如何在xamarin ios中上传和下载文件到iCloud

Question

我想将文档上传到iCloud。还需要从iCloud下载并编辑。我是xamarin ios应用程序的新手。找不到详细的例子。请帮忙。

Answer 1

使用iCloud文档存储的第一步是确定是否启用了iCloud，如果启用了，则确定"无处不在的容器"(设备上存储已启用iCloud的文件的目录(的位置。

此代码位于AppDelegate中。完成样品的发射方法。

ThreadPool.QueueUserWorkItem (_ => {
CheckingForiCloud = true;
Console.WriteLine ("Checking for iCloud");
var uburl = NSFileManager.DefaultManager.GetUrlForUbiquityContainer (null);
// OR instead of null you can specify "TEAMID.com.your-company.ApplicationName"
if (uburl == null) {
HasiCloud = false;
Console.WriteLine ("Can't find iCloud container, check your provisioning profile and entitlements");
InvokeOnMainThread (() => {
var alertController = UIAlertController.Create ("No uE049 available",
"Check your Entitlements.plist, BundleId, TeamId and Provisioning Profile!", UIAlertControllerStyle.Alert);
alertController.AddAction (UIAlertAction.Create ("OK", UIAlertActionStyle.Destructive, null));
viewController.PresentViewController (alertController, false, null);
});
} else { // iCloud enabled, store the NSURL for later use
HasiCloud = true;
iCloudUrl = uburl;
Console.WriteLine ("yyy Yes iCloud! {0}", uburl.AbsoluteUrl);
}
CheckingForiCloud = false;
});

创建UIDocument子类

public class MonkeyDocument : UIDocument
{
// the 'model', just a chunk of text in this case; must easily convert to NSData
NSString dataModel;
// model is wrapped in a nice .NET-friendly property
public string DocumentString 
{
get {
return dataModel.ToString ();
}
set {
dataModel = new NSString (value);
}
}
public MonkeyDocument (NSUrl url) : base (url)
{
DocumentString = "(default text)";
}
// contents supplied by iCloud to display, update local model and display (via notification)
public override bool LoadFromContents (NSObject contents, string typeName, out NSError outError)
{
outError = null;
Console.WriteLine ("LoadFromContents({0})", typeName);
if (contents != null)
dataModel = NSString.FromData ((NSData)contents, NSStringEncoding.UTF8);
// LoadFromContents called when an update occurs
NSNotificationCenter.DefaultCenter.PostNotificationName.("monkeyDocumentModified", this);
return true;
}
// return contents for iCloud to save (from the local model)
public override NSObject ContentsForType (string typeName, out NSError outError)
{
outError = null;
Console.WriteLine ("ContentsForType({0})", typeName);
Console.WriteLine ("DocumentText:{0}",dataModel);
NSData docData = dataModel.Encode (NSStringEncoding.UTF8);
return docData;
}
}

保存iCloud文档

var docsFolder = Path.Combine (iCloudUrl.Path, "Documents"); // NOTE: Documents 
folder is user-accessible in Settings
var docPath = Path.Combine (docsFolder, MonkeyDocFilename);
var ubiq = new NSUrl (docPath, false);
var monkeyDoc = new MonkeyDocument (ubiq);
monkeyDoc.Save (monkeyDoc.FileUrl, UIDocumentSaveOperation.ForCreating, saveSuccess => {
Console.WriteLine ("Save completion:" + saveSuccess);
if (saveSuccess) {
monkeyDoc.Open (openSuccess => {
Console.WriteLine ("Open completion:" + openSuccess);
if (openSuccess) {
Console.WriteLine ("new document for iCloud");
Console.WriteLine (" == " + monkeyDoc.DocumentString);
viewController.DisplayDocument (monkeyDoc);
} else {
Console.WriteLine ("couldn't open");
}
});
} else {
Console.WriteLine ("couldn't save");
}

有关iCloud的更多详细信息，请参阅此处