首先第一步开启iCloud服务：

image.png

然后就是看代码了。

先定义一个继承UIDocument的，

它用来存储文件的Data.其内部响应外部调用。先看UIDocument的接口，

#pragma mark *** Simple Reading and Writing ***

// These methods will be all most apps need to access files. Applications with complex reading and writing needs should see the Advanced Reading and Writing section below.

// Typical subclasses will implement this method to do reading. UIKit will pass NSData typed contents for flat files and NSFileWrapper typed contents for file packages.
// typeName is the UTI of the loaded file.
- (BOOL)loadFromContents:(id)contents ofType:(nullable NSString *)typeName error:(NSError **)outError API_UNAVAILABLE(tvos);

// Typical subclasses will implement this method and return an NSFileWrapper or NSData encapsulating a snapshot of their data to be written to disk during saving.
// Subclasses that return something other than a valid NSFileWrapper or NSData instance, or don't override this method must override one of the writing methods in the Advanced Saving section to write data to disk.
- (nullable id)contentsForType:(NSString *)typeName error:(NSError **)outError API_UNAVAILABLE(tvos);

再看看MyDocument的代码。

#import <UIKit/UIKit.h>

@interface MyDocument : UIDocument
@property(strong,nonatomic)NSData * myData;
@end

@implementation MyDocument

//读取icloud数据调用，响应openWithCompletionHandler
- (BOOL)loadFromContents:(id)contents ofType:(nullable NSString *)typeName error:(NSError **)outError __TVOS_PROHIBITED
{
    self.myData = [contents copy];
    return true;
}

//保存数据、修改数据到icloud，响应save
- (nullable id)contentsForType:(NSString *)typeName error:(NSError **)outError __TVOS_PROHIBITED
{
    if (!self.myData) {
        self.myData = [[NSData alloc] init];
    }
    return self.myData;
}
@end

怎么使用，

#import "MyDocument.h" 


#define UbiquityContainerIdentifier @"iCloud.com.qzzn.damon.iosIcloudDemoa"
@interface ViewController ()<UIDocumentPickerDelegate>
@property(strong,nonatomic) NSUbiquitousKeyValueStore  *myKeyValue; //字符串使用
@property(strong,nonatomic) MyDocument  *myDocument;   //icloud数据处理
@property(strong,nonatomic) NSMetadataQuery *myMetadataQuery;//icloud查询需要用这个类
@property(strong,nonatomic) NSURL *myUrl;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(10, 100, 100, 30)];
    [button setTitle:@"保存字符串" forState:UIControlStateNormal];
    [button setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [button addTarget:self action:@selector(saveString) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];
    
    UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(10, 200, 100, 30)];
    [button2 setTitle:@"读取字符串" forState:UIControlStateNormal];
    [button2 setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [button2 addTarget:self action:@selector(loadString) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button2];
    
    UIButton *button3 = [[UIButton alloc] initWithFrame:CGRectMake(10, 300, 100, 30)];
    [button3 setTitle:@"上传资料" forState:UIControlStateNormal];
    [button3 setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [button3 addTarget:self action:@selector(uploadDoc) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button3];
    
    UIButton *button5 = [[UIButton alloc] initWithFrame:CGRectMake(10, 400, 100, 30)];
    [button5 setTitle:@"修改资料" forState:UIControlStateNormal];
    [button5 setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [button5 addTarget:self action:@selector(editDoc) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button5];
    
    UIButton *button4 = [[UIButton alloc] initWithFrame:CGRectMake(10, 500, 200, 30)];
    [button4 setTitle:@"获取最新数据" forState:UIControlStateNormal];
    [button4 setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [button4 addTarget:self action:@selector(downloadDoc) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button4];
    
    UIButton *button6 = [[UIButton alloc] initWithFrame:CGRectMake(10, 600, 100, 30)];
    [button6 setTitle:@"删除资料" forState:UIControlStateNormal];
    [button6 setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [button6 addTarget:self action:@selector(removeDoc) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button6];
    
    self.myKeyValue = [NSUbiquitousKeyValueStore defaultStore];
    //字符串
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(StringChange:) name:NSUbiquitousKeyValueStoreDidChangeExternallyNotification object:self.myKeyValue];
    //文档
    //数据获取完成
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(MetadataQueryDidFinishGathering:) name:NSMetadataQueryDidFinishGatheringNotification object:self.myMetadataQuery];
    //数据更新通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(MetadataQueryDidUpdate:) name:NSMetadataQueryDidUpdateNotification object:self.myMetadataQuery];
    
    //文档
    self.myMetadataQuery = [[NSMetadataQuery alloc] init];
}

-(void)StringChange:(NSNotification*)noti
{
    NSLog(@"%@",noti.object);
}

-(void)saveString{
    NSLog(@"savestring");
    static int i = 0;
    i++;
    if (i==1) {
        [self.myKeyValue setObject:@"damon" forKey:@"name"];
    }
    else if (i==2){
        [self.myKeyValue setObject:@"dong" forKey:@"name"];
        i=0;
    }
    [self.myKeyValue synchronize];
}

-(void)loadString{
    NSLog(@"loadstring");
    NSLog(@"name:%@",[self.myKeyValue objectForKey:@"name"]);
}

//创建文档并上传
-(void)uploadDoc{
    NSLog(@"uploadDoc");
    //文档名字
    NSString *fileName =@"atest.txt";
    
    fileName = @"OpenGL ES 2.0 编程指南 中文版@www.java1234.com.pdf";
    
    NSURL *url = [self getUbiquityContainerUrl:fileName];
    if (!url) {
        return;
    }
    NSLog(@"%@",url);
    
  NSURL *  oldurl = [NSURL fileURLWithPath:[[NSBundle mainBundle]pathForResource:@"OpenGL ES 2.0 编程指南 中文版@www.java1234.com" ofType:@"pdf"]];
    MyDocument *doc = [[MyDocument alloc] initWithFileURL:oldurl];
    //文档内容
//    NSString*str = @"测试文本数据";
//    doc.myData = [str dataUsingEncoding:NSUTF8StringEncoding];
    [doc saveToURL:url forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL success) {
        if (success) {
            NSLog(@"创建成功");
        }
        else{
            NSLog(@"创建失败");
        }
    }];
}

//保存文档，只是save参数不一样用UIDocumentSaveForOverwriting
-(void)editDoc{
    NSLog(@"editDoc");
    //文档名字
    NSString *fileName =@"test.txt";
    NSURL *url = [self getUbiquityContainerUrl:fileName];
    MyDocument *doc = [[MyDocument alloc] initWithFileURL:url];
    //文档内容
    NSString*str = @"修改了数据";
    doc.myData = [str dataUsingEncoding:NSUTF8StringEncoding];
    [doc saveToURL:url forSaveOperation:UIDocumentSaveForOverwriting completionHandler:^(BOOL success) {
        if (success) {
            NSLog(@"修改成功");
        }
        else{
            NSLog(@"修改失败");
        }
    }];
}

//移除文档
-(void)removeDoc{
    NSLog(@"removeDoc");
    NSString *fileName =@"test.txt";
    NSURL *url = [self getUbiquityContainerUrl:fileName];
    NSError* error;
    [[NSFileManager defaultManager] removeItemAtURL:url error:&error];
    if (error) {
        NSLog(@"%@",error.localizedDescription);
    }else{
        NSLog(@"remove success");
    }
}

//获取最新数据
-(void)downloadDoc{
    NSLog(@"downloaddoc");
    //设置搜索文档
    [self.myMetadataQuery setSearchScopes:@[NSMetadataQueryUbiquitousDocumentsScope]];
    [self.myMetadataQuery startQuery];
    
    
    [self importDocumentFromiCloud];
}

//获取成功
-(void)MetadataQueryDidFinishGathering:(NSNotification*)noti{
    NSLog(@"MetadataQueryDidFinishGathering");
    NSArray *items = self.myMetadataQuery.results;//查询结果集
    //便利结果
    [items enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        NSMetadataItem*item =obj;
        //获取文件名
        NSString *fileName = [item valueForAttribute:NSMetadataItemFSNameKey];
        //获取文件创建日期
        NSDate *date = [item valueForAttribute:NSMetadataItemFSContentChangeDateKey];
        NSLog(@"%@,%@",fileName,date);
        
        //file:///private/var/mobile/Containers/Shared/AppGroup/AA2BACA6-84BC-4918-8499-AD6BD445EDF6/File%20Provider%20Storage/%E7%83%AD%E8%85%BE%E8%85%BE.pdf
        //读取文件内容
        MyDocument *doc =[[MyDocument alloc] initWithFileURL:[self getUbiquityContainerUrl:fileName]];
        [doc openWithCompletionHandler:^(BOOL success) {
            if (success) {
                NSLog(@"读取数据成功.");
                NSString *dataText = [[NSString alloc] initWithData:doc.myData encoding:NSUTF8StringEncoding];
                NSLog(@"数据:%@",dataText);
            }else{
                
            }
        }];
    }];
}

//数据有更新
-(void)MetadataQueryDidUpdate:(NSNotification*)noti{
    NSLog(@"icloud数据有更新");
}

//获取url
-(NSURL*)getUbiquityContainerUrl:(NSString*)fileName{
    if (!self.myUrl) {
        self.myUrl = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:UbiquityContainerIdentifier];//URLForUbiquityContainerIdentifier
        if (!self.myUrl) {
            NSLog(@"未开启iCloud功能");
            return nil;
        }

    }
    NSLog(@"myUrl:%@",self.myUrl);
    NSURL *url = [self.myUrl URLByAppendingPathComponent:@"Documents"];
    url = [url URLByAppendingPathComponent:fileName];
    
    NSLog(@"url= %@",url);
    return url;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(void)importDocumentFromiCloud{
    
//    - (void)presentDocumentPicker {
        NSArray *documentTypes = @[@"public.content", @"public.text", @"public.source-code ", @"public.image", @"public.audiovisual-content", @"com.adobe.pdf", @"com.apple.keynote.key", @"com.microsoft.word.doc", @"com.microsoft.excel.xls", @"com.microsoft.powerpoint.ppt"];
        
        UIDocumentPickerViewController *documentPickerViewController = [[UIDocumentPickerViewController alloc] initWithDocumentTypes:documentTypes inMode:UIDocumentPickerModeOpen];
        documentPickerViewController.delegate = self;
        [self presentViewController:documentPickerViewController animated:YES completion:nil];
//    }
    
}
#pragma mark - UIDocumentPickerDelegate

- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentAtURL:(NSURL *)url {
    
    
    NSArray *array = [[url absoluteString] componentsSeparatedByString:@"/"];
    NSString *fileName = [array lastObject];
    fileName = [fileName stringByRemovingPercentEncoding];
    NSLog(@"url,fileName:::%@/%@",url,fileName);
    
    MyDocument *iCloudDoc = [[MyDocument alloc]initWithFileURL:url];
       
       [iCloudDoc openWithCompletionHandler:^(BOOL success) {
           if (success) {
               
               [iCloudDoc closeWithCompletionHandler:^(BOOL success) {
                   NSLog(@"关闭成功");
               }];
               
               NSString *content = [[NSString alloc]initWithData:iCloudDoc.myData encoding:NSUTF8StringEncoding];// iCloudDoc.myData
              
               NSLog(@"%@",content);
               
           }
       }];
    
}

@end