发布于2022年11月4日3年前 项目代码可以从Github下载：https://github.com/zhenl/ZL.Shudu 。代码随项目进度更新。 现在我们增加添加新游戏的功能，创建一个页面，编辑初始局面，并保存到数据库。 我们首先了解一下Xamarin中页面如何跳转。首先，需要为跳转的页面增加路由，这需要在AppShell中增加下面的代码： public AppShell() { InitializeComponent(); Routing.RegisterRoute(nameof(GameEdit), typeof(GameEdit)); Routing.RegisterRoute(nameof(GameList), typeof(GameList)); } GameEdit和GameList是两个页面，GameList中显示数据库中现有的游戏列表，GameEdit用来编辑或新建游戏。通过GameList中的新建游戏按钮或者选择列表中现有的项目，可以跳转到GameEdit。在GameEdit中可以返回到GameList。导航的代码如下： GameList中新建游戏的代码如下： async void btn_NewGame_Clicked(object sender, EventArgs e) { await Shell.Current.GoToAsync($"{nameof(GameEdit)}?{nameof(GameEdit.ItemId)}=0"); } GameList中选中现有项目，跳转到GameEdit的代码如下： async void Handle_ItemTapped(object sender, ItemTappedEventArgs e) { if (e.Item == null) return; await Shell.Current.GoToAsync($"{nameof(GameEdit)}?{nameof(GameEdit.ItemId)}={e.Item}"); } 在GameEdit中，还需要定义接收传入的参数，这里传入的参数是ItemId，在GameEdit的声明中使用QueryProperty标记声明传入参数: [QueryProperty(nameof(ItemId), nameof(ItemId))] [XamlCompilation(XamlCompilationOptions.Compile)] public partial class GameEdit : ContentPage 在接收ItemId时，从数据库中读取相应的记录并初始化页面: public string ItemId { get { return currentId.ToString(); } set { currentId = int.Parse( value); if (currentId > 0) { var game = App.Database.GetGameAsync(currentId).Result; if(game != null) EditGame(game); } } } 下面是GameList和GameEdit的完整代码。 GameList页面代码： <?xml version="1.0" encoding="utf-8" ?> <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:d="http://xamarin.com/schemas/2014/forms" xmlns:d1="http://xamarin.com/schemas/2014/forms/design" x:Class="ZL.Shudu.Views.GameList"> <ContentPage.Content> <StackLayout> <Button Text="新游戏" Clicked="btn_NewGame_Clicked"></Button> <ListView x:Name="MyListView" d1:ItemsSource="{Binding Items}" ItemTapped="Handle_ItemTapped" CachingStrategy="RecycleElement" IsVisible="True"> <d:ListView.ItemsSource> <x:Array Type="{x:Type x:String}"> </x:Array> </d:ListView.ItemsSource> </ListView> </StackLayout> </ContentPage.Content> </ContentPage> GameList后台代码： using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Linq; using System.Text; using System.Threading.Tasks; using Xamarin.Forms; using Xamarin.Forms.Xaml; namespace ZL.Shudu.Views { [XamlCompilation(XamlCompilationOptions.Compile)] public partial class GameList : ContentPage { public ObservableCollection<string> Items { get; set; } public GameList() { InitializeComponent(); } protected override async void OnAppearing() { await RefreshList(); } public async Task RefreshList() { Items = await GetItems(); MyListView.ItemsSource = Items; MyListView.IsVisible = true; } public async Task<ObservableCollection<string>> GetItems() { var items = new ObservableCollection<string>(); var lst = await App.Database.GetGamesAsync(); foreach (var obj in lst) { items.Add(obj.ID.ToString()); } return items; } async void Handle_ItemTapped(object sender, ItemTappedEventArgs e) { if (e.Item == null) return; await Shell.Current.GoToAsync($"{nameof(GameEdit)}?{nameof(GameEdit.ItemId)}={e.Item}"); } async void btn_NewGame_Clicked(object sender, EventArgs e) { await Shell.Current.GoToAsync($"{nameof(GameEdit)}?{nameof(GameEdit.ItemId)}=0"); } } } GameEdit页面代码： <?xml version="1.0" encoding="utf-8" ?> <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="ZL.Shudu.Views.GameEdit"> <ContentPage.Content> <StackLayout> <Grid x:Name="myGrid" IsVisible="True" > <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="25" /> <RowDefinition Height="40" x:Name="rowButton" /> <RowDefinition Height="40" x:Name="rowResult" /> </Grid.RowDefinitions> <Button Text="保存" Grid.Row="9" Grid.Column="2" Grid.ColumnSpan="2" Clicked="btn_Save_Clicked"></Button> <Button Text="删除" x:Name="btn_Delete" Grid.Row="9" Grid.Column="4" Grid.ColumnSpan="2" Clicked="btn_Delete_Clicked"></Button> <Button Text="返回" Grid.Row="9" Grid.Column="6" Grid.ColumnSpan="2" Clicked="btn_Back_Clicked"></Button> <Label x:Name="lbMessage" Grid.Row="10" Grid.Column="5" Grid.ColumnSpan="4" Text="" IsVisible="False"></Label> </Grid> <Grid x:Name="grdNumber" IsVisible="false"> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="*" /> <RowDefinition Height="*" /> </Grid.RowDefinitions> </Grid> </StackLayout> </ContentPage.Content> </ContentPage> GameEdit后台代码： using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using Xamarin.Forms; using Xamarin.Forms.Xaml; using ZL.Shudu.Services; namespace ZL.Shudu.Views { [QueryProperty(nameof(ItemId), nameof(ItemId))] [XamlCompilation(XamlCompilationOptions.Compile)] public partial class GameEdit : ContentPage { private bool IsSaved=false; private int currentId = 0; private static int[,] chess = new int[9, 9]; private Button[,] buttons = new Button[9, 9]; private Button[,] numbuttons = new Button[2, 5]; private Button currentButton; private Button currentNumBtn; public string ItemId { get { return currentId.ToString(); } set { currentId = int.Parse( value); if (currentId > 0) { var game = App.Database.GetGameAsync(currentId).Result; if(game != null) EditGame(game); } } } public GameEdit() { InitializeComponent(); SetLayout(); SetNumButtons(); } internal void EditGame(InputGameInfo game) { currentId = game.ID; for (var i = 0; i < 9; i++) for (var j = 0; j < 9; j++) { chess[i, j] = int.Parse(game.Sudoku.Substring(i * 9 + j, 1)); buttons[i, j].Text = chess[i, j] > 0 ? chess[i, j].ToString() : ""; buttons[i, j].IsEnabled = true; } } private void SetNumButtons() { var num = 1; for (var i = 0; i < 2; i++) { for (var j = 0; j < 5; j++) { var btn = new Button(); if (num == 10) { btn.Text = "清除"; btn.Clicked += Clear_Clicked; btn.FontSize = 15; } else { btn.Text = num.ToString(); btn.Clicked += Num_Clicked; btn.FontSize = 16; } btn.Padding = 0; grdNumber.Children.Add(btn, j, i); numbuttons[i, j] = btn; num++; } } } private void SetLayout() { for (var i = 0; i < 9; i++) { for (var j = 0; j < 9; j++) { int m = i / 3; int n = j / 3; var btn = new Button(); var c = new Color(0.9, 0.9, 0.9); if ((m + n) % 2 == 0) { c = new Color(0.7, 0.7, 0.7); } btn.BackgroundColor = c; btn.Padding = 0; btn.Margin = 0; btn.FontSize = 20; myGrid.Children.Add(btn, i, j); btn.Clicked += Btn_Clicked; buttons[i, j] = btn; } } } private async void btn_Save_Clicked(object sender, EventArgs e) { var str = ""; for (var i = 0; i < 9; i++) for (var j = 0; j < 9; j++) { if (string.IsNullOrEmpty(buttons[i, j].Text)) chess[i, j] = 0; else chess[i, j] = int.Parse(buttons[i, j].Text); str += chess[i, j].ToString(); } var newgame = new InputGameInfo { Sudoku = str, InputDate = DateTime.Now }; if (currentId > 0) { newgame.ID = currentId; await App.Database.UpdateGameAsync(newgame); } else { currentId = await App.Database.SaveGameAsync(newgame); } lbMessage.Text = "保存成功"; lbMessage.IsVisible = true; } private void btn_New_Clicked(object sender, EventArgs e) { lbMessage.Text = ""; currentId = 0; for (var i = 0; i < 9; i++) for (var j = 0; j < 9; j++) { buttons[i, j].Text = ""; buttons[i, j].IsEnabled = true; chess[i, j] = 0; } } private void Btn_Clicked(object sender, EventArgs e) { currentButton = sender as Button; rowResult.Height = 1; rowButton.Height = 1; grdNumber.IsVisible = true; } private async void btn_Delete_Clicked(object sender, EventArgs e) { if (currentId > 0) { await App.Database.DeleteGameAsync(new InputGameInfo { ID = currentId }); await Shell.Current.GoToAsync($"///{nameof(GameList)}"); } } private void Num_Clicked(object sender, EventArgs e) { currentNumBtn = sender as Button; int x = -1, y = -1; for (var i = 0; i < 9; i++) { for (var j = 0; j < 9; j++) { if (buttons[i, j] == currentButton) { x = i; y = j; break; } } } var num = int.Parse(currentNumBtn.Text); currentButton.Text = currentNumBtn.Text; myGrid.IsVisible = true; grdNumber.IsVisible = false; rowResult.Height = 40; rowButton.Height = 40; } private void Clear_Clicked(object sender, EventArgs e) { if (currentButton == null) return; currentButton.Text = ""; grdNumber.IsVisible = false; myGrid.IsVisible = true; rowResult.Height = 40; rowButton.Height = 40; } private async void btn_Back_Clicked(object sender, EventArgs e) { await Shell.Current.GoToAsync($"///{nameof(GameList)}"); } } } 编辑功能完成了，但还有一个问题，如果输入的游戏无法完成怎么办？这需要增加判断游戏是否可以完成的逻辑，如果无法完成，需要将UsedInGame属性设置为false，避免无效游戏。 在输入新的游戏时，我们需要确保输入的游戏合法并且能够完成，在输入过程中，可能需要随时检查合法性，在保存之前，需要确保游戏合法且可完成，然后才能保存。验证的方法就是使用计算机算法完成数独游戏，如果可以完成，就是合法的，否则就需要修改。相关的算法已经封装在程序包中，实现细节在这里不做讨论，将来会作为独立的文章详细介绍实现过程。可以使用Nuget程序包管理器进行安装：ZL.Sudoku.Lib。使用方法如下： var comp = new FindOneSolution(cinp); var res = comp.Comp(); var fchess = comp.Matrix; 上面算法中，cinp是输入的数独数组，使用Comp方法进行计算，如果res=2，说明计算完成，输出的结果使用Matrix属性获得，也是一个二维数组。如果res=1，说明无法完成，如果是其它值说明输入有错误。 安装完这个程序包后，我们可以改造GameEdit页面。首先增加一个按钮，用来在输入过程中验证是否合法和能够完成。 <Button Text="检查" x:Name="btn_Check" Grid.Row="9" Grid.Column="0" Grid.ColumnSpan="2" Clicked="btn_Check_Clicked"></Button> <Button Text="保存" Grid.Row="9" Grid.Column="2" Grid.ColumnSpan="2" Clicked="btn_Save_Clicked"></Button> <Button Text="删除" x:Name="btn_Delete" Grid.Row="9" Grid.Column="4" Grid.ColumnSpan="2" Clicked="btn_Delete_Clicked"></Button> <Button Text="返回" Grid.Row="9" Grid.Column="6" Grid.ColumnSpan="2" Clicked="btn_Back_Clicked"></Button> 后台代码： private void btn_Check_Clicked(object sender, EventArgs e) { if (btn_Check.Text == "检查") { var cinp = getChess(); lastinput = cinp; var comp = new FindOneSolution(cinp); var res = comp.Comp(); var fchess = comp.Matrix; for (var i = 0; i < 9; i++) { for (var j = 0; j < 9; j++) { var btn = buttons[i, j]; if (cinp[i, j] > 0) { btn.Text = cinp[i, j].ToString(); } else { btn.Text = fchess[i, j] > 0 ? fchess[i, j].ToString() : ""; } } } if (res == 0) lbMessage.Text = "不合法"; else if (res == 1) lbMessage.Text = "计算不出来"; else if (res == 2) lbMessage.Text = "计算完成"; else lbMessage.Text = "其它错误"; btn_Check.Text = "继续"; } else { lbMessage.Text = ""; btn_Check.Text = "检查"; for (var i = 0; i < 9; i++) { for (var j = 0; j < 9; j++) { var btn = buttons[i, j]; if (lastinput[i, j] > 0) { btn.Text = lastinput[i, j].ToString(); } else { btn.Text =""; } } } } } private int[,] getChess() { var res = new int[9, 9]; for (var i = 0; i < 9; i++) { for (var j = 0; j < 9; j++) { var btn = buttons[i, j]; if(string.IsNullOrEmpty(btn.Text)) res[i,j]= 0; else res[i, j]=int.Parse(btn.Text); } } return res; } 在保存前，也需要进行检查，如果不合法或者无法完成，就提示继续编辑，不能保存： private async void btn_Save_Clicked(object sender, EventArgs e) { if(btn_Check.Text=="继续") btn_Check_Clicked(null,null); var str = ""; var chess = getChess(); for (var i = 0; i < 9; i++) for (var j = 0; j < 9; j++) { str += chess[i, j].ToString(); } var comp = new FindOneSolution(chess); var res = comp.Comp(); if(res != 2) { lbMessage.Text = "不合法或者无法完成的游戏，请修改后保存"; return; } var newgame = new InputGameInfo { Sudoku = str, InputDate = DateTime.Now, UsedInGame = true }; if (currentId > 0) { newgame.ID = currentId; await App.Database.UpdateGameAsync(newgame); } else { currentId = await App.Database.SaveGameAsync(newgame); } lbMessage.Text = "保存成功"; } 到此，我们的数独游戏基本完成。下一步的工作是增加完成历史列表页面，让玩家查看已经完成的历史，并且能够复盘。 本文来自博客园，作者：寻找无名的特质，转载请注明原文链接：https://www.cnblogs.com/zhenl/p/15841119.html
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