[英]How to put a white line between two calls to Console.WriteLine()?
[英]How to put a constraint between a UILabel and two UIImageView?
我正在尝试使用 2 个图像和一个标签制作一个水平的 UIStackView:
我想要实现的是这样的(蓝色的选定元素):
这是我的代码:
public partial class ViewController : UIViewController
{
public ViewController(IntPtr handle) : base(handle)
{
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
UIStackView header = new UIStackView();
header.Axis = UILayoutConstraintAxis.Horizontal;
View.AddSubview(header);
//< color name = "healthy_green" >#409900</color>
var healthy_green = new UIColor(red: 0.25f, green: 0.60f, blue: 0.00f, alpha: 1.00f);
//< color name = "optimistic_orange" >#FF5F00</color>
var optimistic_orange = new UIColor(red: 1.00f, green: 0.37f, blue: 0.00f, alpha: 1.00f);
// Enable Auto Layout
header.TranslatesAutoresizingMaskIntoConstraints = false;
var ic_qol_image = UIImage.FromBundle("ic_qol");
ic_qol_image.ApplyTintColor(healthy_green);
var ic_qol = new UIImageView(ic_qol_image);
ic_qol.SizeToImage();
var qol_title = new UILabel { TranslatesAutoresizingMaskIntoConstraints = false, Text = @"Quality of Life" };
var ic_edit_image = UIImage.FromBundle("ic_edit");
ic_edit_image.ApplyTintColor(optimistic_orange);
var ic_edit = new UIImageView(ic_edit_image);
ic_edit.SizeToImage();
var qolHeaderViews = new UIView[] { ic_qol, qol_title, ic_edit };
header.AddSubviews(qolHeaderViews);
header.Anchor(top: View.SafeAreaLayoutGuide.TopAnchor, leading: View.LeadingAnchor, trailing: View.TrailingAnchor);
ic_qol.Anchor(top: header.TopAnchor, leading: header.LeadingAnchor);
ic_edit.Anchor(top: header.TopAnchor, trailing: header.TrailingAnchor);
qol_title.Anchor(top: View.SafeAreaLayoutGuide.TopAnchor, leading: ic_qol.RightAnchor, trailing: ic_edit.RightAnchor, padding: new UIEdgeInsets(0, 10, 0, 0)); <=== fails here.
}
public override void DidReceiveMemoryWarning()
{
base.DidReceiveMemoryWarning();
// Release any cached data, images, etc that aren't in use.
}
}
internal static class extensions
{
// https://stackoverflow.com/a/48601685/15186
internal static void SizeToImage(this UIImageView uIImageView)
{
//Grab loc
var xC = uIImageView.Center.X;
var yC = uIImageView.Center.Y;
//Size to fit
uIImageView.Frame = new CGRect(x: 0, y: 0, width: uIImageView.Image.Size.Width / 2, height: uIImageView.Image.Size.Height / 2);
//Move to loc
uIImageView.Center = new CGPoint(x: xC, y: yC);
}
internal static void FillParentView(this UIView uIView)
{
uIView.Anchor(top: uIView.Superview?.TopAnchor, leading: uIView.Superview?.LeadingAnchor, bottom: uIView.Superview?.BottomAnchor, trailing: uIView.Superview.TrailingAnchor);
}
internal static void AnchorSize(this UIView uIView, UIView to)
{
uIView.WidthAnchor.ConstraintEqualTo(to.WidthAnchor).Active = true;
uIView.HeightAnchor.ConstraintEqualTo(to.HeightAnchor).Active = true;
}
internal static void Anchor(this UIView uIView, NSLayoutYAxisAnchor top = null, NSLayoutXAxisAnchor leading = null, NSLayoutYAxisAnchor bottom = null, NSLayoutXAxisAnchor trailing = null, UIEdgeInsets padding = default, CGSize size= default)
{
uIView.TranslatesAutoresizingMaskIntoConstraints = false;
if (top != null)
{
uIView.TopAnchor.ConstraintEqualTo(top, padding.Top).Active = true;
}
if (leading != null)
{
uIView.LeadingAnchor.ConstraintEqualTo(leading, padding.Left).Active = true; <=== fails here.
}
if (bottom != null)
{
uIView.BottomAnchor.ConstraintEqualTo(bottom, -padding.Bottom).Active = true;
}
if (trailing != null)
{
uIView.TrailingAnchor.ConstraintEqualTo(trailing, -padding.Right).Active = true;
}
if ( size.Width != 0)
{
uIView.WidthAnchor.ConstraintEqualTo(size.Width).Active = true;
}
if ( size.Height != 0)
{
uIView.HeightAnchor.ConstraintEqualTo(size.Height).Active = true;
}
}
}
我试图将标签的前导锚点约束到图像的尾随锚点,但由于以下异常而失败:
A constraint cannot be made between <NSLayoutXAxisAnchor:0x280bcb980 "UILabel:0x1015132a0'Quality of Life'.leading">' and '<NSLayoutXAxisAnchor:0x280bcb840 "UIImageView:0x101510ea0.right">' because their units are not compatible.
我知道他们的单位可能不兼容,但无论如何我该怎么做? 如何使单位兼容?
致谢:我使用的扩展方法最初是在本视频教程中创建的。 我将它们移植到 c#。
您可以使用“水平”堆栈视图轻松实现此布局。
注意:我不使用 xamarin/c#,所以我只会描述你想要做什么。
header.AddArrangedSubview(ic_qol);
header.AddArrangedSubview(qol_title);
header.AddArrangedSubview(ic_edit);
View.AddSubview(header);
最后一步是添加约束以将堆栈视图放在顶部,跨越视图的宽度:
// Get the parent view's layout
var margins = View.LayoutMarginsGuide;
// Pin the top edge of the stackView to the margin
header.TopAnchor.ConstraintEqualTo (margins.TopAnchor).Active = true;
// Pin the leading edge of the stackView to the margin
header.LeadingAnchor.ConstraintEqualTo (margins.LeadingAnchor).Active = true;
// Pin the trailing edge of the stackView to the margin
header.TrailingAnchor.ConstraintEqualTo (margins.TrailingAnchor).Active = true;
结果应该是这样的:
每个 imageView 被限制为 40 pts 宽度和高度等于宽度。 标签有青色背景,便于查看布局,文字居中对齐。 轮廓就在那里,所以我们可以看到 stackView 的框架。
在运行时,没有框架轮廓:
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