presentViewController:animated:completion:要比presentModalViewController:好，

ios就推荐用前一个了
两个功能重复，后面的会没掉是肯定的

[[self presentingViewController] dismissModalViewControllerAnimated:YES];
            [[selfpresentingViewController] dismissViewControllerAnimated:YEScompletion:nil];

//[[sharedDialog presentingViewController] dismissModalViewControllerAnimated:YES];
        [[sharedDialogpresentingViewController] dismissViewControllerAnimated:YEScompletion:nil];