2015-01-14 19:10:05.165 mykey_family[14008:4218895] collection:section=4,count=0,newheight=0.000000
2015-01-14 19:10:05.166 mykey_family[14008:4218895] oldHeight=142.500000
2015-01-14 19:10:05.167 mykey_family[14008:4218895] TEST:section = 4, height = 177.000000 （this print in - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath）
2015-01-14 19:10:05.176 mykey_family[14008:4218895] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7f8a4e04f3b0 V:|-(10)-[UIImageView:0x7f8a4e049190] (Names: '|':UITableViewCellContentView:0x7f8a4e048320 )>",
"<NSLayoutConstraint:0x7f8a4e04f430 V:[UIImageView:0x7f8a4e049190(40)]>",
"<NSLayoutConstraint:0x7f8a4e051390 V:[UIImageView:0x7f8a4e049190]-(7)-[UILabel:0x7f8a4e04a950'\U6c5f\U82cf\U53ef\U4e00\U4e0a\U5e02\U4e86\Uff01\U6c5f\U82cf\U53ef\U4e00\U4e0a\U5e02\U4e86\Uff01\U6c5f\U82cf\U53ef\U4e00\U4e0a\U5e02\U4e86\Uff01\U6c5f...']>",
"<NSLayoutConstraint:0x7f8a4e051850 V:[UILabel:0x7f8a4e04a950'\U6c5f\U82cf\U53ef\U4e00\U4e0a\U5e02\U4e86\Uff01\U6c5f\U82cf\U53ef\U4e00\U4e0a\U5e02\U4e86\Uff01\U6c5f\U82cf\U53ef\U4e00\U4e0a\U5e02\U4e86\Uff01\U6c5f...']-(5)-[UILabel:0x7f8a4e04adf0'\U5c55\U5f00\U5168\U6587']>",
"<NSLayoutConstraint:0x7f8a4e051990 V:[UILabel:0x7f8a4e04adf0'\U5c55\U5f00\U5168\U6587'(0)]>",
"<NSLayoutConstraint:0x7f8a4bdbeee0 V:[UILabel:0x7f8a4e04adf0'\U5c55\U5f00\U5168\U6587']-(5)-[UICollectionView:0x7f8a4c0eba00]>",
"<NSLayoutConstraint:0x7f8a4e050e90 V:[UICollectionView:0x7f8a4c0eba00(142.5)]>",
"<NSLayoutConstraint:0x7f8a4e053f00 V:[UICollectionView:0x7f8a4c0eba00]-(8)-[UILabel:0x7f8a4e04d860'55']>",
"<NSLayoutConstraint:0x7f8a4e053f50 V:[UILabel:0x7f8a4e04d860'55']-(12)-| (Names: '|':UITableViewCellContentView:0x7f8a4e048320 )>",
"<NSLayoutConstraint:0x7f8a4bc88900 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x7f8a4e048320(177)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7f8a4e053f00 V:[UICollectionView:0x7f8a4c0eba00]-(8)-[UILabel:0x7f8a4e04d860'55']>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2015-01-14 19:10:05.183 mykey_family[14008:4218895] collection:section=4,count=0,newheight=0.000000
2015-01-14 19:10:05.183 mykey_family[14008:4218895] oldHeight=142.500000
控制器代码：
-(UITableViewCell*)tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSInteger section = [indexPath section];
UITableViewCell *cell = nil;
if (section > [self.classZoneInfo count]) {
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
}
}
else{
ClassZone *info = [self.classZoneInfo objectAtIndex:section];
if (nil != info) {
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifierTextAndImg];
if (cell == nil)
{
cell = [[ClassZoneFullCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifierTextAndImg];
}
ClassZoneFullCell *tempCell = (ClassZoneFullCell *)cell;
[tempCell initCell:info];
}
else{
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
}
}
}
cell.backgroundColor = [UIColor clearColor];
[cell.contentView setBackgroundColor:[UIColor clearColor]];
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
return cell;
}
ClassZoneFullCell.m代码
-(void)updateConstraints
{
[super updateConstraints];
CGRect windowRect = [[UIScreen mainScreen] bounds];
CGFloat width = (windowRect.size.width - (IMG_INNER_WIDTH+IMG_OUTER_WIDTH)*2 - TWO_IMG_SPACE*(MAX_IMG_OF_LINE-1))/4.0f;
if (nil != self.classZone) {
if (self.classZone.imgCount > 4) {
width = (width+TWO_IMG_SPACE/2)*2;
}
else if(0 == self.classZone.imgCount){
width = 0;
}
NSLog(@"collection:section=%ld,count=%ld,newheight=%f",(long)self.classZone.section,self.classZone.imgCount,width);
for (NSLayoutConstraint *c in self.collectionConstraints) {
NSLog(@"oldHeight=%f",c.constant);
c.constant = width;
}
if (self.classZone.more.length > 2) {
if (CLOSE_LINK == self.textType) {
[self.context setNumberOfLines:3];
}
else if (OPEN_LINK == self.textType) {
[self.context setNumberOfLines:0];
}
width = 20.0f;
}
else{
width = 0.0f;
}
for (NSLayoutConstraint *c in self.moreTextConstraints) {
c.constant = width;
}
}
}
- (void)layoutSubviews
{
[super layoutSubviews];
[self.contentView setNeedsLayout];
[self.contentView layoutIfNeeded];
self.context.preferredMaxLayoutWidth = CGRectGetWidth(self.context.frame);
}
- (void)initCell:(ClassZone *)info {
self.classZone = info;
self.timeTitle.text = info.timeTitle;
self.teacher.text = info.teacher;
self.context.text = info.context;
self.moreText.text = info.more;
self.favorCount.text = info.favorCount;
self.commentCount.text = info.commentCount;
self.classZoneImg.tag = info.section;
self.moreText.tag = info.section;
self.textType = info.linkType;
[self setNeedsUpdateConstraints];
[self setNeedsLayout];
}
我的问题：
在updateConstraints（）函数中：我改变了一个视图常量（142.5-> 0），根据异常打印约束是使用旧值，而不是新值（0.0f），所以导致异常，如何解决问题？谢谢！