MJRefresh是很好用的一個(gè)刷新控件，但是如果在每個(gè)ViewController中都加入如下代碼
self.tableView.header = [MJRefreshNormalHeader headerWithRefreshingBlock:^{
//Call this Block When enter the refresh status automatically
}];
self.tableView.mj_footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
//Call this Block When enter the refresh status automatically
}];
代碼復(fù)用性不高，而且每個(gè)ViewController 在加載更多的時(shí)候還要管理Page
所以想一個(gè)辦法對(duì)MJRefresh進(jìn)行二次封裝，在使用的時(shí)候方便調(diào)用。
MJRefresh 支持TableView，CollectionView，Scrollview，很容易聯(lián)想到TableView，CollectionView都是繼續(xù)Scrollview，那我們寫一個(gè)Scrollview的Category是不是就可以
接下來我們需要考慮兩個(gè)問題，Category是不可以直接添加屬性的，那我們?cè)趺刺砑覲age和刷新Block這兩個(gè)屬性。相信都知道用RunTime 關(guān)聯(lián)屬性不就可以了。
所以我們?cè)贑ategory中聲明屬性
typedef void(^RefreshBlock)(NSInteger pageIndex);
typedef void(^LoadMoreBlock)(NSInteger pageIndex);
@interface UIScrollView()
/**頁碼*/
@property (assign, nonatomic) NSInteger pageIndex;
/**下拉時(shí)候觸發(fā)的block*/
@property (nonatomic, copy) RefreshBlock refreshBlock;
/**上拉時(shí)候觸發(fā)的block*/
@property (nonatomic, copy) LoadMoreBlock loadMoreBlock;
@end
然后用RunTime添加屬性
static void *pagaIndexKey = &pagaIndexKey;
- (void)setPageIndex:(NSInteger)pageIndex{
objc_setAssociatedObject(self, &pagaIndexKey, @(pageIndex), OBJC_ASSOCIATION_ASSIGN);
}
- (NSInteger)pageIndex
{
return [objc_getAssociatedObject(self, &pagaIndexKey) integerValue];
}
static void *RefreshBlockKey = &RefreshBlockKey;
- (void)setRefreshBlock:(void (^)(void))RefreshBlock{
objc_setAssociatedObject(self, &RefreshBlockKey, RefreshBlock, OBJC_ASSOCIATION_COPY);
}
- (RefreshBlock)refreshBlock
{
return objc_getAssociatedObject(self, &RefreshBlockKey);
}
static void *LoadMoreBlockKey = &LoadMoreBlockKey;
- (void)setLoadMoreBlock:(LoadMoreBlock)loadMoreBlock{
objc_setAssociatedObject(self, &LoadMoreBlockKey, loadMoreBlock, OBJC_ASSOCIATION_COPY);
}
- (LoadMoreBlock)loadMoreBlock
{
return objc_getAssociatedObject(self, &LoadMoreBlockKey);
}
接下來就是添加兩個(gè)刷新和加載更多的方法
- (void)addHeaderWithHeaderWithBeginRefresh:(BOOL)beginRefresh animation:(BOOL)animation refreshBlock:(void(^)(NSInteger pageIndex))refreshBlock{
__weak typeof(self) weakSelf = self;
self.refreshBlock = refreshBlock;
MJRefreshNormalHeader * header = [MJRefreshNormalHeader headerWithRefreshingBlock:^{
[weakSelf resetPageNum];
if (weakSelf.refreshBlock) {
weakSelf.refreshBlock(weakSelf.pageIndex);
}
[weakSelf endHeaderRefresh];
}];
if (beginRefresh && animation) {
//有動(dòng)畫的刷新
[self beginHeaderRefresh];
}else if (beginRefresh && !animation){
//刷新，但是沒有動(dòng)畫
[self.mj_header executeRefreshingCallback];
}
header.mj_h = 70.0;
self.mj_header = header;
}
- (void)addFooterWithWithHeaderWithAutomaticallyRefresh:(BOOL)automaticallyRefresh loadMoreBlock:(void(^)(NSInteger pageIndex))loadMoreBlock{
self.loadMoreBlock = loadMoreBlock;
if (automaticallyRefresh) {
MJRefreshAutoNormalFooter * footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
self.pageIndex += 1;
if (self.loadMoreBlock) {
self.loadMoreBlock(self.pageIndex);
}
// 如果需要設(shè)置MJRefreshStateNoMoreData，則需要注釋該方法，在請(qǐng)求數(shù)據(jù)回來的時(shí)候判斷是調(diào)用endFooterRefresh方法還是調(diào)用endFooterNoMoreData
[self endFooterRefresh];
}];
footer.automaticallyRefresh = automaticallyRefresh;
footer.stateLabel.font = [UIFont systemFontOfSize:13.0];
footer.stateLabel.textColor = [UIColor colorWithWhite:0.400 alpha:1.000];
[footer setTitle:@"加載中…" forState:MJRefreshStateRefreshing];
[footer setTitle:@"這是我的底線啦~" forState:MJRefreshStateNoMoreData];
self.mj_footer = footer;
}
else{
MJRefreshBackNormalFooter * footer = [MJRefreshBackNormalFooter footerWithRefreshingBlock:^{
self.pageIndex += 1;
if (self.loadMoreBlock) {
self.loadMoreBlock(self.pageIndex);
}
// 如果需要設(shè)置MJRefreshStateNoMoreData，則需要注釋該方法，在請(qǐng)求數(shù)據(jù)回來的時(shí)候判斷是調(diào)用endFooterRefresh方法還是調(diào)用endFooterNoMoreData
[self endFooterRefresh];
}];
footer.stateLabel.font = [UIFont systemFontOfSize:13.0];
footer.stateLabel.textColor = [UIColor colorWithWhite:0.400 alpha:1.000];
[footer setTitle:@"加載中…" forState:MJRefreshStateRefreshing];
[footer setTitle:@"這是我的底線啦~" forState:MJRefreshStateNoMoreData];
self.mj_footer = footer;
}
}
-(void)beginHeaderRefresh {
[self resetPageNum];
[self.mj_header beginRefreshing];
}
- (void)resetPageNum {
self.pageIndex = 0;
}
- (void)resetNoMoreData {
[self.mj_footer resetNoMoreData];
}
-(void)endHeaderRefresh {
[self.mj_header endRefreshing];
[self resetNoMoreData];
}
-(void)endFooterRefresh {
[self.mj_footer endRefreshing];
}
- (void)endFooterNoMoreData
{
dispatch_async(dispatch_get_main_queue(), ^{
[self.mj_footer endRefreshingWithNoMoreData];
});
}
調(diào)用,是不是很簡單，都不需要單獨(dú)管理Page
[self.tableView addHeaderWithHeaderWithBeginRefresh:YES animation:YES refreshBlock:^(NSInteger pageIndex) {
NSLog(@"pageIndex:%zd",pageIndex);
}];
[self.tableView addFooterWithWithHeaderWithAutomaticallyRefresh:NO loadMoreBlock:^(NSInteger pageIndex) {
NSLog(@"pageIndex:%zd",pageIndex);
}];
IOS書童提出了一個(gè)問題，我修改了源碼加上了如下方法
- (void)endFooterNoMoreData
{
dispatch_async(dispatch_get_main_queue(), ^{
[self.mj_footer endRefreshingWithNoMoreData];
});
}
如果要設(shè)置endRefreshingWithNoMoreData,則要注釋 [self endFooterRefresh]方法，改為根據(jù)請(qǐng)求返回?cái)?shù)據(jù)的時(shí)候判斷調(diào)用endFooterRefresh和endFooterNoMoreData方法。具體參考demo
MJRefreshAutoNormalFooter * footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
self.pageIndex += 1;
if (self.loadMoreBlock) {
self.loadMoreBlock(self.pageIndex);
}
// 如果需要設(shè)置MJRefreshStateNoMoreData，則需要注釋該方法，在請(qǐng)求數(shù)據(jù)回來的時(shí)候判斷是調(diào)用endFooterRefresh方法還是調(diào)用endFooterNoMoreData
[self endFooterRefresh];
}];
另外這個(gè)方案只是一個(gè)思路，并不是一個(gè)完整的考慮了很多實(shí)際場景的組件，如果不能滿足需求的自己修改代碼。
