Table View 和Collection View的使用
TableView是iOS開發(fā)中經常用到的一個組件，其重要程度可想而知。
Collection View提供了比Table View更多的空間來顯示更多的內容。
數據源
顧名思義，為table view和 collection view提供數據的來源。
UITableViewDataSource
在以下的函數中可以實現對table view的數據來源的配置
/*配置table view*/
@ Required
//返回指定位置的table cell
- tableView:cellForRowAtIndexPath:
@ Required
//返回各個區(qū)中有多少行
- tableView:numberOfRowsInSection:
//返回這個table view中包含了多少個分區(qū)section
- numberOfSectionsInTableView:
//返回每個section的標題
- sectionIndexTitlesForTableView:
//返回有標題和分區(qū)標題索引的index
- tableView:sectionForSectionIndexTitle:atIndex:
//返回一個字符串來作為分區(qū)header的標題
- tableView:titleForHeaderInSection:
//返回一個字符串來作為分區(qū)footer的標題
- tableView:titleForFooterInSection:
/*插入和刪除row*/
//對一個特定的row來進行刪除或者插入操作
- tableView:commitEditingStyle:forRowAtIndexPath:
//返回一個布爾值來表示這行row是否可以被編輯
- tableView:canEditRowAtIndexPath:
/*對rows重新排序*/
//返回一個布爾值表示這行row是否可以被移動
- tableView:canMoveRowAtIndexPath:
//在這個方法里可以對特定的row進行移動
- tableView:moveRowAtIndexPath:toIndexPath:
UITableViewDelegate
通過該協議，可以對tableview的點擊事件進行響應及對tableview進行配置。
// 顯示定制
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath;
- (void)tableView:(UITableView *)tableView willDisplayHeaderView:(UIView *)view forSection:(NSInteger)section NS_AVAILABLE_IOS(6_0);
- (void)tableView:(UITableView *)tableView willDisplayFooterView:(UIView *)view forSection:(NSInteger)section NS_AVAILABLE_IOS(6_0);
- (void)tableView:(UITableView *)tableView didEndDisplayingCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath*)indexPath NS_AVAILABLE_IOS(6_0);
- (void)tableView:(UITableView *)tableView didEndDisplayingHeaderView:(UIView *)view forSection:(NSInteger)section NS_AVAILABLE_IOS(6_0);
- (void)tableView:(UITableView *)tableView didEndDisplayingFooterView:(UIView *)view forSection:(NSInteger)section NS_AVAILABLE_IOS(6_0);
//可變的高度的支持
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section;
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section;
// Use the estimatedHeight methods to quickly calcuate guessed values which will allow for fast load times of the table.
// If these methods are implemented, the above -tableView:heightForXXX calls will be deferred until views are ready to be displayed, so more expensive logic can be placed there.
- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(7_0);
- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForHeaderInSection:(NSInteger)section NS_AVAILABLE_IOS(7_0);
- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForFooterInSection:(NSInteger)section NS_AVAILABLE_IOS(7_0);
// 分區(qū)的header和footer信息，
- (nullable UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section; // custom view for header. will be adjusted to default or specified header height
- (nullable UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section; // custom view for footer. will be adjusted to default or specified footer height
// 選中的事件
// -tableView:shouldHighlightRowAtIndexPath: 當按下row的時候被執(zhí)行
// 停止選中的過程會返回 NO， 不會讓已選中的失去被選中的狀態(tài)
- (BOOL)tableView:(UITableView *)tableView shouldHighlightRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(6_0);
- (void)tableView:(UITableView *)tableView didHighlightRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(6_0);
- (void)tableView:(UITableView *)tableView didUnhighlightRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(6_0);
// Called before the user changes the selection. Return a new indexPath, or nil, to change the proposed selection.
- (nullable NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath;
- (nullable NSIndexPath *)tableView:(UITableView *)tableView willDeselectRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(3_0);
// Called after the user changes the selection.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;
- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(3_0);
// 編輯
// Allows customization of the editingStyle for a particular cell located at 'indexPath'. If not implemented, all editable cells will have UITableViewCellEditingStyleDelete set for them when the table has editing property set to YES.
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath;
- (nullable NSString *)tableView:(UITableView *)tableView titleForDeleteConfirmationButtonForRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(3_0) __TVOS_PROHIBITED;
- (nullable NSArray<UITableViewRowAction *> *)tableView:(UITableView *)tableView editActionsForRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(8_0) __TVOS_PROHIBITED; // supercedes -tableView:titleForDeleteConfirmationButtonForRowAtIndexPath: if return value is non-nil
// Controls whether the background is indented while editing. If not implemented, the default is YES. This is unrelated to the indentation level below. This method only applies to grouped style table views.
- (BOOL)tableView:(UITableView *)tableView shouldIndentWhileEditingRowAtIndexPath:(NSIndexPath *)indexPath;
// The willBegin/didEnd methods are called whenever the 'editing' property is automatically changed by the table (allowing insert/delete/move). This is done by a swipe activating a single row
- (void)tableView:(UITableView*)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath __TVOS_PROHIBITED;
- (void)tableView:(UITableView*)tableView didEndEditingRowAtIndexPath:(NSIndexPath *)indexPath __TVOS_PROHIBITED;
// Moving/reordering
// Allows customization of the target row for a particular row as it is being moved/reordered
- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath;
// Indentation
- (NSInteger)tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath; // return 'depth' of row for hierarchies
// Copy/Paste. All three methods must be implemented by the delegate.
- (BOOL)tableView:(UITableView *)tableView shouldShowMenuForRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(5_0);
- (BOOL)tableView:(UITableView *)tableView canPerformAction:(SEL)action forRowAtIndexPath:(NSIndexPath *)indexPath withSender:(nullable id)sender NS_AVAILABLE_IOS(5_0);
- (void)tableView:(UITableView *)tableView performAction:(SEL)action forRowAtIndexPath:(NSIndexPath *)indexPath withSender:(nullable id)sender NS_AVAILABLE_IOS(5_0);
// Focus
- (BOOL)tableView:(UITableView *)tableView canFocusRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(9_0);
- (BOOL)tableView:(UITableView *)tableView shouldUpdateFocusInContext:(UITableViewFocusUpdateContext *)context NS_AVAILABLE_IOS(9_0);
- (void)tableView:(UITableView *)tableView didUpdateFocusInContext:(UITableViewFocusUpdateContext *)context withAnimationCoordinator:(UIFocusAnimationCoordinator *)coordinator NS_AVAILABLE_IOS(9_0);
- (nullable NSIndexPath *)indexPathForPreferredFocusedViewInTableView:(UITableView *)tableView NS_AVAILABLE_IOS(9_0);
UICollectionViewDataSource
Collectionview的使用和Tableview的使用非常類似。常用的數據源配置有如下方法：
@required
//返回每個section中的item的數量
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section;
// 返回的cell必須從以下的方法取得 -dequeueReusableCellWithReuseIdentifier:forIndexPath:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath;
@optional
//分區(qū)的數量
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView;
// 返回的view必須從以下的方法取得 -dequeueReusableSupplementaryViewOfKind:withReuseIdentifier:forIndexPath:
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath;
//返回item是否可以被移動
- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(9_0);
//移動item
- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath NS_AVAILABLE_IOS(9_0);
UICollectionViewDelegate
// 選中的方法
// 用戶touch之后的方法調用順序:
//
// (touch開始的時候)
// 1. -collectionView:shouldHighlightItemAtIndexPath:
// 2. -collectionView:didHighlightItemAtIndexPath:
//
// (touch離開的時候)
// 3. -collectionView:shouldSelectItemAtIndexPath: or -collectionView:shouldDeselectItemAtIndexPath:
// 4. -collectionView:didSelectItemAtIndexPath: or -collectionView:didDeselectItemAtIndexPath:
// 5. -collectionView:didUnhighlightItemAtIndexPath:
- (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath;
- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath;
- (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIndexPath:(NSIndexPath *)indexPath;
- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath;
- (BOOL)collectionView:(UICollectionView *)collectionView shouldDeselectItemAtIndexPath:(NSIndexPath *)indexPath; // called when the user taps on an already-selected item in multi-select mode
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath;
- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath;
對Tableview和Collectionview的使用主要就是這兩個協議，一個負責數據來源，一個負責處理和用戶的交互。使用方法也非常類似。
