iOS 将相册中的图片上传至服务器

在使用app时，从相册中选取图片作为头像是很常用的操作，首先打开相册选择图片，然后将图片保存至本应用的document，最后将document中图片的路径保存至NSUserDefaults和服务器。

//从相册中选取图片或拍照
- (void)btnActionForEditPortrait:(id) sender {
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    picker.allowsEditing = YES;
    [self presentViewController:picker animated:YES completion:NULL];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    
    _avatar = info[UIImagePickerControllerOriginalImage];

    [self saveImage:_avatar WithName:@"userAvatar"];

    //处理完毕，回到个人信息页面
    [picker dismissViewControllerAnimated:YES completion:NULL];
    [_tableView reloadData];
}

//保存图片
- (void)saveImage:(UIImage *)tempImage WithName:(NSString *)imageName
{
    NSData* imageData = UIImagePNGRepresentation(tempImage);
    NSString* documentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString* totalPath = [documentPath stringByAppendingPathComponent:imageName];
    
    //保存到 document
    [imageData writeToFile:totalPath atomically:NO];
    
    //保存到 NSUserDefaults
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    [userDefaults setObject:totalPath forKey:@"avatar"];
    
    //上传服务器
    [[HSLoginClass new] uploadAvatar:totalPath];
}

//从document取得图片
- (UIImage *)getImage:(NSString *)urlStr
{
    return [UIImage imageWithContentsOfFile:urlStr];
}