AFN上传图片文件 遇到 NSURL中fileURLWithPath和URLWithString 的区别的问题

用AFN上传本地文件的时候遇到的本地文件路径的问题

//MARK:2.66 H5图片上传接口- (void)uploadImageWithImageFile:(UIImage *)imageFile imageName:(NSString *)imageName complete:(void(^)(id model))completeBlock failure:(void(^)())failureBlock {    NSString *url = SERVER_INTERFACE_HTML_UPLOADIMAGE;    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];    NSMutableDictionary *parameters = [NSMutableDictionary dictionaryWithCapacity:0];//    [parameters setValue:imageFile forKey:@"imagefile"];    [parameters setValue:imageName forKey:@"imagename"];    manager.responseSerializer = [AFJSONResponseSerializer serializer];    WEAKSELF    [manager POST:url parameters:parameters constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {        //        NSURL *fileUrl = [NSURL URLWithString:@"/Users/liliansi/Desktop/testshot.png"];//        [formData appendPartWithFileURL:[NSURL URLWithString:fileUrl] name:@"imagefile" fileName:imageName mimeType:@"image/jpg" error:NULL];//        [formData appendPartWithFileData:[NSData dataWithContentsOfFile:fileUrl] name:@"imagefile" fileName:imageName mimeType:@"image/jpg"];        VcUser *user = [[VcUserManager sharedInstance] currentUser];        NSString *path = [[[[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"users"] stringByAppendingPathComponent:user.userID.stringValue] stringByAppendingPathComponent:self.productid.stringValue];        BOOL bo = [[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];        NSAssert(bo,@"创建目录失败");        NSString *filePath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%@",imageName]];        NSURL *fileURL = [NSURL fileURLWithPath:filePath];//        NSString *path1 = [path stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];//        NSBundle *bundle = [NSBundle bundleWithPath:path];//        NSURL *fileURL = [bundle URLForResource:imageName withExtension:nil];//        NSString *filePath = [[[NSBundle mainBundle]resourcePath]stringByAppendingPathComponent:imageName];//        NSURL *fileURL = [NSURL URLWithString:filePath];        NSLog(@"\npath: %@\nimageName: %@",path,imageName);        NSLog(@"\nfileURL: %@",fileURL);        [formData appendPartWithFileURL:fileURL name:@"imagefile" error:NULL];    } success:^(AFHTTPRequestOperation *operation, id responseObject) {        NSLog(@"%@", [operation responseString]);        NSDictionary *dict = (NSDictionary *)responseObject;        NSString* code = [dict objectForKey:@"code"];        if (code == nil || ![code isEqualToString:SERVER_RESPONSE_CODE_SUCCESS]) {            NSString* errDesc = [dict objectForKey:@"desc"];            [weakSelf.view makeToast:errDesc duration:2.0 position:@"bottom"];            if (failureBlock) {                failureBlock();            }            return;        }        NSDictionary *imageinfo = [dict objectForKey:@"imageinfo"];        if (imageinfo && ![imageinfo isKindOfClass:[NSNull class]]) {            VcImageModel *pictureModel = [[VcImageModel alloc]initWithAttributesDictionary:imageinfo];            if (completeBlock) {                completeBlock(pictureModel);            }        }        NSLog(@"上传完成");    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {        NSLog(@"上传失败->%@", error);        NSLog(@"错误 %@", error.localizedDescription);        if (failureBlock) {            failureBlock();        }    }];}

问题以及总结：
初始化URL，其中 filePath 是一个本地的文件路径。
NSURL *appURL = [NSURL URLWithString:filePath];

在真机上可以初始化appURL，但模拟器上appURL为nil；

正确初始化一个本地文件的URL，应使用下边的方法，真机和模拟器都没问题

NSURL *appURL = [NSURL fileURLWithPath:url];

做实验：
NSString *str=@”http://www.9yunping.com/index“;
NSURL *url1=[NSURL fileURLWithPath:str];
NSURL *url2=[NSURL URLWithString:str];
NSLog(@”url1=%@”,url1);
NSLog(@”url2=%@”,url2);
输出结果为：
url1=http:/www.9yunping.com/index – file:///
url2=http://www.9yunping.com/index
通过上面的输出结果可知：
fileURLWithPath是将str转化为文件路径，可以自动的去掉“/”。而URLWithString紧紧是将url2转化成NSURL类型，对于它的内容没有任何的改变。