【发布时间】：2015-03-20 16:02:03
【问题描述】：
假设我有一个 ViewController，上面有一个 UICollectionView。如何让 Touches 通过 UICollectionView 并进入 ViewController 的 TouchesBegan/TouchesMoved/TouchesEnded 函数？我已经多次使用UIScrollViews 完成此操作，只需设置ExclusiveTouch = false，然后允许触摸通过UIScrollView 到达它的超级视图。但同样的方法不适用于UICollectionViews。有任何想法吗？
设置好了UICollectionView:
partial class CyanViewController : BaseViewControllerWithCollection
{
/*--------------------------------------------------------------------------------*/
// Constructors
/*--------------------------------------------------------------------------------*/
public CyanViewController (IntPtr handle) : base (handle)
{
}
/*--------------------------------------------------------------------------------*/
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
// Setup collection view
this.SetupCollectionView();
}
/*--------------------------------------------------------------------------------*/
public override void TouchesBegan (NSSet touches, UIEvent evt)
{
base.TouchesBegan (touches, evt);
Console.WriteLine ("TouchesBegan");
}
/*--------------------------------------------------------------------------------*/
// Private Methods
/*--------------------------------------------------------------------------------*/
private void SetupCollectionView ()
{
Console.WriteLine ("SetupCollectionView");
try
{
// Instantiate collection view
this.CollectionView = new UICollectionView(
this.View.Bounds,
new UICollectionViewFlowLayout() {
ScrollDirection = UICollectionViewScrollDirection.Vertical,
ItemSize = new CGSize(75, 115),
SectionInset = new UIEdgeInsets(20, 20, 20, 20)
}
);
// Setup delegate and data source
this.CollectionView.Delegate = new ProductTypeCollectionViewDelegate(this);
this.CollectionView.DataSource = new ProductTypeCollectionViewDataSource(this);
this.CollectionView.RegisterClassForCell(typeof(BaseCollectionViewCell), BaseCollectionViewCell.s_millaCellId);
}
catch (Exception ex)
{
Console.WriteLine ("Exception : " + ex.Message);
Console.WriteLine ("Exception : " + ex.StackTrace);
}
// Add collection view to view
this.View.AddSubview(this.CollectionView);
}
/*--------------------------------------------------------------------------------*/
// Class: SeedsCollectionViewDataSource
/*--------------------------------------------------------------------------------*/
public class ProductTypeCollectionViewDataSource : UICollectionViewDataSource
{
/*--------------------------------------------------------------------------------*/
// Properties
/*--------------------------------------------------------------------------------*/
private CyanViewController _parentController;
/*--------------------------------------------------------------------------------*/
// Constructors
/*--------------------------------------------------------------------------------*/
public ProductTypeCollectionViewDataSource (
CyanViewController a_parentController
)
{
this._parentController = a_parentController;
}
/*--------------------------------------------------------------------------------*/
private ProductTypeCollectionViewDataSource ()
{
throw new NotImplementedException ();
}
/*--------------------------------------------------------------------------------*/
// UICollectionViewDataSource Implementation
/*--------------------------------------------------------------------------------*/
public override UICollectionViewCell GetCell (UICollectionView collectionView, NSIndexPath indexPath)
{
var cell = (BaseCollectionViewCell)collectionView.DequeueReusableCell (BaseCollectionViewCell.s_millaCellId, indexPath);
cell.Label.Text = "Woot";
return cell;
}
/*--------------------------------------------------------------------------------*/
public override nint GetItemsCount (UICollectionView collectionView, nint section)
{
return 10;
}
/*--------------------------------------------------------------------------------*/
}
/*--------------------------------------------------------------------------------*/
// Class: SeedsCollectionViewDelegate
/*--------------------------------------------------------------------------------*/
public class ProductTypeCollectionViewDelegate : UICollectionViewDelegate
{
/*--------------------------------------------------------------------------------*/
// Properties
/*--------------------------------------------------------------------------------*/
private CyanViewController _parentController;
/*--------------------------------------------------------------------------------*/
// Constructors
/*--------------------------------------------------------------------------------*/
public ProductTypeCollectionViewDelegate (
CyanViewController a_parentController
)
{
this._parentController = a_parentController;
}
/*--------------------------------------------------------------------------------*/
private ProductTypeCollectionViewDelegate ()
{
throw new NotImplementedException ();
}
/*--------------------------------------------------------------------------------*/
// UICollectionViewDelegate Implementation
/*--------------------------------------------------------------------------------*/
public async override void ItemSelected (UICollectionView collectionView, NSIndexPath indexPath)
{
Console.WriteLine ("ItemSelected indexPath.Row = " + indexPath.Row);
}
/*--------------------------------------------------------------------------------*/
}
/*--------------------------------------------------------------------------------*/
}
设置拥有CollectionView 的UIViewController。我想在这里联系TouchesBegan/Moved/Ended！
partial class BaseViewControllerWithCollection : UIViewController
{
/*--------------------------------------------------------------------------------*/
// Properties
/*--------------------------------------------------------------------------------*/
public UICollectionView CollectionView { get; set; }
/*--------------------------------------------------------------------------------*/
// Constructors
/*--------------------------------------------------------------------------------*/
public BaseViewControllerWithCollection (IntPtr handle) : base (handle)
{
this.View.ExclusiveTouch = false;
this.View.UserInteractionEnabled = true;
}
public override void TouchesBegan (NSSet touches, UIEvent evt)
{
base.TouchesBegan (touches, evt);
Console.WriteLine ("TouchesBegan");
}
public override void TouchesMoved (NSSet touches, UIEvent evt)
{
base.TouchesMoved (touches, evt);
Console.WriteLine ("TOuchesMoved");
}
public override void TouchesEnded (NSSet touches, UIEvent evt)
{
base.TouchesEnded (touches, evt);
Console.WriteLine ("TouchesSended");
}
/*--------------------------------------------------------------------------------*/
}
这是我的UICollectionView 班级。我无法在UIViewController 中获得联系，所以我尝试将它们带到这里，但无法....
public class MyCollectionView : UICollectionView
{
public MyCollectionView ( CGRect frame, UICollectionViewLayout layout ) : base (frame, layout)
{
this.ExclusiveTouch = false;
this.UserInteractionEnabled = true;
this.BackgroundView.UserInteractionEnabled = true;
this.BackgroundView.ExclusiveTouch = false;
}
public override void TouchesBegan (NSSet touches, UIEvent evt)
{
base.TouchesBegan (touches, evt);
Console.WriteLine ("MyCollectionVIew TouchesBegan");
}
public override void TouchesMoved (NSSet touches, UIEvent evt)
{
base.TouchesMoved (touches, evt);
Console.WriteLine ("MyCollectionVIew TouchesMoved");
}
public override void TouchesEnded (NSSet touches, UIEvent evt)
{
base.TouchesEnded (touches, evt);
Console.WriteLine ("MyCollectionVIew TouchesEnded");
}
}
【问题讨论】：
-
你是想让集合视图和底层视图都识别触摸，还是只被底层视图识别？
-
我希望 collectionview 能够正常工作，但是当您只需点击或按住并拖动以获取底层视图来捕获 TouchesBegan/Moved/Ended 时。所以可能两者兼而有之。 UIScrollViews 两者都可以，所以我试图弄清楚为什么 UICollectionViews 不能。或者如果他们能，他们怎么能？
标签： ios uiscrollview xamarin.ios xamarin uicollectionview