ios - 如何使用 UIActivityItemProvider 通过 UIActivityViewController 发送带有附件的电子邮件？

Question

我正在尝试使用 UIActivityItemProvider 通过电子邮件附件从我的应用程序中共享文件。我还需要填充电子邮件的主题行，并将附件名称指定为与设备上存储的文件名称不同的名称。

这是我正在使用的代码。问题是电子邮件中缺少附件。

@interface ItemProvider:UIActivityItemProvider
@property (nonatomic, strong) NSURL *filepath;
@property (nonatomic, strong) NSString *emailBody;
@property (nonatomic, strong) NSString *emailSubject;
@end

@implementation ItemProvider

- (id)initWithPlaceholderItem:(id)placeholderItem
{
    //Initializes and returns a provider object with the specified placeholder data
    return [super initWithPlaceholderItem:placeholderItem];
}

- (id)item
{
    //Generates and returns the actual data object
    return [NSDictionary dictionary];
}

// The following are two methods in the UIActivityItemSource Protocol
// (UIActivityItemProvider conforms to this protocol) - both methods required
#pragma mark UIActivityItemSource

//- Returns the data object to be acted upon. (required)
- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(NSString *)activityType
{


    if ([activityType isEqualToString:UIActivityTypeMail]) {
        return @{@"body":self.emailBody, @"url":self.filepath};
    }


    return @{@"body":self.emailBody, @"url":self.filepath};
}

//- Returns the placeholder object for the data. (required)
//- The class of this object must match the class of the object you return from the above method
- (id)activityViewControllerPlaceholderItem:(UIActivityViewController *)activityViewController
{
    return @{@"body":self.emailBody, @"url":self.filepath};
}

-(NSString *) activityViewController:(UIActivityViewController *)activityViewController subjectForActivityType:(NSString *)activityType {
    return self.emailSubject;
}

@end

然后在我的 viewController 中我这样做:

      ItemProvider *provider = [[ItemProvider alloc] initWithPlaceholderItem:@{@"body":emailBody, @"url":filePath}];
    provider.emailBody = emailBody;
    provider.emailSubject = info.title;
    provider.filepath = filePath;
    NSArray *activityItems = @[provider];

    // Build a collection of custom activities (if you have any)
//    NSMutableArray *customActivities = [[NSMutableArray alloc] init];


    UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];

    [self presentViewController:activityController animated:YES completion:nil];

Answer 1

对于那些仍在寻找解决方案的人来说，有一个更优雅的自定义 UIActivityViewController 解决方案。要解决原始问题，附件未显示的原因是因为它应该是一个单独的 UIActivityItemProvider 对象。

因此解决方案是创建两个 UIActivityItemProvider 子类，一个用于包装“emailBody”和“emailSubject”，另一个用于包装附件。为附件使用 UIActivityItemProvider 的好处是您有机会延迟处理附件直到需要它，而不是在呈现 UIActivityViewController 之前这样做。

实现 AttachmentProvider 类来提供附件，如下所示:

@implementation AttachmentProvider : UIActivityItemProvider

- (id)item {
    if ([self.activityType isEqualToString:UIActivityTypeMail]) {

        /* Replace with actual URL to a file. Alternatively
         * you can also return a UIImage.
         */

        return [NSData dataWithContentsOfURL:dataURL];
    }
    return nil;
}

@end

实现 EmailInfoProvider 类来提供电子邮件正文和主题类，如下所示:

@implementation EmailInfoProvider : UIActivityItemProvider

- (id)item {
    return @"Your email body goes here";
}

- (NSString *)activityViewController:(UIActivityViewController *)activityViewController subjectForActivityType:(NSString *)activityType {
    if ([activityType isEqualToString:UIActivityTypeMail]) {
        return @"Your subject goes here";
    }
    return nil;
}

@end

然后您可以在您的 viewController 中使用这两个项目创建一个 UIActivityViewController，如下所示:

- (void)shareAction {

    AttachmentProvider *attachment  = [[AttachmentProvider alloc] init];
    EmailInfoProvider *emailContent = [[EmailInfoProvider alloc] init];

    // You can provider custom -(id)init methods to populate EmailInfoProvider

    UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:@[attachment, emailContent] applicationActivities:nil];
    [self presentViewController:activityController animated:YES completion:nil];
}