ios7 uiactivityviewcontroller

@interface  () <UIAlertViewDelegate>

@property (nonatomic, strong) NSArray *activityItems;
@end

@implementation 

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex{
    //点击button事件后调用
    [self activityDidFinish:YES];
}

- (NSString *) activityType{
//    NSLog(@"csj %@",[[NSBundle mainBundle].bundleIdentifier stringByAppendingFormat:@".%@", NSStringFromClass([self class])]);
    //com.pixolity.ios.cookbook.Presenting-Custom-Sharing-Options-with-UIActivityViewController.StringReverserActivity
    return [[NSBundle mainBundle].bundleIdentifier stringByAppendingFormat:@".%@", NSStringFromClass([self class])];
}

//反响字符串
- (NSString *) activityTitle{
    return @"Reverse String";
}

//设置按钮图标
- (UIImage *) activityImage{
    return [UIImage imageNamed:@"Reverse"];
}

//重写返回，默认不返回
- (BOOL)canPerformWithActivityItems:(NSArray *)activityItems{
    /**
     *  (
     Item 1,
     Item 2,
     Item 3
     )

     */
    for (id object in activityItems){
        if ([object isKindOfClass:[NSString class]]){
            return YES;
        }
    }
    
    return NO;
    
}

//点击按钮
- (void) prepareWithActivityItems:(NSArray *)activityItems{
    //创建可变数组
    NSMutableArray *stringObjects = [[NSMutableArray alloc] init];
    //快速枚举 item
    for (id object in activityItems){
        if ([object isKindOfClass:[NSString class]]){
            [stringObjects addObject:object];
        }
    }
    
    //copy给items
    self.activityItems = [stringObjects copy];
}

//倒转 string
- (NSString *)reverseOfString:(NSString *)paramString{
    
    NSMutableString *reversed = [[NSMutableString alloc]
                                 initWithCapacity:paramString.length];
    
    for (NSInteger counter = paramString.length - 1;//6-1 = 5(counter)
         counter >= 0;
         counter--){
        [reversed appendFormat:@"%c", [paramString characterAtIndex:counter]];
    }
    
    return [reversed copy];
    
}


- (void)performActivity{
    NSMutableString *reversedStrings = [[NSMutableString alloc] init];
    
    for (NSString *string in self.activityItems){
        //附加字符串
        [reversedStrings appendString:[self reverseOfString:string]];
        //换行
        [reversedStrings appendString:@"n"];
    }
    
    //创建弹出 警告
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Reversed" message:reversedStrings
                                                       delegate:self
                                              cancelButtonTitle:@"OK"
                                              otherButtonTitles:nil];
    
    [alertView show];
    
}

@end

@implementation ViewController

- (void) viewDidAppear:(BOOL)animated{
    [super viewDidAppear:animated];
    
    //创建item数组
    NSArray *itemsToShare = @[@"Item 1", @"Item 2", @"Item 3"];
    
    //创建activity，进入view直接弹出
    UIActivityViewController *activity = [[UIActivityViewController alloc]initWithActivityItems:itemsToShare applicationActivities:@[[StringReverserActivity new]]];
    
    //modal弹出
    [self presentViewController:activity animated:YES completion:nil];
}

@end