UIActivityViewController分享时禁用微信

iOS使用UIActivityViewController可以调起系统自带的分享功能，但是系统自带的微信分享不支持纯文字分享，可以用以下方式将微信分享屏蔽掉：

@interface UIActivityViewController (Private)
- (BOOL)_shouldExcludeActivityType:(UIActivity*)activity;
@end

@interface MyActivityViewController : UIActivityViewController
@end

@implementation MyActivityViewController
- (BOOL)_shouldExcludeActivityType:(UIActivity *)activity
{
    if ([[activity activityType] isEqualToString:@"com.tencent.xin.sharetimeline"]) 
    {
        return YES;
    }
    return [super _shouldExcludeActivityType:activity];
}
@end

参考How to exclude Notes and Reminders apps from the UIActivityViewController?