ios NSData writeToFile 不起作用
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NSData writeToFile not working
提问by user346443
I cant seem to get nsdata to write to a file. Any ideas what i may be doing wrong. Thanks in advance.
我似乎无法让 nsdata 写入文件。任何想法我可能做错了什么。提前致谢。
NSString* filename = @"myfile.txt";
NSString *applicationDocumentsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *storePath = [applicationDocumentsDir stringByAppendingPathComponent:filename];
if ([fileManager fileExistsAtPath:applicationDocumentsDir])
NSLog(@"applicationDocumentsDir exists"); // verifies directory exist
NSData *data = [NSData dataWithContentsOfURL:URL];
if (data) {
NSString *content = [[NSString alloc] initWithBytes:[data bytes]
length:[data length] encoding: NSUTF8StringEncoding];
NSLog(@"%@", content); // verifies data was downloaded correctly
NSError* error;
[data writeToFile:storePath options:NSDataWritingAtomic error:&error];
if(error != nil)
NSLog(@"write error %@", error);
}
I keep getting the error
我不断收到错误
"The operation couldn't be completed. No such file or directory"
回答by user346443
Try
尝试
NSString *storePath = [applicationDocumentsDir stringByAppendingPathComponent:@"myfile.txt"];
And
和
if ([[NSFileManager defaultManager] fileExistsAtPath:storePath])
NSLog(@"applicationDocumentsDir exists");
回答by Jeff
To get more information, you can use
要获取更多信息，您可以使用
writeToFile:options:error:
writeToFile:options:error:
instead of
代替
writeToFile:atomically:
writeToFile：以原子方式：
but you need to create all the subdirectories in the path prior to doing the write. Like this:
但是您需要在写入之前创建路径中的所有子目录。像这样：
// if the directory does not exist, create it...
if ( [fileManager fileExistsAtPath:dir_path] == NO ) {
if ( [fileManager createDirectoryAtPath:dir_path withIntermediateDirectories:NO attributes:NULL error:&error] == NO ) {
NSLog(@"createDirectoryAtPath failed %@", error);
}
}
