打造轻量级ViewController之用Block分离TableView的dataSource

各位大侠在开发的过程中可能会有这样的困惑:每次编写tableview的代码都要写那几个方法,而且必备的方法一个不能少,而这些代码往往会使得我们的ViewController类看起来很复杂,那么有没有什么办法把tableview的这些必备方法分离开来呢.答案是肯定的,下面我们就来探讨下用Block来分离tableview的dataSource

设计的思路是将tableview的dataSource 放在一个单独的类中,这个类实现tableView的dataSource协议,然后在ViewController里面使用的时候实例化这个类,然后赋给tableview的dataSource.如果你多次尝试这样的设计,也许你会发现如何设计一个可以复用的tableview的dataSource类.下面我们看码:

首先声明一个DataSource类如下:

#import <Foundation/Foundation.h>
typedef void(^TableViewCellConfigureBlock) (id cell,id item);
@interface LYHArrayDataSource : NSObject<UITableViewDataSource>

-(id)initWithItems:(NSArray *)anItems cellItentifier:(NSString *)aCellIdentifier configureCellBlock:(TableViewCellConfigureBlock)aConofigureCellBlock;

- (id)itemAtIndexPath:(NSIndexPath *)indexPath;

@end

实现部分:

#import "LYHArrayDataSource.h"
#import "LYHDataCell.h"
@interface LYHArrayDataSource()
@property (nonatomic, strong) NSArray *items;
@property (nonatomic, copy) NSString *cellIdentifier;
@property (nonatomic, copy) TableViewCellConfigureBlock configureCellBlock;

@end
@implementation LYHArrayDataSource

- (id)init
{
return nil;
}
-(id)initWithItems:(NSArray *)anItems cellItentifier:(NSString *)aCellIdentifier configureCellBlock:(TableViewCellConfigureBlock)aConofigureCellBlock
{
self = [super init];
if (self) {
self.items = anItems;
self.cellIdentifier = aCellIdentifier;
self.configureCellBlock = [aConofigureCellBlock copy];
}
return self;
}

-(id)itemAtIndexPath:(NSIndexPath *)indexPath
{
return self.items[(NSUInteger)indexPath.row];
}

#pragma mark UITableViewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.items.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
LYHDataCell * cell = [tableView dequeueReusableCellWithIdentifier:self.cellIdentifier];
if (cell== nil) {
cell = [[LYHDataCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:self.cellIdentifier];
}
id item = [self itemAtIndexPath:indexPath];
self.configureCellBlock(cell,item);
return cell;
}
@end
接下来我们看下我们自定义的tableViewCell:

#import <UIKit/UIKit.h>

@interface LYHDataCell : UITableViewCell
- (void)configureForData:(NSString *)data;
@end

实现部分:

#import "LYHDataCell.h"
@interface LYHDataCell()
@property (retain,nonatomic) UILabel * mTitle;

@end
@implementation LYHDataCell

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {

self.mTitle = [[UILabel alloc]initWithFrame:CGRectMake(30, 10, 200, 40)];
[self.contentView addSubview:self.mTitle];
}
return self;
}
- (void)configureForData:(NSString *)data
{
self.mTitle.text = data;
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];

// Configure the view for the selected state
}
现在呢,我们就可以看看如何在ViewController里面如何使用这个类:

#import <UIKit/UIKit.h>

@interface LYHTableViewController : UIViewController<UITableViewDelegate>
@property (strong,nonatomic) UITableView * mTableView;
@property (strong,nonatomic) NSArray * mArrayData;
@end

实现部分:

#import "LYHTableViewController.h"
#import "LYHArrayDataSource.h"
#import "LYHDataCell.h"
@interface LYHTableViewController ()
{
LYHArrayDataSource * _dataSource;
}
@end

@implementation LYHTableViewController
@synthesize mArrayData;
@synthesize mTableView;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];
NSArray * array = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10"];
self.mArrayData = array;
[self setUpTableView];
}
- (void)setUpTableView
{
UITableView * tableView = [[UITableView alloc]initWithFrame:self.view.bounds style:UITableViewStylePlain];
self.mTableView = tableView;

TableViewCellConfigureBlock configureBlock = ^(LYHDataCell *cell,NSString * titile){
[cell configureForData:titile];
};
_dataSource = [[LYHArrayDataSource alloc]initWithItems:self.mArrayData cellItentifier:@"ID" configureCellBlock:configureBlock];
self.mTableView.dataSource = _dataSource;

[self.view addSubview:self.mTableView];

}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 60;
}