我正在尝试对标准 Activity (打印、邮件、FaceBook 等)实现自定义 Activity ，但现在只需要标准打印(用于 AirPrint)和我自己通过直接方法进行的自定义打印。我显然遗漏了一些基本的东西，因为我的自定义类中的任何方法都没有被调用过。现在我只有一些 NSLog 语句来确定调用顺序，并使框架正常运行。

以下是我对自定义 Activity 类的测试代码:

//  PrintActivity.h

#import <UIKit/UIKit.h>

@interface PrintActivity : UIActivity

@end

还有.m

#import "PrintActivity.h"

@interface PrintActivity ()
@property (nonatomic, strong) UIWebView *dummyWebView;
@end

@implementation PrintActivity

- (NSString *)activityType {
    NSLog(@"activityType");
    return @"MetriScan Print";
}

- (NSString *)activityTitle {
    NSLog(@"activityTitle");
    return @"MetriScan\nPrint";
}

- (UIImage *)activityImage {
    NSLog(@"activityImage");
    UIImage *icon = [UIImage imageNamed:@"metriscan_57_c2a_3.png"];
    return icon;
}

- (BOOL)canPerformWithActivityItems:(NSArray *)activityItems {
    NSLog(@"canPerformWithActivityItems");
    return YES;
}

- (void)prepareWithActivityItems:(NSArray *)activityItems {
    NSLog(@"prepareWithActivityItems");
}

- (void)performActivity {
    NSLog(@"Do the actual printing here");
// My custom code here

}

这是主例程中的调用:

- (IBAction)printReport:(UIBarButtonItem *)sender {
    NSLog(@"Print Report");

    PrintActivity *metriscanPrint = [[PrintActivity alloc] init];

    UIViewPrintFormatter *printFormatter = [self.webView viewPrintFormatter];

    NSArray *activityItems = [NSArray arrayWithObjects:printFormatter, nil];
    NSArray *appActivities = [NSArray arrayWithObjects:metriscanPrint, nil];
    UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:appActivities];
    //activityController.excludedActivityTypes = [NSArray arrayWithObjects:UIActivityTypePostToFacebook, UIActivityTypePostToTwitter, UIActivityTypePostToWeibo, UIActivityTypeMail, UIActivityTypeMessage, nil];
    activityController.completionHandler = ^(NSString *activityType, BOOL completed) {
        sender.enabled = YES;
    };

    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        [self presentViewController:activityController animated:YES completion:nil];
    } else {
        sender.enabled = NO;
        self.printPop = [[UIPopoverController alloc] initWithContentViewController:activityController];
        [self.printPop presentPopoverFromBarButtonItem:sender permittedArrowDirections:UIPopoverArrowDirectionDown animated:YES];
    }

正如我所说，自定义类中的任何方法都没有被调用，但系统邮件、消息和复制图标显示在 Activity 表中，而不是打印图标。我只希望系统打印图标(和我自己的)。

如果我取消注释顶部的语句 block (并注释掉 NSArray *activityItems ..........)，系统邮件、消息、打印和复制图标。在这个实验中，我认为我通过创建自己的格式化程序来混合不同的方法，但这似乎是 WWDC 2012 上的建议？

如果我随后取消注释带有“excludeActivityTypes”的行，我只会得到系统打印图标。

我欢迎任何意见来帮助我解决这个问题。

如果有人知道任何示例代码来执行我想要的操作，那就太好了。

编辑:将代码更新为我的工作代码。

最佳答案

在过去的一周里，我也对 UIActivity 感到不安，Apple 确实需要更好地解释它并添加更多功能；试试这个:

打印 Activity .h

#import <UIKit/UIKit.h>
@interface PrintActivity : UIActivity
@end

打印 Activity .m

#import "PrintActivity.h"

@implementation PrintActivity

- (NSString *)activityType
{
   return @"MetriScan.Print";
}

- (NSString *)activityTitle
{
    return @"Print MtriScan";
}

- (UIImage *)activityImage
{   
    //***** Note: I recommend using two sizes, as the iPad's UIActivity image size differs from 
    //***** the iPhone's. Also, create @2x sizes for Retina compatible devices. So you will     
    //***** have a total of 4 images.
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
    return [UIImage imageNamed:@"test_72.png"];
}

    return [UIImage imageNamed:@"test_57.png"];
}

- (BOOL)canPerformWithActivityItems:(NSArray *)activityItems
{
    NSLog(@"%s", __FUNCTION__);
    return YES;
}

- (void)prepareWithActivityItems:(NSArray *)activityItems
{
    NSLog(@"%s",__FUNCTION__);
}

- (UIViewController *)activityViewController
{
    NSLog(@"%s",__FUNCTION__);
    return nil;
}

- (void)performActivity
{
    // This is where your custom print code should go

}

@end

别忘了制作这两个文件:

PrintProvider.h

#import <UIKit/UIKit.h>

@interface PrintProvider : UIActivityItemProvider <UIActivityItemSource>

@end

PrintProvider.m

#import "PrintProvider.h"

@implementation PrintProvider

#pragma mark - UIActivityItemSource

- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(NSString *)activityType
{
    NSLog(@"%s",__FUNCTION__);
    NSLog(@"%@", activityType);
    return [super activityViewController:activityViewController itemForActivityType:activityType];
}

@end  

现在我们终于可以调用它了:

- (IBAction)printReport:(UIBarButtonItem *)sender {


CustomProvider *customProvider =
                [[CustomProvider alloc]init];
                NSArray *items = [NSArray arrayWithObjects:customProvider,nil];

                CustomActivity *ca = [[CustomActivity alloc]init];

                UIActivityViewController *activityVC =
                [[UIActivityViewController alloc] initWithActivityItems:items
                                                  applicationActivities:[NSArray arrayWithObject:ca]];

                activityVC.excludedActivityTypes = @[UIActivityTypePostToWeibo,
                UIActivityTypeAssignToContact,UIActivityTypeCopyToPasteboard,
                UIActivityTypeSaveToCameraRoll,UIActivityTypeMail,UIActivityTypePostToTwitter,
                UIActivityTypePostToFacebook,UIActivityTypeMessage];

                activityVC.completionHandler = ^(NSString *activityType, BOOL completed)
                {
                    NSLog(@" activityType: %@", activityType);
                    NSLog(@" completed: %i", completed);
                };

                    self.popoverController = [[UIPopoverController alloc] initWithContentViewController:activityVC];

                    CGRect rect = [[UIScreen mainScreen] bounds];

                    [self.popoverController
                     presentPopoverFromRect:rect inView:self.view
                     permittedArrowDirections:0
                     animated:YES];
}

关于ios - 将自定义 Activity 添加到 UIActivityController 时出现问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12751891/