressButton setTag:tag];                [self.contentView addSubview:self.pressButton];    }        return self;}@end

这个实现方法很简单，就是把每一个viewheader都放置一个button，然后根据状态的值来决定是否展开。

优点：简单，每一个header都能重用

注意：这个方法的本质是对数据结构的灵活运用，首先是对数据的封装，设置了一个BOOL的判断值。这个例子的不足，没有考虑如果值为空的情况，例如“越国”没有人才，这个时候会怎么样？字典数据应该怎么处理？

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