iOS DataSource从tableview分离 简化viewController

通过分离dataSource 让我们的code具有更高的复用性.

转载自汪海的实验室

一 定义dataSource

dataSource.h

typedef void (^TableViewCellConfigureBlock)(id cell, id item);

@interface GroupNotificationDataSource : NSObject<UITableViewDataSource>

- (id)initWithItems:(NSArray *)anItems cellIdentifier:(NSString *)aCellIdentifier configureCellBlock:(TableViewCellConfigureBlock)aConfigureCellBlock;

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

@end

dataSource.m
@implementation GroupNotificationDataSource
{
NSArray *_itemsArray;
NSString *_cellIdentifier;
TableViewCellConfigureBlock _configureCellBlock;
}

- (id)init{
return nil;
}

- (id)initWithItems:(NSArray *)anItems cellIdentifier:(NSString *)aCellIdentifier configureCellBlock:(TableViewCellConfigureBlock)aConfigureCellBlock{
self = [super init];
if (self) {
_itemsArray = anItems;
_cellIdentifier = aCellIdentifier;
_configureCellBlock = [aConfigureCellBlock copy];
}
return self;
}

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

#pragma mark tableView DataSource
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return _itemsArray.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
// NOTE: This method can return nil so you need to account for that in code
GroupNotificationCell *cell=[tableView dequeueReusableCellWithIdentifier:_cellIdentifier];
// NOTE: Add some code like this to create a new cell if there are none to reuse
if (cell==nil) {
cell=[[GroupNotificationCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:_cellIdentifier];
}
id item = [self itemAtIndexPath:indexPath];
_configureCellBlock(cell, item);
return cell;
}

其中,需要注意tableView:cellForRowAtIndexPath:方法中对于cell的重用
二 重写cell的初始化

cell.h

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier;


cell.m
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{
self=[super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
[self configureUI];
}
return self;
}

三 controller中设置tableview的dataSource
_dataSource=[[GroupNotificationDataSource alloc]initWithItems:[NSArray arrayWithObjects:@"1",@"2", nil] cellIdentifier:CellIdentifier configureCellBlock:^(id cell, id item) {
//
}];
_tableview.dataSource=_dataSource;

需要注意的是_dataSource应该是成员变量,而非局部变量,否则会报错:message send to delloced object