width怎么往某一方向展开

OCer commented 6 years ago

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Issue Info

Info	Value
Platform	ios
Platform Version	10.0
Masonry Version	1.0
Integration Method	manually

Issue Description

我用mansory做动画，很简单，就改变宽度 [self mas_updateConstraints:^(MASConstraintMaker make) { [make width].mas_equalTo(BLSelectableButtonWidth self.items.count); }];

但是，这个动画并不理想，我想要的是x不变，width往某一方向展开。但事实上是，width在中心点同时往2边展开，这就导致了在做动画的时候，x出现偏移的视觉效果（因为约束的关系，事实上在做动画前width已经确定了，而width是2边展开的，为了x不变，所以view在调整x）。

Eflet commented 6 years ago

再限定下left啊， [make left].mas_equalTo

KelaKing commented 6 years ago

如果约束都正确的话调 [self.superview layoutIfNeed] 而不是 [self layoutIfNeed]

OCer commented 6 years ago

怎么说？如果self是父控件，那要刷新添加到它上面的view，不应该是 [self layoutIfNeed]？？ @KelaKing

KelaKing commented 6 years ago

如果只调 [self layoutIfNeed], 布局引擎会计算width变化，但对父视图的约束没有计算（比如说与父视图左对齐）,导致动画 block 中 frame 计算不准确 @OCer

OCer commented 6 years ago

我父控件的大小是已经定了的不再改变

zwind007 commented 6 years ago

I have came across the same problem.

zwind007 commented 6 years ago

问题已经解决，关键在这句 [self.progressBarView.superview.superview layoutIfNeeded];

[self.progressWidthConstraint uninstall];
[self.progressBarView mas_makeConstraints:^(MASConstraintMaker *make) {
     self.progressWidthConstraint = make.width.equalTo(self.progressBarTraceView).multipliedBy(self.progress);
}];
[UIView animateWithDuration:1.0 animations:^{
     [self.progressBarView.superview.superview layoutIfNeeded];
}];

SnapKit / Masonry