我在网络数据库中有2000个位置,用户应该可以在地图上选择这些位置.我可以要求网络数据库只给我一些来自当前位置的位置.
为了使一切顺利和优雅,我首先实例化MKMapView,启动CLLocationManager并等到我得到didUpdateLocations.然后我会尝试从具有完成处理程序的数据库中获取数据.
我是不是该
a)立即获取所有数据
b)以小块或块的形式获取数据?
它最好的方式是什么?
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
self.gotoCurrentLocation()
if let userLocation = manager.location {
GroundHelper.getAllGroundLocations(userLocation) { self.handleWaypoints($0!) }
}
}
private func handleWaypoints(grounds: [Ground]) {
mapView.addAnnotations(grounds)
}
// MARK: - Helper Methods
typealias GPXCompletionHandler = ([Ground]?) -> Void
class func getAllGroundLocations(userlocation: CLLocation, completionHandler: GPXCompletionHandler) {
let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
dispatch_async(dispatch_get_global_queue(priority, 0), { ()->() in
var results = RestApiManager.sharedInstance.getGPS(userlocation, limit: 50)
// return first 50 results
dispatch_async(dispatch_get_main_queue(), {
var grounds = [Ground]()
for result in …
Run Code Online (Sandbox Code Playgroud) 使用Xcode 6.3 Beta 2和单元测试我有以下问题:
当我进行单元测试时,单元测试模块中的断点可以工作,但是不会忽略被测代码中的中断代码.
有任何想法吗?
在 ios/android 应用程序中,表情符号可以正确显示。但使用任何网络浏览器(例如 Chrome),表情符号都会以黑白显示。我也尝试了不同的字体系列,但结果相同。
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return const Scaffold(
body: Center(
child: Text('Enjoy! If there\'s any question')
),
);
}
}
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当我使用Predicate过滤自定义Swift类的数组时,我得到错误:
***NSForwarding:警告:类'Plantivo1_6.Seed'的对象0x78ed21a0没有实现methodSignatureForSelector: - 提前故障
无法识别的选择器 - [Plantivo1_6.Seed valueForKey:]
如果我没记错的话,这可以在Objective-C中使用.我的错是什么?
let names = ["Tom","Mike","Marc"]
println(names)
let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", "om")
let array = (names as NSArray).filteredArrayUsingPredicate(searchPredicate)
println(array)
println()
let mySeed1 = Seed() // Seed is a class with a `culture` String property
let mySeed2 = Seed()
let mySeed3 = Seed()
mySeed1.culture = "Tom"
mySeed2.culture = "Mike"
mySeed3.culture = "Marc"
let mySeeds = [mySeed1,mySeed2,mySeed3]
println(mySeeds)
let searchPredicate1 = NSPredicate(format: "SELF.culture CONTAINS[c] %@", "om")
let array1 = (mySeeds as NSArray).filteredArrayUsingPredicate(searchPredicate1) …
Run Code Online (Sandbox Code Playgroud) 这就是我嵌入视频的方式.它在模拟器中有声音,但在真实设备上没有声音(iOS 9.0.2(13A452))Xcode 7.1.1.
这是我用来播放它的代码:
if let youtubeID = youtubeID {
let embededHTML = "<html><body><iframe src=\"http://www.youtube.com/embed/\(youtubeID)?playsinline=1\" width=\"\(width)\" height=\"\(height)\" frameborder=\"0\" allowfullscreen></iframe></body></html>"
cell!.webView.allowsInlineMediaPlayback = true
cell!.webView.scalesPageToFit = true
cell!.webView.mediaPlaybackAllowsAirPlay = true
cell!.webView.mediaPlaybackRequiresUserAction = false
cell!.webView.loadHTMLString(embededHTML, baseURL: NSBundle.mainBundle().bundleURL)
}
Run Code Online (Sandbox Code Playgroud) 我有一个带有阴影的单元格的 UITableView。当我上下滚动时,单元格的阴影消失了。因为我认为这是一个重用问题,我已经只使用过这个带有阴影的单元格。这里可能有什么问题?
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = UITableViewCell()
switch indexPath.row {
case 3: cell = shadowBasicCellAtIndexPath(indexPath)
case 4: cell = contentCellAtIndexPath(indexPath)
case 5: cell = contentCellAtIndexPath(indexPath)
case 6: cell = contentCellAtIndexPath(indexPath)
case 11: cell = contentCellAtIndexPath(indexPath)
default: cell = basicCellAtIndexPath(indexPath)
}
return cell
}
func contentCellAtIndexPath(indexPath: NSIndexPath) -> ContentCell {
let cell = tableView.dequeueReusableCellWithIdentifier(contentCellIdentifier) as! ContentCell
setTitleForCell(cell, indexPath: indexPath)
setContentForCell(cell, indexPath: indexPath)
return cell
}
func shadowBasicCellAtIndexPath(indexPath: NSIndexPath) -> ShadowBasicCell {
// let …
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