UIActivityViewController Gmail分享主题和正文是否空白？

Question

我使用UIActivityViewController来显示共享。在我选择邮件应用程序的列表中，主题和正文设置正确，Gmail应用程序中的位置为空。

- (void)shareAVideoWithSubject:(NSString*)subject Link:(NSString *)string onViewController:(UIViewController *)viewController fromView:(UIView *)view {

    _activityViewController =
    [[UIActivityViewController alloc] initWithActivityItems:@[string]
                                      applicationActivities:nil];
    _activityViewController.excludedActivityTypes = @[UIActivityTypePrint, UIActivityTypeAssignToContact, UIActivityTypeSaveToCameraRoll, UIActivityTypeAddToReadingList, UIActivityTypeAirDrop];
    [_activityViewController setValue:subject forKey:@"subject"];


    UIWindow *window = [[[UIApplication sharedApplication] delegate]window];

    //if iPhone
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {
        if(!viewController){
            viewController = ((SWRevealViewController*)window.rootViewController).presentedViewController;
        }
        [viewController presentViewController:_activityViewController
                                     animated:YES
                                   completion:nil];

    }   
    //if iPad
    else
    {
        // Change Rect to position Popover
        popup = [[UIPopoverController alloc] initWithContentViewController:_activityViewController];
        UIBarButtonItem *barButton = [[UIBarButtonItem alloc] initWithCustomView:view];
        [popup presentPopoverFromBarButtonItem:barButton permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }
}

我在StackOverFlow上检查了以下两个问题。

1. UIActivityViewController not showing body text in gmail

2. UIActivityViewController not showing body text in gmail

这些不是我的问题的答案，因为他们在列表中添加新活动，而我希望iOS显示所有可共享的应用程序。在这种情况下，Gmail共享正在变空。

提前致谢。 添加截图，

Answer 1

[_activityViewController setValue:subject forKey:@"subject"];没有记录设置电子邮件主题的方式。
设置正文和主题的正确方法（iOS 7.0及更高版本） - 在要共享的项目上实施UIActivityItemSource协议。

//  EmailItemProvider.h
@interface EmailItemProvider : NSObject <UIActivityItemSource>
@property (nonatomic, strong) NSString *subject;
@property (nonatomic, strong) NSString *body;
@end

//  EmailItemProvider.m
#import "EmailItemProvider.h"

@implementation EmailItemProvider

- (id)activityViewControllerPlaceholderItem:(UIActivityViewController *)activityViewController {
    return _body;
}

- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(NSString *)activityType {
    return _body;
}

- (NSString *)activityViewController:(UIActivityViewController *)activityViewController subjectForActivityType:(NSString *)activityType {
    return _subject;
}
@end

而不是呈现它：

EmailItemProvider *emailItem = [EmailItemProvider new];
emailItem.subject = @"Subject";
emailItem.body = @"Body";

UIActivityViewController *activityViewController =
[[UIActivityViewController alloc] initWithActivityItems:@[emailItem]
                                  applicationActivities:nil];
[self presentViewController:activityViewController animated:YES completion:nil];

这将在邮件应用上设置正文和主题，但似乎Gmail应用忽略主题并将其设置为正文。

重要：好像Gmail应用中存在错误。传递&个字符会使邮件主题和正文变为空。请改用&。其他特殊字符未经过测试。

Answer 2

对于Swift（4）恋人：

activityViewController(_:subjectForActivityType:)允许我们将主题设为共享方法。

struck stackelementS {
       void* contents;
       struct stackelementS* next;
}

typedef struct stackelementS stackelement;

struct stackS {
       stackelement* top; 

}

typedef struct stackS* stack;

Answer 3

UIActivityViewController * activityViewController = [[UIActivityViewController alloc] initWithActivityItems：@ [@＆＃34;你的身体字符串要分享＆＃34;]                                   applicationActivities：无];

[activityViewController setValue：@＆＃34;您的电子邮件主题＆＃34; forKey：@＆＃34受试者＃34;];

activityViewController.completionHandler = ^（NSString * activityType，BOOL completed）{     // ... };