ios - NSData datawithcontentsofffile 返回 null

Question

我有以下代码用于从 iphone 的文档目录中获取文件:

NSString *docsDir;
NSString *realpath;
NSArray *dirPaths;
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];

realpath=[[NSString alloc] initWithString:
          [docsDir stringByAppendingPathComponent: @"2_program.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: realpath ] == YES)
{
    NSLog(@"find file");
    NSData *uploadedData=[NSData dataWithContentsOfFile:realpath];
    NSString * uploadedDataBase64= [NSString base64forData:uploadedData];
    NSLog(@"base64: %@",uploadedDataBase64);
}
else
{
    NSLog(@"not found");
}

filemanager 找到文件但 nsdata 返回 null 但是它们都得到了相同的路径

我的文件大小约为 60kb

任何想法为什么会发生？我错过了什么吗？

Answer 1

尝试 this Matt Gallagher 的 NSData+Base64 类别以及下面的代码

    NSString *realpath=[[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject] stringByAppendingPathComponent: @"2_program.db"];
if ([[NSFileManager defaultManager] fileExistsAtPath:realpath]){
    NSLog(@"find file");
    NSData *uploadedData=[NSData dataWithContentsOfFile:realpath];
    NSString *uploadedDataBase64=[[[NSString alloc]initWithData:uploadedData encoding:NSUTF8StringEncoding] base64EncodedString];
    NSLog(@"base64: %@",uploadedDataBase64);
}
else{
    NSLog(@"not found");
}