CPF netcore跨平台UI框架
系列教程
CPF 入門教程 - 數據綁定和命令綁定（二）
數據綁定和Wpf類似，支持雙向綁定。數據綁定和命令綁定是UI和業務邏輯分離的基礎。
首先，你需要定義個MainModel，為了可以有屬性通知，這個類可以繼承CpfObject或者自己實現INotifyPropertyChanged
1 public class MainModel : CpfObject 2 { 3 [PropertyMetadata("默認值")] 4 public string Test 5 { 6 get { return (string)GetValue(); } 7 set { SetValue(value); } 8 } 9 }
這里定義了一個Test屬性，並且設置默認值為“默認值”
設計個測試界面，加個TextBlock和Button，同時TextBlock設置綁定，綁定定義在Bindings屬性， {nameof(TextBlock.Text),nameof(MainModel.Test) } 表示TextBlock的Text綁定到DataContext的Test屬性
public class Window4 : Window { protected override void InitializeComponent() { Title = "標題"; Width = 344.8f; Height = 126.4f; Background = null; Children.Add(new WindowFrame(this, new Panel { Width = "100%", Height = "100%", Children = { //內容元素放這里 new Button { MarginLeft = 223.8f, MarginTop = 25.7f, Height = 28f, Width = 67.4f, Content = "Button", }, new TextBlock { MarginLeft = 36.7f, MarginTop = 31.6f, Text = "TextBlock", Bindings = { {nameof(TextBlock.Text),nameof(MainModel.Test) } } }, } })); LoadStyleFile("res://ConsoleApp1/Stylesheet1.css"); //加載樣式文件，文件需要設置為內嵌資源 } }
修改program，設置Window的DataContext和CommandContext
var model = new MainModel(); Application.Run(new Window4 { DataContext = model, CommandContext = model });
寫好之后，運行看看效果。TextBlock那邊顯示MainModel那邊定義的默認值
接下來定義命令，通過按鈕點擊修改Test值，同時自動更新到TextBlock
MainModel里增加個Click方法
class MainModel : CpfObject { [PropertyMetadata("默認值")] public string Test { get { return (string)GetValue(); } set { SetValue(value); } } public void Click() { Test += "test"; } }
Button那邊增加命令綁定，Commands里添加， {nameof(Button.Click),nameof(MainModel.Click) } 表示Button的Click事件綁定到CommandContext的Click方法
new Button { MarginLeft = 223.8f, MarginTop = 25.7f, Height = 28f, Width = 67.4f, Content = "Button", Commands = { {nameof(Button.Click),nameof(MainModel.Click) } } },
運行效果，點擊一次增加一次test。這就是最簡單的模型視圖分離的數據綁定
接下來綁定集合
設計界面，添加Button和ListBox
往MainModel里加上Items集合屬性，構造函數里初始化集合，用 Collection 是為了有集合變化通知，也可以使用 ObservableCollection。 (string, string) 就是元組里簡化的結構體類型定義，是一種偷懶簡化數據定義的方式，不過這種方式的話，改item就不能更新到UI了，需要可以更新到UI的就需要自定義類型，繼承CpfObject或者繼承INotifyPropertyChanged的類型作為Item
public MainModel() { Items = new Collection<(string, string)>(); } public Collection<(string,string)> Items { get { return (Collection<(string, string)>)GetValue(); } set { SetValue(value); } }
MainModel里加個AddItem方法
public void AddItem() { Items.Add(("test" + Items.Count, Items.Count.ToString())); }
最終代碼
using CPF; using System; using System.Collections.Generic; using System.Text; namespace ConsoleApp1 { class MainModel : CpfObject { [PropertyMetadata("默認值")] public string Test { get { return (string)GetValue(); } set { SetValue(value); } } public void Click() { Test += "test"; } public MainModel() { Items = new Collection<(string, string)>(); } public Collection<(string, string)> Items { get { return (Collection<(string, string)>)GetValue(); } set { SetValue(value); } } public void AddItem() { Items.Add(("test" + Items.Count, Items.Count.ToString())); } } }
using System; using System.Collections.Generic; using System.Linq; using System.Text; using CPF; using CPF.Drawing; using CPF.Controls; using CPF.Shapes; using CPF.Styling; using CPF.Animation; namespace ConsoleApp1 { public class Window4 : Window { protected override void InitializeComponent() { Title = "標題"; Width = 338.4f; Height = 205.6f; Background = null; Children.Add(new WindowFrame(this, new Panel { Width = "100%", Height = "100%", Children = { //內容元素放這里 new Button { MarginLeft = 223.8f, MarginTop = 25.7f, Height = 28f, Width = 67.4f, Content = "Button", Commands = { { nameof(Button.Click), nameof(MainModel.Click) } } }, new TextBlock { MarginLeft = 36.7f, MarginTop = 31.6f, Text = "TextBlock", Bindings = { { nameof(TextBlock.Text), nameof(MainModel.Test) } } }, new Button { MarginLeft = 223.8f, MarginTop = 91.6f, Height = 28f, Width = 67.4f, Content = "添加Item", Commands = { {nameof(Button.Click),nameof(MainModel.AddItem) } } }, new ListBox { SelectedValuePath = "Item2",//綁定Item里的Item1屬性 DisplayMemberPath = "Item1",//綁定Item里的Item2屬性 BorderStroke = "1,Solid", BorderFill = "#DEDEDE", MarginLeft = 36.7f, MarginTop = 60.8f, Height = 76.5f, Width = 123.2f, Bindings = { {nameof(ListBox.Items),nameof(MainModel.Items) } } }, } })); LoadStyleFile("res://ConsoleApp1/Stylesheet1.css"); //加載樣式文件，文件需要設置為內嵌資源 } } }
最終運行效果，點擊添加Item的按鈕，ListBox里會增加Item
數據類型轉換，Test屬性值后面加1。 數據轉換器用方法或者Lambda就行。
{ nameof(TextBlock.Text), nameof(MainModel.Test), null, BindingMode.OneWay, (string a)=>a+"1" }
UI元素之間綁定，TextBox的Text綁定到Button的Content，其中TextBox設置PresenterFor=this,是為了標記TextBox的作用域在當前類，因為Name是可以重復的，元素嵌套如果有相同Name會無法判斷元素是在哪里的，所以用PresenterFor加標記判斷，而且這樣可以通過FindPresenterByName方法來獲取當前類里的標記元素來綁定
protected override void InitializeComponent() { Title = "標題"; Width = 338.4f; Height = 205.6f; Background = null; Children.Add(new WindowFrame(this, new Panel { Width = "100%", Height = "100%", Children = { //內容元素放這里 new Button { MarginLeft = 223.8f, MarginTop = 25.7f, Height = 28f, Width = 67.4f, Content = "Button", Commands = { { nameof(Button.Click), nameof(MainModel.Click) } }, Bindings = { { nameof(Button.Content), nameof(TextBox.Text), FindPresenterByName("textBox") } } }, new TextBlock { MarginLeft = 36.7f, MarginTop = 31.6f, Text = "TextBlock", Bindings = { { nameof(TextBlock.Text), nameof(MainModel.Test), null, BindingMode.OneWay, (string a)=>a+"1" } } }, new Button { MarginLeft = 223.8f, MarginTop = 91.6f, Height = 28f, Width = 67.4f, Content = "添加Item", Commands = { { nameof(Button.Click), nameof(MainModel.AddItem) } } }, new ListBox { SelectedValuePath = "Item2", //綁定Item里的Item1屬性 DisplayMemberPath = "Item1", //綁定Item里的Item2屬性 BorderStroke = "1,Solid", BorderFill = "#DEDEDE", MarginLeft = 36.7f, MarginTop = 60.8f, Height = 76.5f, Width = 123.2f, Bindings = { { nameof(ListBox.Items), nameof(MainModel.Items) } } }, new TextBox { Name="textBox", PresenterFor=this, AcceptsReturn= false, HScrollBarVisibility= ScrollBarVisibility.Hidden, VScrollBarVisibility= ScrollBarVisibility.Hidden, MarginLeft = 144.8f, MarginTop = 28.1f, Width = 74.5f }, } })); LoadStyleFile("res://ConsoleApp1/Stylesheet1.css"); //加載樣式文件，文件需要設置為內嵌資源 }
TextBox輸入，會自動更新Button的文字
命令綁定除了事件之外，屬性變化也可以綁定為命令，比如，鼠標移入和移出就調用
Commands =
{
{
nameof(Button.IsMouseOver),
nameof(MainModel.Click)
}
}
主要綁定就這些，如果要雙向綁定，命令參數等等，看VS那邊的智能提示