在顶部/导航栏中放置一个 SearchBar [英] Placing a SearchBar in the top/navigation bar

问题描述

在 Forms 项目中，是否可以放置 SearchBar 使其出现在应用程序的顶部/导航栏中?我想要实现的是与 Android Youtube 应用程序类似的东西，只是跨平台:

解决方案

为此，您应该为您的页面编写渲染器

有我的 iOS 实现(带有自定义searchField")

使用CoreGraphics；使用基金会；使用我的控件；使用 MyRenderer；使用 UIKit；使用 Xamarin.Forms；[组装:ExportRenderer(typeof(MySearchContentPage), typeof(MySearchContentPageRenderer))]命名空间 IOS.Renderer{使用 Xamarin.Forms.Platform.iOS；公共类 MySearchContentPageRenderer : PageRenderer{公共覆盖无效 ViewWillAppear(布尔动画){base.ViewWillAppear(动画)；SetSearchToolbar();}公共覆盖无效 WillMoveToParentViewController(UIKit.UIViewController parent){base.WillMoveToParentViewController(parent);如果(父母！= null){parent.NavigationItem.RightBarButtonItem = NavigationItem.RightBarButtonItem;parent.NavigationItem.TitleView = NavigationItem.TitleView;}}私有无效 SetSearchToolbar(){var element = Element as MySearchContentPage;如果(元素==空){返回;}var width = NavigationController.NavigationBar.Frame.Width;var height = NavigationController.NavigationBar.Frame.Height;var searchBar = new UIStackView(new CGRect(0, 0, width * 0.85, height));searchBar.Alignment = UIStackViewAlignment.Center;searchBar.Axis = UILayoutConstraintAxis.Horizo​​ntal;searchBar.Spacing = 3;var searchTextField = new MyUITextField();searchTextField.BackgroundColor = UIColor.FromRGB(239, 239, 239);NSAttributedString strAttr = new NSAttributedString("Search", foregroundColor: UIColor.FromRGB(146, 146, 146));searchTextField.AttributedPlaceholder = strAttr;searchTextField.SizeToFit();//删除按钮UIButton textDeleteButton = new UIButton(new CGRect(0, 0, searchTextField.Frame.Size.Height + 5, searchTextField.Frame.Height));textDeleteButton.Font = UIFont.FromName("FontAwesome", 18f);textDeleteButton.BackgroundColor = UIColor.Clear;textDeleteButton.SetTitleColor(UIColor.FromRGB(146, 146, 146), UIControlState.Normal);textDeleteButton.SetTitle("uf057", UIControlState.Normal);textDeleteButton.TouchUpInside += (sender, e) =>{searchTextField.Text = string.Empty;};searchTextField.RightView = textDeleteButton;searchTextField.RightViewMode = UITextFieldViewMode.Always;//边界searchTextField.BorderStyle = UITextBorderStyle.RoundedRect;searchTextField.Layer.BorderColor = UIColor.FromRGB(239, 239, 239).CGColor;searchTextField.Layer.BorderWidth = 1;searchTextField.Layer.CornerRadius = 5;searchTextField.EditingChanged += (sender, e) =>{element.SetValue(MySearchContentPage.SearchTextProperty, searchTextField.Text);};searchBar.AddArrangedSubview(searchTextField);var searchbarButtonItem = new UIBarButtonItem(searchBar);NavigationItem.SetRightBarButtonItem(searchbarButtonItem, true);NavigationItem.TitleView = new UIView();如果(ParentViewController ！= null){ParentViewController.NavigationItem.RightBarButtonItem = NavigationItem.RightBarButtonItem;ParentViewController.NavigationItem.TitleView = NavigationItem.TitleView;}}}}

另外，还有一些讨论:

我希望你理解了主要思想.

In a Forms project, is it possible to place a SearchBar such that it appears in the top/navigation bar of the app? What I want to achieve is something along the lines of the Android Youtube app, just cross-platform:

解决方案

To do this, you should write a renderer for your Page

There is my implementation for iOS (with custom 'searchField')

using CoreGraphics;
using Foundation;
using MyControls;
using MyRenderer;
using UIKit;
using Xamarin.Forms;

[assembly: ExportRenderer(typeof(MySearchContentPage), typeof(MySearchContentPageRenderer))]

namespace IOS.Renderer
{
    using Xamarin.Forms.Platform.iOS;

    public class MySearchContentPageRenderer : PageRenderer
    {
        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);

            SetSearchToolbar();
        }

        public override void WillMoveToParentViewController(UIKit.UIViewController parent)
        {
            base.WillMoveToParentViewController(parent);

            if (parent != null)
            {
                parent.NavigationItem.RightBarButtonItem = NavigationItem.RightBarButtonItem;
                parent.NavigationItem.TitleView = NavigationItem.TitleView;
            }
        }

        private void SetSearchToolbar()
        {
            var element = Element as MySearchContentPage;
            if (element == null)
            {
                return;
            }

            var width = NavigationController.NavigationBar.Frame.Width;
            var height = NavigationController.NavigationBar.Frame.Height;
            var searchBar = new UIStackView(new CGRect(0, 0, width * 0.85, height));

            searchBar.Alignment = UIStackViewAlignment.Center;
            searchBar.Axis = UILayoutConstraintAxis.Horizontal;
            searchBar.Spacing = 3;

            var searchTextField = new MyUITextField();
            searchTextField.BackgroundColor = UIColor.FromRGB(239, 239, 239);
            NSAttributedString strAttr = new NSAttributedString("Search", foregroundColor: UIColor.FromRGB(146, 146, 146));
            searchTextField.AttributedPlaceholder = strAttr;
            searchTextField.SizeToFit();

            // Delete button
            UIButton textDeleteButton = new UIButton(new CGRect(0, 0, searchTextField.Frame.Size.Height + 5, searchTextField.Frame.Height));
            textDeleteButton.Font = UIFont.FromName("FontAwesome", 18f);
            textDeleteButton.BackgroundColor = UIColor.Clear;
            textDeleteButton.SetTitleColor(UIColor.FromRGB(146, 146, 146), UIControlState.Normal);
            textDeleteButton.SetTitle("uf057", UIControlState.Normal);
            textDeleteButton.TouchUpInside += (sender, e) => 
            {
                searchTextField.Text = string.Empty;
            };

            searchTextField.RightView = textDeleteButton;
            searchTextField.RightViewMode = UITextFieldViewMode.Always;

            // Border
            searchTextField.BorderStyle = UITextBorderStyle.RoundedRect;
            searchTextField.Layer.BorderColor = UIColor.FromRGB(239, 239, 239).CGColor;
            searchTextField.Layer.BorderWidth = 1;
            searchTextField.Layer.CornerRadius = 5;
            searchTextField.EditingChanged += (sender, e) => 
            { 
                element.SetValue(MySearchContentPage.SearchTextProperty, searchTextField.Text);
            };

            searchBar.AddArrangedSubview(searchTextField);

            var searchbarButtonItem = new UIBarButtonItem(searchBar);
            NavigationItem.SetRightBarButtonItem(searchbarButtonItem, true);

            NavigationItem.TitleView = new UIView();

            if (ParentViewController != null)
            {
                ParentViewController.NavigationItem.RightBarButtonItem = NavigationItem.RightBarButtonItem;
                ParentViewController.NavigationItem.TitleView = NavigationItem.TitleView;
            }
        }
    }
}

Also, there is some discussion:How to include view in NavigationBar of Xamarin Forms?

I hope, you understood the main idea.

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