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NSFileManager在初始化文件的时候一不留神就进入陷进

今天调试一个程序,内容是在手机一个本地路径生成一个缓存文件,在生成本地路径的时候犯了一个错误,本着求原因的精神调试了2个小时,终于找到原因了

刚开始断点调试的时候,执行到第13行,这里死活不给写入数据,一直返回NO,看着我都蛋碎了,后来看到打印出来的路径在Library下,想着是不是这里不

允许用户在这里创建数据缓存,果然 把 2行 的 NSDocumentationDirectory 改成 NSDocumentDirectory,之后路径就变成了:

file:///var/mobile/Applications/79D7DD73-74C5-4ECE-BEF7-5988560A8AC2/Documents/436783070;之后这里的路径就可以写入数据了..

 

修改前:

 1 -(NSURL *)uniqueDocumentURL{ 2     NSArray *documentDictiories = [[NSFileManager defaultManager] URLsForDirectory:NSDocumentationDirectory inDomains:NSUserDomainMask];//注意这里的NSDocumentationDirectory 3     NSString * unique = [NSString stringWithFormat:@"%.0f",floor([NSDate timeIntervalSinceReferenceDate])]; 4     id URLObject = [documentDictiories firstObject] ; 5     return [URLObject URLByAppendingPathComponent:unique]; 6 } 7  8 -(NSURL *)imageURL{ 9     if (!_imageURL && self.image) {10         NSURL * url = [self uniqueDocumentURL];11         if (url) {12             NSData * imageData = http://www.mamicode.com/UIImageJPEGRepresentation(self.image, 1.0);13             if ([imageData writeToURL:url atomically:YES]) {//问题14                 _imageURL = url;15             }16         }17     }18     return _imageURL;19 }20 21 //控制台打印22 Printing description of url:23 file:///var/mobile/Applications/16614FF0-B641-4938-8BF8-91658759D4D8/Library/Documentation/436783128

 修改后:

 1 - (NSURL *)uniqueDocumentURL 2 { 3     NSArray *documentDirectories = [[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask]; 4     NSString *unique = [NSString stringWithFormat:@"%.0f", floor([NSDate timeIntervalSinceReferenceDate])]; 5     return [[documentDirectories firstObject] URLByAppendingPathComponent:unique]; 6 } 7  8 - (void)setImage:(UIImage *)image 9 {10     self.imageView.image = image;11 12     // when image is changed, we must delete files we‘ve created (if any)13     [[NSFileManager defaultManager] removeItemAtURL:_imageURL error:NULL];14     [[NSFileManager defaultManager] removeItemAtURL:_thumbnailURL error:NULL];15     self.imageURL = nil;16     self.thumbnailURL = nil;17 }18 19 20 Printing description of url:21 file:///var/mobile/Applications/79D7DD73-74C5-4ECE-BEF7-5988560A8AC2/Documents/436783070

 

NSFileManager在初始化文件的时候一不留神就进入陷进