Ios-tableview Drag Cell Change Order

Effect:

Long pressing a cell,cell will have an obvious bounce-up effect. At this point, you can change the order by dragging the cell and other cells.

The principle of implementation:

1, floating layer

When you press and hold, a floating layer appears on the UITableViewCell, while the UITableViewCell is hidden. And the floating layer can be dragged. (Generate a snapshot of UITableViewCell)

1 #pragmaMark-helper methods2 3 /** @brief Returns A customized snapshot of a given view.*/4-(UIView *) Customsnapshofromview: (UIView *) Inputview {5uiview* snapshot =Nil;6     7     if([[[[Uidevice Currentdevice] systemversion] Doublevalue] <7.0) {8         //ios7.0 The following form to save the snapshot9snapshot =[self customsnapshortfromviewex:inputview];Ten}Else{ One         //snapshot methods for ios7.0 systems Asnapshot =[Inputview Snapshotviewafterscreenupdates:yes]; -     } -      theSnapshot.layer.masksToBounds =NO; -Snapshot.layer.cornerRadius =0.0; -Snapshot.layer.shadowOffset = Cgsizemake (-5.0,0.0); -Snapshot.layer.shadowRadius =5.0; +Snapshot.layer.shadowOpacity =0.4; -      +     returnsnapshot; A } at  --(UIView *) Customsnapshortfromviewex: (UIView *) Inputview - { -Cgsize insize =inputView.bounds.size; -     //The following method, the first parameter represents the size of the area. The second parameter indicates whether it is non-transparent. If you need to display a translucent effect, you need to pass no, otherwise pass yes. The third parameter is the screen density. - uigraphicsbeginimagecontextwithoptions (Insize, NO, [UIScreen mainscreen].scale); in [Inputview.layer Renderincontext:uigraphicsgetcurrentcontext ()]; -UIImage *image=Uigraphicsgetimagefromcurrentimagecontext (); to Uigraphicsendimagecontext (); +uiimageview* snapshot =[[Uiimageview alloc] initwithimage:image]; -      the     returnsnapshot; *}

2, replace the position of a UITableViewCell

?

1 2 3 4

// ... update data source. [_items exchangeObjectAtIndex:indexPath.row withObjectAtIndex:sourceIndexPath.row];              // ... move the rows.[_tableView moveRowAtIndexPath:sourceIndexPath toIndexPath:indexPath];

The location of the data inside the datasource is replaced, and the cell location of the TableView is replaced.

1- (void) Longpressgesturerecognized: (ID) Sender {2     3Uilongpressgesturerecognizer *longpress = (Uilongpressgesturerecognizer *) sender;4Uigesturerecognizerstate State =longpress.state;5     6Cgpoint location =[longpress Locationinview:_tableview];7Nsindexpath *indexpath =[_tableview indexpathforrowatpoint:location];8     9     StaticUIView *snapshot = nil;///< A snapshot of the row user is moving.Ten static Nsindexpath *sourceindexpath = nil;///< Initial index path, where gesture begins. One      A     Switch(state) { -          CaseUigesturerecognizerstatebegan: { -             if(Indexpath) { theSourceindexpath =Indexpath; -                  -UITableViewCell *cell =[_tableview Cellforrowatindexpath:indexpath]; -                  +                 //Take a snapshot of the selected row using helper method. -snapshot =[self Customsnapshofromview:cell]; +                  A                 //Add the snapshot as Subview, centered at cell ' s center ... at__block Cgpoint Center =Cell.center; -Snapshot.center =Center; -Snapshot.alpha =0.0; - [_tableview addsubview:snapshot]; -[UIView animatewithduration:0.25animations:^{ -                      in                     //Offset for gesture location. -CENTER.Y =LOCATION.Y; toSnapshot.center =Center; +Snapshot.transform = Cgaffinetransformmakescale (1.05,1.05); -Snapshot.alpha =0.98; the                      *Cell.alpha =0.0f; $} completion:^(BOOL finished) {Panax NotoginsengCell.hidden =YES; -                 }]; the             } +              Break; A         } the              +          Caseuigesturerecognizerstatechanged: { -Cgpoint Center =Snapshot.center; $CENTER.Y =LOCATION.Y; $Snapshot.center =Center; -              -             //is destination valid and was it different from source? the             if(Indexpath &&!)[Indexpath Isequal:sourceindexpath]) { -                 Wuyi                 //... update data source. the [_items exchangeObjectAtIndex:indexPath.row withObjectAtIndex:sourceIndexPath.row]; -                  Wu                 //... move the rows. - [_tableview Moverowatindexpath:sourceindexpath Toindexpath:indexpath]; About                  $                 //... and update source so it's in sync with UI changes. -Sourceindexpath =Indexpath; -             } -              Break; A         } +              the         default: { -             //Clean up . $UITableViewCell *cell =[_tableview Cellforrowatindexpath:sourceindexpath]; the[UIView animatewithduration:0.25animations:^{ the                  theSnapshot.center =Cell.center; theSnapshot.transform =cgaffinetransformidentity; -Snapshot.alpha =0.0; in                  theCell.alpha =1.0f; the} completion:^(BOOL finished) { AboutCell.hidden =NO; the [Snapshot Removefromsuperview]; thesnapshot =Nil; the                  +             }]; -Sourceindexpath =Nil; the              Break;Bayi         } the     } the}

3, ... Does it seem like there's nothing else?

You see, isn't it simple! With just a few lines of code above, you can achieve a slightly better-looking UITableViewCell transform position.

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