作为一个样式如何使其在WPF使用的例子,,让我们看一下TTT简单的实现,如示例5-1。
示例5-1
<!-- Window1.xaml --> < Window x:Class ="TicTacToe.Window1" xmlns ="http://schemas.microsoft.com/winfx/avalon/2005" xmlns:x ="http://schemas.microsoft.com/winfx/xaml/2005" Text ="TicTacToe" > <!-- the black background lets the tic-tac-toe --> <!-- crosshatch come through on the margins --> < Grid Background ="Black" > < Grid.RowDefinitions > < RowDefinition /> < RowDefinition /> < RowDefinition /> </ Grid.RowDefinitions > < Grid.ColumnDefinitions > < ColumnDefinition /> < ColumnDefinition /> < ColumnDefinition /> </ Grid.ColumnDefinitions > < Button Margin ="0,0,2,2" Grid.Row ="0" Grid.Column ="0" x:Name ="cell00" /> < Button Margin ="2,0,2,2" Grid.Row ="0" Grid.Column ="1" x:Name ="cell01" /> < Button Margin ="2,0,0,2" Grid.Row ="0" Grid.Column ="2" x:Name ="cell02" /> < Button Margin ="0,2,2,2" Grid.Row ="1" Grid.Column ="0" x:Name ="cell10" /> < Button Margin ="2,2,2,2" Grid.Row ="1" Grid.Column ="1" x:Name ="cell11" /> < Button Margin ="2,2,0,2" Grid.Row ="1" Grid.Column ="2" x:Name ="cell12" /> < Button Margin ="0,2,2,0" Grid.Row ="2" Grid.Column ="0" x:Name ="cell20" /> < Button Margin ="2,2,2,0" Grid.Row ="2" Grid.Column ="1" x:Name ="cell21" /> < Button Margin ="2,2,0,0" Grid.Row ="2" Grid.Column ="2" x:Name ="cell22" /> </ Grid > </ Window >
这个grid 的外观上排列了一组9 个按钮在一个3X3 栅格的TTT 单元中,在按钮上使用了页面空白为了TTT 的交叉线阴影。对游戏逻辑的一个简单的实现,在xaml 后台代码中,如示例5-2 所示。 示例5-2
// Window1.xaml.cs namespace TicTacToe { public partial class Window1 : Window { // Track the current player (X or O) string currentPlayer; // Track the list of cells for finding a winner etc. Button[] cells; public Window1( ) { InitializeComponent( ); // Cache the list of buttons and handle their clicks this.cells = new Button[] { this.cell00, this.cell01, }; foreach( Button cell in this.cells ) { cell.Click += cell_Click; } // Initialize a new game NewGame( ); } // Wrapper around the current player for future expansion, // e.g. updating status text with the current player string CurrentPlayer { get { return this.currentPlayer; } set { this.currentPlayer = value; } } // Use the buttons to track game state void NewGame( ) { foreach( Button cell in this.cells ) { cell.Content = null; } CurrentPlayer = "X"; } void cell_Click(object sender, RoutedEventArgs e) { Button button = (Button)sender; // Don't let multiple clicks change the player for a cell if( button.Content != null ) { return; } // Set button content button.Content = CurrentPlayer; // Check for winner or a tie if( HasWon(this.currentPlayer) ) { MessageBox.Show("Winner!", "Game Over"); NewGame( ); return; } else if( TieGame( ) ) { MessageBox.Show("No Winner!", "Game Over"); NewGame( ); return; } // Switch player if( CurrentPlayer == "X" ) { CurrentPlayer = "O"; } else { CurrentPlayer = "X"; } } // Use this.cells to find a winner or a tie bool HasWon(string player) { } bool TieGame( ) { } }}
我们的简单TTT 逻辑使用字符串代表玩家,使用按钮来跟踪游戏状态。当点击任意一个按钮时,我们将内容设置为字符串,用来象征当前玩家以及转换玩家。当游戏结束的时候,每一个按钮上的内容都会被清除。游戏中的截图如图5-1 。 图5-1
注意到图5-1中,grid的背景来自页面的空白。这些空白差不多使grid看上去像一个可绘制的TTT木板(虽然我们将来会做的更好)。然而,如果我们真的指望模仿一个手绘的游戏,我们已经对按钮上的字体大小做了设置,但并没匹配到线条的厚度。
一种修复这个问题的方法是为每一个按钮对象设置字体和宽度,如示例5-3。
示例5-3
< Button FontSize ="32" FontWeight ="Bold" x:Name ="cell00" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell01" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell02" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell10" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell11" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell12" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell20" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell21" /> < Button FontSize ="32" FontWeight ="Bold" x:Name ="cell22" />
依照我的视觉敏感性,今天,虽然这样做使得
X 的和O 的外观更好,一旦我以后想改动它,我就要负责在9 个独立的地方改变这些属性,这是重复性的努力——违反了我的编码敏感性。我宁愿重制我的决定——为了以后的维护,将我的TTT 单元的外观放在一个共同的地方。这是样式派得上用场的地方。