我正在使用Autolayout Progrmatically创建UiScrollview和UIPagectontrol的应用程序
我创建了TKScroller作为UIView的子类,我使用一些模式和数组来初始化它.
TKScroller.m
-(void)setData{
[self layoutIfNeeded];
CGRect mainFrame=self.frame;
[self layoutIfNeeded];
CGRect mainFrame=self.frame;
UIView *lastview;
NSMutableArray* manualConstraints = [NSMutableArray array];
for (int i=0; i<arrayData.count ; i++)
{
CGRect frame;
frame.origin.x = scrollView.frame.size.width * i;
frame.origin.y = 0;
frame.size = scrollView.frame.size;
UIView *subview = [UIView new];
subview.backgroundColor = [self getRandomColor];
[scrollView addSubview:subview];
if (i==0)
{
NSLayoutConstraint* b1_top = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeTop multiplier:1 constant:5];
[manualConstraints addObject:b1_top];
NSLayoutConstraint* b1_left = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeLeading multiplier:1 constant:5];
[manualConstraints addObject:b1_left];
NSLayoutConstraint* b1_right = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeTrailing multiplier:1 constant:-5];
[manualConstraints addObject:b1_right];
NSLayoutConstraint* b1_bottom = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeTop multiplier:1 constant:-10];
[manualConstraints addObject:b1_bottom];
[subview layoutIfNeeded];
[scrollView addConstraints:manualConstraints];
lastview=subview;
}
else{
NSLayoutConstraint* b1_top = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeTop multiplier:1 constant:5];
[manualConstraints addObject:b1_top];
NSLayoutConstraint* b1_left = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:lastview attribute:NSLayoutAttributeLeading multiplier:1 constant:5];
[manualConstraints addObject:b1_left];
NSLayoutConstraint* b1_right = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeTrailing multiplier:1 constant:-5];
[manualConstraints addObject:b1_right];
NSLayoutConstraint* b1_bottom = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:scrollView attribute:NSLayoutAttributeTop multiplier:1 constant:-10];
[manualConstraints addObject:b1_bottom];
[subview layoutIfNeeded];
[scrollView addConstraints:manualConstraints];
lastview=subview;
}
}
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * arrayData.count,mainFrame.size.height/2);
self.pageControl.currentPage = 0;
self.pageControl.numberOfPages = arrayData.count;
pageControlBeingUsed = NO;
}
-(UIColor *)getRandomColor{
int r = arc4random() % 255;
int g = arc4random() % 255;
int b = arc4random() % 255;
return [UIColor colorWithRed:(r/255.0) green:(g/255.0) blue:(b/255.0) alpha:1.0];
}
现在我得到任何子视图,
但是如果我改变方向会给出不正确的结果,那么我如何给NSLayoutConstraint的scrollview子视图？
编辑
添加NSLayoutConstraint子视图后不会显示.我只是错过了一些约束,请在动态设置约束时纠正我.
我的Source Code is here,请帮我
谢谢.对不起,糟糕的语法.
解决方法
Here is a SO answer已经解释了如何做到这一点与汽车布局,他已经解释完美,在这里有垂直的textfields在那里但在你的情况下,你必须设置水平视图约束.
替代
而是设置约束,您可以设置子视图的框架,并将其设置在ScrollView中,并且根据方向,您可以更改scrolview的子视图的框架.
你的setData方法就像,
-(void)setData{
[self layoutIfNeeded];
CGRect mainFrame=scrollView.frame;
CGRect frame;
for (int i=0; i<arrayData.count ; i++)
{
CGRect frame;
frame.origin.x = scrollView.frame.size.width * i;
frame.origin.y = 0;
frame.size = scrollView.frame.size;
frame.origin=CGPointMake(0,0);
UIView *subview = [[UIView alloc]initWithFrame:frame];
subview.backgroundColor = [self getRandomColor];
[scrollView addSubview:subview];
}
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * arrayData.count,mainFrame.size.height/2);
}
现在你使用NSNotificationCenter可以在设备方向被通知时得到通知,所以在这种选择器方法中,它调用你的setData方法,
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(setData)
name:UIDeviceOrientationDidChangeNotification
object:nil];
现在在您的setData方法中,您需要删除所有子视图,因为当设备更改Orientation时,它将向scrollview添加新视图,因此在设置其框架之前,从Scrollview中删除所有子视图,
[scrollView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
确保你从你的类中删除观察者,
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
