当我尝试启动我正在使用的应用程序时收到以下错误。 '常数不是有限的!那是非法的。常量:nan'
这是 Instagram 的学校项目克隆。我认为错误出在 subview 中或可能在创建的约束中,但不幸的是我只是没有看到问题。
- (void) layoutSubviews {
[super layoutSubviews];
// Before layout, calculate the intrinsic size of the labels (the size they "want" to be), and add 20 to the height for some vertical padding.
CGSize maxSize = CGSizeMake(CGRectGetWidth(self.bounds), CGFLOAT_MAX);
CGSize usernameLabelSize = [self.usernameAndCaptionLabel sizeThatFits:maxSize];
CGSize commentLabelSize = [self.commentLabel sizeThatFits:maxSize];
self.usernameAndCaptionLabelHeightConstraint.constant = usernameLabelSize.height + 20;
self.commentLabelHeightConstraint.constant = commentLabelSize.height + 20;
self.imageHeightConstraint.constant = self.mediaItem.image.size.height / self.mediaItem.image.size.width * CGRectGetWidth(self.contentView.bounds);
// Hide the line between cells
self.separatorInset = UIEdgeInsetsMake(0, 0, 0, CGRectGetWidth(self.bounds));
}
NSDictionary *viewDictionary = NSDictionaryOfVariableBindings(_mediaImageView, _usernameAndCaptionLabel, _commentLabel);
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[_mediaImageView]|" options:kNilOptions metrics:nil views:viewDictionary]];
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[_usernameAndCaptionLabel]|" options:kNilOptions metrics:nil views:viewDictionary]];
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[_commentLabel]|" options:kNilOptions metrics:nil views:viewDictionary]];
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[_mediaImageView][_usernameAndCaptionLabel][_commentLabel]" options:kNilOptions metrics:nil views:viewDictionary]];
self.imageHeightConstraint = [NSLayoutConstraint constraintWithItem:_mediaImageView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:100];
self.imageHeightConstraint.identifier = @"Image height constraint";
self.usernameAndCaptionLabelHeightConstraint = [NSLayoutConstraint constraintWithItem:_usernameAndCaptionLabel attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:100];
self.usernameAndCaptionLabelHeightConstraint.identifier = @"Username and caption label height constraint";
self.commentLabelHeightConstraint = [NSLayoutConstraint constraintWithItem:_commentLabel attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:100];
self.commentLabelHeightConstraint.identifier = @"Comment label height constraint";
[self.contentView addConstraints:@[self.imageHeightConstraint, self.usernameAndCaptionLabelHeightConstraint, self.commentLabelHeightConstraint]];
}
最佳答案
我只看到一个地方你在做除法:
self.imageHeightConstraint.constant = self.mediaItem.image.size.height / self.mediaItem.image.size.width * CGRectGetWidth(self.contentView.bounds);
在这一行打个断点,看看self.mediaItem.image.size
是什么样子的。
关于ios - '常数不是有限的!那是非法的。常量 :nan' error in Objective C,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30157028/