Question

我需要在程序中更改columnDefinition的width和rowDefinition的Height，所以绑定对我来说似乎是一个不错的选择。我尝试将ColumnDefinition的width和RowDefinition的Grid高度绑定到一个Object“StrategyObject”属性。对于演示，我们尝试更改以下网格的列和行的大小（请参阅屏幕截图）。

我将策略模式与抽象类“BaseStrategyObject”：

一起使用

public abstract class BaseStrategyObject
{
    protected GridLength gridFirstRowHeight;
    public GridLength GridFirstRowHeight
    {
        get { return this.gridFirstRowHeight; }
    }

    protected GridLength gridSecondRowHeight;
    public GridLength GridSecondRowHeight
    {
        get { return this.gridSecondRowHeight; }
    }

    protected GridLength gridFirstColumnWidth;
    public GridLength GridFirstColumnWidth
    {
        get { return this.gridFirstColumnWidth; }
    }

    protected GridLength gridSecondColumnWidth;
    public GridLength GridSecondColumnWidth
    {
        get { return this.gridSecondColumnWidth; }
    }
}

以下是三个具体的startegy类：

public class Strategy1Object : BaseStrategyObject
{
    public Strategy1Object()
    {
        this.gridFirstColumnWidth = new GridLength(1, GridUnitType.Star);
        this.gridFirstRowHeight = new GridLength(1, GridUnitType.Star);
        this.gridSecondColumnWidth = new GridLength(1, GridUnitType.Star);
        this.gridSecondRowHeight = new GridLength(1, GridUnitType.Star);
    }
}

public class Strategy2Object : BaseStrategyObject
{
    public Strategy2Object()
    {
        this.gridFirstColumnWidth = new GridLength(80, GridUnitType.Star);
        this.gridFirstRowHeight = new GridLength(1, GridUnitType.Star);
        this.gridSecondColumnWidth = new GridLength(20, GridUnitType.Star);
        this.gridSecondRowHeight = new GridLength(1, GridUnitType.Star);
    }
}

public class Strategy3Object : BaseStrategyObject
{
    public Strategy3Object()
    {
        this.gridFirstColumnWidth = new GridLength(80.0, GridUnitType.Pixel);
        this.gridFirstRowHeight = new GridLength(200.0, GridUnitType.Pixel);
        this.gridSecondColumnWidth = new GridLength(200.0, GridUnitType.Pixel);
        this.gridSecondRowHeight = new GridLength(80.0, GridUnitType.Pixel);
    }
}

窗口的Xaml代码：

<Window x:Class="GridAsteriskBindingtest.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525" DataContext="{Binding RelativeSource={RelativeSource Self}}">
<DockPanel>
    <StackPanel DockPanel.Dock="Bottom" HorizontalAlignment="Center" Orientation="Horizontal">
        <Button Click="Strategy1_Click">Strategy1</Button>
        <Button Click="Strategy2_Click">Strategy2</Button>
        <Button Click="Strategy3_Click">Strategy3</Button>
    </StackPanel>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="{Binding Mode=OneWay, Path=StrategyObject.GridFirstRowHeight}"/>
            <RowDefinition Height="{Binding Mode=OneWay, Path=StrategyObject.GridSecondRowHeight}"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="{Binding Mode=OneWay, Path=StrategyObject.GridFirstColumnWidth}"/>
            <ColumnDefinition Width="{Binding Mode=OneWay, Path=StrategyObject.GridFirstColumnWidth}"/>
        </Grid.ColumnDefinitions>
        <Rectangle Grid.Row="0" Grid.Column="0"
            Fill="Red"/>
        <Rectangle Grid.Row="0" Grid.Column="1"
            Fill="Yellow"/>
        <Rectangle Grid.Row="1" Grid.Column="0"
            Fill="Blue"/>
        <Rectangle Grid.Row="1" Grid.Column="1"
            Fill="Green"/>
    </Grid>
</DockPanel>

和窗口的.cs：

public partial class MainWindow : Window , INotifyPropertyChanged
{
    private BaseStrategyObject strategyObject;
    public BaseStrategyObject StrategyObject
    {
        get { return this.strategyObject; }
        set
        {
            this.strategyObject = value;
            OnStrategyObjectChanged();
        }
    }

    public MainWindow()
    {
        this.strategyObject = new Strategy1Object();

        InitializeComponent();
    }

    private void Strategy1_Click(object sender, RoutedEventArgs e)
    {
        this.StrategyObject = new Strategy1Object();
    }

    private void Strategy2_Click(object sender, RoutedEventArgs e)
    {
        this.StrategyObject = new Strategy2Object();
    }

    private void Strategy3_Click(object sender, RoutedEventArgs e)
    {
        this.StrategyObject = new Strategy3Object();
    }

    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    private void OnStrategyObjectChanged()
    {
        if(this.PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs("StrategyObject"));
    }

    #endregion
}

单击按钮将新对象应用于“StrategyObject”属性。

当我们启动该程序时，Strategy3（具有特定大小GridUnit.Pixel）工作正常，但它不适用于其他两个策略（策略1和2（未考虑星数： - （））。

以下是ScreenShots（策略1和2给出相同的结果）。

Strategy 1 & 2 Screenshot

Strategy 3 Screenshot

我做错了吗？谢谢！

ColumnDefinition的绑定宽度不适用于GridUnitType.Star

0 个答案: