我幾個月來一直在使用Xamarin,並且偶爾會遇到一些麻煩。我正在使用自定義渲染器來更改我的選項卡的外觀。在不同標籤之間切換時,它工作得很好。然而,當我瀏覽到我的tabbedPage使用:Xamarin.ios的CustomTabRenderer
Children.Add(new UnitMapPage { Title = "Map", Icon = "map.png" });
CurrentPage = mapPage;
頁打開正確的選項卡上,但TabbarItem的文字看起來酷似非選擇項目。只要你點擊任何標籤,它就會變成正確的樣式。這是我的自定義渲染器。
class CustomTabRenderer : TabbedRenderer
{
private UnitViewModel _unitViewModel;
private TabbedPage _unitPage;
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
if (e.NewElement != null) {
var unitPage = (TabbedPage)e.NewElement;
_unitPage = unitPage;
_unitViewModel = (UnitViewModel)_unitPage.BindingContext;
_unitViewModel.PropertyChanged += OnElementPropertyChanged;
}
// Set Text Font for unselected tab states
UITextAttributes normalTextAttributes = new UITextAttributes();
normalTextAttributes.Font = UIFont.SystemFontOfSize(10.0F, UIFontWeight.Regular); // unselected
normalTextAttributes.TextColor = UIColor.White;
UITabBarItem.Appearance.SetTitleTextAttributes(normalTextAttributes, UIControlState.Normal);
}
void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
if (e.PropertyName == "AlertCount")
{
if (TabBar.Items != null)
{
foreach (var item in TabBar.Items)
{
item.Image = item.Image.ImageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
if (item.Title == "History" && _unitViewModel != null)
{
if (_unitViewModel.AlertCount > 0)
item.BadgeValue = _unitViewModel.AlertCount.ToString();
else
item.BadgeValue = null;
}
}
}
}
}
public override void ViewWillAppear(bool animated)
{
if (TabBar.Items != null)
{
foreach (var item in TabBar.Items)
{
item.Image = item.Image.ImageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
if (item.Title == "History" && _unitViewModel != null)
{
if (_unitViewModel.AlertCount > 0)
item.BadgeValue = _unitViewModel.AlertCount.ToString();
else
item.BadgeValue = null;
}
}
}
base.ViewWillAppear(animated);
}
public override UIViewController SelectedViewController
{
get
{
UITextAttributes selectedTextAttributes = new UITextAttributes();
selectedTextAttributes.Font = UIFont.SystemFontOfSize(12.0F, UIFontWeight.Heavy); // SELECTED
if (base.SelectedViewController != null)
{
base.SelectedViewController.TabBarItem.SetTitleTextAttributes(selectedTextAttributes, UIControlState.Normal);
}
return base.SelectedViewController;
}
set
{
base.SelectedViewController = value;
foreach (UIViewController viewController in base.ViewControllers)
{
UITextAttributes normalTextAttributes = new UITextAttributes();
normalTextAttributes.Font = UIFont.SystemFontOfSize(10.0F, UIFontWeight.Regular); // unselected
normalTextAttributes.TextColor = UIColor.White;
viewController.TabBarItem.SetTitleTextAttributes(normalTextAttributes, UIControlState.Normal);
}
}
}
}
我試過這個,也是在我的自定義渲染器中,但它給了我相同的結果。當我刪除item.Image = item.Image.ImageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal); mapPage圖標是白色的,而另一個是灰色的(表示它被設置爲SelectedIcon),但文本大小與未選中的相同 – Valkyrie