最新更新了APP之後,發現了一個問題,上傳附件的時候一直報錯 No such file or directory。 但是,文件的的確確就在Documents目錄下好好躺着。奇怪奇怪。
仔細對比之後,發現,生成附件的時候,絕對地址是:
/var/mobile/Containers/Data/Application/44C5E71D-B418-4FD3-A82A-45404C19465F/Documents/58961732/58961732_20141210003945072_Q2_1.jpg
其中Application後面有一串符號,表示當前是哪個APP。這個符號每次安裝都不一樣。
所以當我使用1.05版本,生成的附件,把地址放到數據庫中。下次使用1.06的版本,上傳附件,按照這個地址去找附件的時候,的確找不到了。
/var/mobile/Containers/Data/Application/74119C27-0ADF-4DB7-AE7D-705AB964B94C/Documents/58961732/58961732_20141210003945072_Q2_1.jpg
然後,無意中看到了這篇文章(第24), 裏面講到了擴展路徑。原來通過擴展路徑可以自由的切換絕對路徑和相對路徑。
NSString *Path = @"~/NSData.txt";
NSString *absolutePath = [Path stringByExpandingTildeInPath];
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);
運行結果:
2014-12-10 10:08:16.494 Flysurvey[2807:1377884] absolutePath:/var/mobile/Containers/Data/Application/B268916C-BDFF-4550-8A1D-1C88478921E4/NSData.txt
2014-12-10 10:08:16.498 Flysurvey[2807:1377884] Path:~/NSData.txt
另外,經過測試發現,stringByAbbreviatingWithTildeInPath這個方法,會根據當前的APP符號去縮短,所以,如果是上一版本的APP符號,是沒有辦法縮短的。
例如:
NSString *absolutePath = @"/var/mobile/Containers/Data/Application/AC672ACB-1BAB-4A6B-86DB-09E85FE3074F/NSData.txt";
NSString *path = [[absolutePath stringByAbbreviatingWithTildeInPath] copy];
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",path);
NSLog(@"hehe:%@ ",[path stringByExpandingTildeInPath] );
NSString *path2 = @"~/aa.txt";
NSLog(@"aa: %@", [path2 stringByExpandingTildeInPath]);
結果:
2014-12-10 10:20:15.637 Flysurvey[2886:1382167] absolutePath:/var/mobile/Containers/Data/Application/AC672ACB-1BAB-4A6B-86DB-09E85FE3074F/NSData.txt
2014-12-10 10:20:15.640 Flysurvey[2886:1382167] Path:/var/mobile/Containers/Data/Application/AC672ACB-1BAB-4A6B-86DB-09E85FE3074F/NSData.txt
2014-12-10 10:20:15.641 Flysurvey[2886:1382167] hehe:/var/mobile/Containers/Data/Application/AC672ACB-1BAB-4A6B-86DB-09E85FE3074F/NSData.txt
2014-12-10 10:20:15.641 Flysurvey[2886:1382167] aa: /var/mobile/Containers/Data/Application/D880650F-CF70-4990-AB05-86608CDECE93/aa.txt
可以看到,當前是D88開頭的,上一次AC6開頭的並沒有被轉換成功。依然是絕對路徑。
爲了兼容以前已經按照絕對路徑保存的情況,所以還要自己截取Documents後面的路徑,然後根據當前的APP,去轉換正確的絕對路徑。
於是,項目代碼作下修改:#import "Attachment.h"
#import "ZYFileUtil.h"
#import "ZYMyLog.h"
@implementation Attachment
@dynamic answer_index;
@dynamic answer_name;
@dynamic attachment_name;
@synthesize attachment_path = _attachment_path;
@dynamic attachment_type;
@dynamic project_id;
@dynamic upload_status;
@dynamic upload_time;
-(NSString *)attachment_path{
NSString *attachment_path_copy = [_attachment_path copy];
//2014-12-10 此版本(1.05.3)獲取路徑時,要處理以前絕對路徑的情況。同時要兼容以後版本相對路徑的情況。
if ([attachment_path_copy rangeOfString:@"~"].location == NSNotFound) {
//絕對路徑,去掉Documents前面的部分,增加當前的base路徑
NSInteger documentIndex = [attachment_path_copy rangeOfString:@"/Documents"].location;
NSMutableString *tempPath = [[attachment_path_copy substringFromIndex:documentIndex] mutableCopy];
[tempPath insertString:@"~" atIndex:0];
attachment_path_copy = [NSString stringWithFormat:@"%@",tempPath];
}
NSString *finalPath = [attachment_path_copy stringByExpandingTildeInPath];
[[ZYMyLog sharedMyLog] appendString:[NSString stringWithFormat:@"讀取數據庫附件地址爲: %@, 處理後的地址爲%@", _attachment_path, finalPath]];
return finalPath;
}
-(void)setAttachment_path:(NSString *)attachment_path{
//2014-12-10 此版本(1.05.3)之後,存進去的都是相對路徑
_attachment_path = [attachment_path stringByAbbreviatingWithTildeInPath];
[[ZYMyLog sharedMyLog] appendString:[NSString stringWithFormat:@"原附件地址爲:%@, 附件地址入庫內容爲: %@", attachment_path, _attachment_path]];
}