Ios 无法在文件夹中写入nsdata

代码如下：

NSData * imageData = [NSData dataWithContentsOfURL:imageURL];                

 [imageData writeToFile:savedImagePath options:NSDataWritingAtomic error:&error];
                            if(error != nil)
 NSLog(@"write error %@", error);   

错误：

 write error Error Domain=NSCocoaErrorDomain Code=4 "The operation couldn’t be completed. (Cocoa error 4.)" UserInfo=0x8b7b850 {NSUnderlyingError=0x8b7d7c0 "The operation couldn’t be completed. No such file or directory", NSFilePath=/Users/alfa-1/Library/Application Support/iPhone Simulator/6.0/Applications/C24B228A-599E-4249-97A7-17775E8A546B/Library/Caches/ChannelListImages/http:/direct.domain.com/files/icons/1-all-cb.jpg, NSUserStringVariant=Folder}

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试试这个样品。它对我有用

在.h文件中声明-（NSString*）数据文件路径

-(NSString *) datafilepath{
NSArray *path=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documents=[path objectAtIndex:0];
return [documents stringByAppendingFormat:@"/sample.plist"];
}

任何你想执行写功能的地方

NSData * imageData = [NSData dataWithContentsOfURL:imageURL];                
[imageData writeToFile:[self datafilepath]atomically:YES];
 if(error != nil)
 NSLog(@"write error %@", error);   

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希望这有帮助

将数据写入文件之前。您需要创建文件夹。遵循以下步骤

#define APPLICATION_DATA_DIRECTORY @"Application Data"
+ (NSString *)cachesDirectoryPath
// Returns the path to the caches directory.  This is a class method because it's
// used by +applicationStartup.
{
    NSString *      result;
    NSArray *       paths;

    result = nil;
    paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
    if ( (paths != nil) && ([paths count] != 0) ) {
        assert([[paths objectAtIndex:0] isKindOfClass:[NSString class]]);
        result = [paths objectAtIndex:0];
    }
    result = [result stringByAppendingPathComponent:APPLICATION_DATA_DIRECTORY];
    if (![[NSFileManager defaultManager] fileExistsAtPath:result]) {
        [[NSFileManager defaultManager] createDirectoryAtPath:result withIntermediateDirectories:YES attributes:nil error:NULL];
    }

    return result;
}

在此之后：

#定义kPhotosDirectoryName@“应用程序文档”

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也许您必须创建中间文件夹…在NSLog中显示您的savedImagePath。路径可能无效中间文件夹是什么？如果路径是/folderA/folderB/folderC。folderA和folderB将是中间文件夹。如果要保存在folderC folderA中，则必须存在B和C才能在其中保存内容。@MohammedBrahim什么是savedImagePath？它应该是[documents stringByAppendingPathComponent:@“sample.plist”]；

    NSMutableString *savePath = [NSMutableString string];
    [savePath appendFormat:@"%@/%@",[YOURClass cachesDirectoryPath],kPhotosDirectoryName];

    [savePath appendFormat:@"/%@",YOUR_FILE_NAME];

    if (![[NSFileManager defaultManager] fileExistsAtPath:savePath]) {
        //write the data to file here
    }