使用异步数据更新TableViewCell
使用异步数据更新TableViewCell
提问于 2015-12-28 03:06:38
我有一个包含8个图像的tableViewCell，分为两个块(每个块4个图像)。这些图像被异步下载并存储到一个数组中，然后在tableViewCell的cellForRowAtIndexPath中用来填充图像。当一个块的所有图像都添加到字典中的数组中时(groupTOImages)，我重新加载tableView。在我这样做的方式下，我得到了与数据加载不一致的结果。有些图像会被加载到不应该出现的地方。有没有办法下载图像并在tableViewCell中获得一致的结果。
var groupNames = [NSManagedObject]()
var groupTOPeople = [NSManagedObject: [String]]()
var groupTOImages = [NSManagedObject: [UIImage]]()
func getGroups() {
...
for group in groupNames {
groupTOImages[group] = []
if let people = groupTOPeople[group] {
var mycount = 0
for peeps in people {
InstagramEngine.sharedEngine().getUserDetails(peeps, withSuccess: { user in
if let ppic = user.profilePictureURL {
let picUrl = ppic.absoluteString
print(picUrl)
ImageLoader.sharedLoader.imageForUrl(picUrl) { (image, url) -> () in
self.groupTOImages[group]?.append(image!)
mycount++
if mycount == people.count {
self.tableView.reloadData()
}
}
} else {
self.groupTOImages[group]?.append(UIImage())
mycount++
if mycount == people.count {
self.tableView.reloadData()
}
}
}, failure: nil )
}
}
}
var counter = 0
var groupCount = 0
var groupCounter = 0
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellInfo = GroupCellsArray[indexPath.section]
...
case .userGroups:
let cell = tableView.dequeueReusableCellWithIdentifier(cellInfo.description, forIndexPath: indexPath) as! GroupTableViewCell
if groupNames.count > 0 {
var gp = groupNames[groupCounter]
switch counter {
case 0:
cell.firstTitle.text = (gp.valueForKey("name") as! String)
if let ourImages = groupTOImages[gp] {
for image in ourImages {
print(image.description)
print("groupCount \(groupCounter)")
cell.firstUserButtons[groupCount].layer.borderWidth = 0
cell.firstUserButtons[groupCount].setImage(image, forState: .Normal)
groupCount++
if groupCount == ourImages.count {
groupCount = 0
counter++
groupCounter++
gp = groupNames[groupCounter]
}
}
}
case 1:
if let title = gp.valueForKey("name") as? String {
cell.secondTitle.text = title
if let ourImages = groupTOImages[gp] {
for image in ourImages {
cell.secondUserButtons[groupCount].layer.borderWidth = 0
cell.secondUserButtons[groupCount].setImage(image, forState: .Normal)
groupCount++
if groupCount == ourImages.count {
groupCount = 0
counter = 0
groupCounter++
gp = groupNames[groupCounter]
}
}
}
} else {
cell.secondTitle.text = "Title"
}
default:
break
}每一行如下图所示：
在cellForRowAtIndexPath中使用ImageLoader的代码：
var counter = 0
for group in groupNames {
print("in the second")
groupTOImages[group] = []
if let people = groupTOPeople[group] {
var mycount = 0
for peeps in people {
InstagramEngine.sharedEngine().getUserDetails(peeps, withSuccess: { user in
if let ppic = user.profilePictureURL {
let picUrl = ppic.absoluteString
self.groupTOImages[group]?.append(picUrl)
counter++
mycount++
if counter == self.groupNames.count && mycount == people.count
{
dispatch_async(dispatch_get_main_queue()) {
self.tableView.reloadData()
}
}
} else {
self.groupTOImages[group]?.append(nil)
counter++
mycount++
if counter == self.groupNames.count && mycount == people.count
{
dispatch_async(dispatch_get_main_queue()) {
self.tableView.reloadData()
}
}
}
}, failure: nil )
}
}
if groupNames.count > 0 {
var gp = groupNames[groupCounter]
print("counter!!!!")
print("groupCount \(counter)")
switch counter {
case 0:
if let ourImages = groupTOImages[gp] {
cell.firstTitle.text = (gp.valueForKey("name") as! String)
print(cell.firstTitle.text)
for image in ourImages {
if let url = image {
print("I get in here")
ImageLoader.sharedLoader.imageForUrl(url) { (image, url) -> () in
cell.firstUserButtons[self.groupCount].layer.borderWidth = 0
cell.firstUserButtons[self.groupCount].setImage(image, forState: .Normal)
self.groupCount++
if self.groupCount == ourImages.count {
self.groupCount = 0
self.counter++
self.groupCounter++
gp = self.groupNames[self.groupCounter]
}
}
} else {
self.groupCount++
if self.groupCount == ourImages.count {
self.groupCount = 0
self.counter++
self.groupCounter++
gp = self.groupNames[self.groupCounter]
}
}
}
}
case 1:
if let title = gp.valueForKey("name") as? String {
cell.secondTitle.text = title
if let ourImages = groupTOImages[gp] {
for image in ourImages {
if let url = image {
ImageLoader.sharedLoader.imageForUrl(url) { (image, url) -> () in
cell.secondUserButtons[self.groupCount].layer.borderWidth = 0
cell.secondUserButtons[self.groupCount].setImage(image, forState: .Normal)
self.groupCount++
if self.groupCount == ourImages.count {
self.groupCount = 0
self.counter++
self.groupCounter++
gp = self.groupNames[self.groupCounter]
}
}
} else {
self.groupCount++
if self.groupCount == ourImages.count {
self.groupCount = 0
self.counter = 0
self.groupCounter++
gp = self.groupNames[self.groupCounter]
}
}
}
}
} else {
cell.secondTitle.text = "Title"
}回答 1
Stack Overflow用户
发布于 2015-12-28 03:56:01
您应该将self.tableView.reloadData()替换为
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.tableView.reloadData()
})希望这能有所帮助！
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/34487213
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