将数据保存到缓存目录（iPhone）时出错 [英] Error saving data to cache directory (iPhone)

问题描述

我尝试使用以下代码保存图片：

   - （void）writeData {
 
 if（cacheFileName == nil）
 return; 
 if（cacheDirectoryPath == nil）
 return; 
 
 
 if（！[[NSFileManager defaultManager] fileExistsAtPath：[self filePath]]）{
 
 NSData * imageData = UIImageJPEGRepresentation（self.image，0.9）; 
 
 NSError * writeError = nil; 
 
 BOOL didWrite = [imageData writeToFile：[self filePath] options：NSAtomicWrite error：& writeError]; 
 
 if（writeError）
 NSLog（[writeError localizedDescription]）; 
 
 if（didWrite）
 NSLog（@image saved）; 
 else 
 NSLog（@image not saved）; 
 
 
} 
} 
 
 
 
 
 
  - （NSString *）filePath {
 
 NSArray * paths = NSSearchPathForDirectoriesInDomains（NSCachesDirectory，NSUserDomainMask，YES）; 
 NSString * cacheDirectory = [paths objectAtIndex：0]; 
 NSString * filename = [cacheDirectory stringByAppendingPathComponent：cacheDirectoryPath]; 
 filename = [filename stringByAppendingPathComponent：cacheFileName]; 
 NSLog（filename）; 
 
 return filename; 
 
} 
  

我收到错误：

  2009-06-23 16：39：19.740 XXX [33454：20b]操作无法完成。 （可能错误4.）
  

我看了看这个错误有以下含义： p>

  NSFileNoSuchFileError = 4，//尝试对不存在的文件执行文件系统操作
  
 
 
 
这不合理，因为文件不应该存在。
 
 
 
已尝试编写png表示并使用方便方法：
   - （BOOL）writeToFile：（NSString *）path atomically :( BOOL）flag 
  
 
 
我使用类似的代码保存plist，他们工作正常。我不知道什么问题是。任何想法？
解决方案
我看到你在缓存目录中使用一些中间目录，是/他们创建？如果不尝试删除它们或使用
   -  [NSFileManager createDirectoryAtPath：withIntermediateDirectories：attributes：error：] 
  
以在
之前创建 
I am trying to save images using the following code:
- (void)writeData{

    if(cacheFileName==nil)
        return;
    if(cacheDirectoryPath==nil)
        return;


    if (![[NSFileManager defaultManager] fileExistsAtPath:[self filePath]]) {        

        NSData *imageData = UIImageJPEGRepresentation(self.image, 0.9);

        NSError *writeError= nil;

        BOOL didWrite =  [imageData writeToFile:[self filePath] options:NSAtomicWrite error:&writeError];

        if(writeError)
            NSLog([writeError localizedDescription]);

        if(didWrite)
            NSLog(@"image saved");
        else
            NSLog(@"image not saved");


    }
}





 - (NSString *)filePath{

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); 
    NSString *cacheDirectory = [paths objectAtIndex:0]; 
    NSString *filename = [cacheDirectory stringByAppendingPathComponent:cacheDirectoryPath]; 
    filename = [filename stringByAppendingPathComponent:cacheFileName]; 
    NSLog(filename);

    return filename;

}
I get an error:
2009-06-23 16:39:19.740 XXX[33454:20b] Operation could not be completed. (Cocoa error 4.)
I looked this up and see the error has the following meaning:
 NSFileNoSuchFileError = 4,                 // Attempt to do a file system operation on a non-existent file
Which doesn't make sense since the file shouldn't exist.

I have tried writing the png representation and using the convenience method:
- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)flag
I am using similar code to save plists, and they work fine. I am not sure what the problem is. Any ideas?
解决方案
I see that you use some intermediate directory within the Cache Directory, are it/they created? If not try removing them or use 
-[NSFileManager createDirectoryAtPath:withIntermediateDirectories:attributes:error:]
to create them before

                        
这篇关于将数据保存到缓存目录（iPhone）时出错的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！