我在storyBoard中有一个tableView,我在其中添加了4个静态单元格,我的storyBoard看起来像：
我没有这个tableView的任何dataSource,因为我的单元格是静态的.
我使用下面的代码拖动一个单元格,它工作正常,直到我滚动一个表格.
import UIKit
class TableViewController: UITableViewController {
var sourceIndexPath: NSIndexPath = NSIndexPath()
var snapshot: UIView = UIView()
let longPress: UILongPressGestureRecognizer = {
let recognizer = UILongPressGestureRecognizer()
return recognizer
}()
override func viewDidLoad() {
super.viewDidLoad()
longPress.addTarget(self,action: "longPressGestureRecognized:")
self.tableView.addGestureRecognizer(longPress)
self.tableView.allowsSelection = false
}
override func viewWillAppear(animated: Bool) {
self.tableView.reloadData()
}
// MARK: UIGestureRecognizer
func longPressGestureRecognized(gesture: UILongPressGestureRecognizer){
let state: UIGestureRecognizerState = gesture.state
let location:CGPoint = gesture.locationInView(self.tableView)
if let indexPath: NSIndexPath = self.tableView.indexPathForRowAtPoint(location){
switch(state){
case UIGestureRecognizerState.Began:
sourceIndexPath = indexPath
let cell: UITableViewCell = self.tableView .cellForRowAtIndexPath(indexPath)!
//take a snapshot of the selected row using helper method
snapshot = customSnapshotFromView(cell)
//add snapshot as subview,centered at cell's center
var center: CGPoint = cell.center
snapshot.center = center
snapshot.alpha = 0.0
self.tableView.addSubview(snapshot)
UIView.animateWithDuration(0.25,animations: { () -> Void in
center.y = location.y
self.snapshot.center = center
self.snapshot.transform = CGAffineTransformMakeScale(1.05,1.05)
self.snapshot.alpha = 0.98
cell.alpha = 0.0
},completion: { (finished) in
cell.hidden = true
})
case UIGestureRecognizerState.Changed:
let cell: UITableViewCell = self.tableView.cellForRowAtIndexPath(indexPath)!
var center: CGPoint = snapshot.center
center.y = location.y
snapshot.center = center
print("location \(location.y)")
//is destination valid and is it different form source?
if indexPath != sourceIndexPath{
//update data source
//I have commented this part because I am not using any dataSource.
// self.customArray.exchangeObjectAtIndex(indexPath.row,withObjectAtIndex: sourceIndexPath.row)
//move the row
self.tableView.moveRowAtIndexPath(sourceIndexPath,toIndexPath: indexPath)
//and update source so it is in sync with UI changes
sourceIndexPath = indexPath
}
if (location.y < 68) || (location.y > 450) {
print("cancelled")
self.snapshot.alpha = 0.0
cell.hidden = false
UIView.animateWithDuration(0.10,animations: { () -> Void in
self.snapshot.center = cell.center
self.snapshot.transform = CGAffineTransformIdentity
self.snapshot.alpha = 0.0
//undo fade out
cell.alpha = 1.0
},completion: { (finished) in
self.snapshot.removeFromSuperview()
})
}
case UIGestureRecognizerState.Ended:
//clean up
print("ended")
let cell: UITableViewCell = tableView.cellForRowAtIndexPath(indexPath)!
cell.hidden = false
UIView.animateWithDuration(0.25,animations: { () -> Void in
self.snapshot.center = cell.center
self.snapshot.transform = CGAffineTransformIdentity
self.snapshot.alpha = 0.0
//undo fade out
cell.alpha = 1.0
},completion: { (finished) in
self.snapshot.removeFromSuperview()
})
break
default:
break
}
}else{
gesture.cancelsTouchesInView = true
}
}
func customSnapshotFromView(inputView: UIView) -> UIView {
// Make an image from the input view.
UIGraphicsBeginImageContextWithOptions(inputView.bounds.size,false,0)
inputView.layer.renderInContext(UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
// Create an image view.
let snapshot = UIImageView(image: image)
snapshot.layer.masksToBounds = false
snapshot.layer.cornerRadius = 0.0
snapshot.layer.shadowOffset = CGSize(width: -5.0,height: 0.0)
snapshot.layer.shadowRadius = 5.0
snapshot.layer.shadowOpacity = 0.4
return snapshot
}
}
拖动后滚动它看起来像：
正如你所看到的那样,细胞不再出现了.我想拖放静态单元格,我想保存它的位置,所以当我滚动时我不会再重新排列.
Sample项目了解更多信息.
这只是一个演示项目但我在我的单元格中添加了许多元素,每个单元格都有不同的UI.
解决方法
有一个库可以使用非常类似的方法完成您正在寻找的工作.它被称为
FMMoveTableView,但它适用于具有数据源的单元.
我认为造成问题的原因是,当您移动单元格然后从故事板滚动数据源时,不再与表格同步,因此无法重绘单元格对象.
我认为你应该这样实现你的表：
>制作4个单元格自定义单元格.>每个子类.>创建一个数字为1到4的数组>在长拖动时重新排序数组>覆盖cellForRowAtIndexPath以显示正确数字的正确单元格
