以编程方式在WPF中使用*设置网格列的宽度

Question

我想以编程方式配置wpf网格.

我希望能够设置一个包含2列的网格,第一列占用可用空间的20%,第二列占80%.在xaml中我会使用*运算符,但我无法解决如何以编程方式执行此操作.

在Xaml我会这样做:

<Grid>
  <Grid.ColumnDefinitions>
    <ColumnDefinition width="20*" />
    <ColumnDefinition width="80*" />
</Grid>

在我想要的代码中:

Grid grid = new Grid();
grid.ColumnDefinitions.Add( new ColumnDefinition(20*) );
grid.ColumnDefinitions.Add( new ColumnDefinition(80*) );

请有人建议.

Answer 1

Grid grid = new Grid();
ColumnDefinition c1 = new ColumnDefinition();
c1.Width = new GridLength(20, GridUnitType.Star);
ColumnDefinition c2 = new ColumnDefinition();
c2.Width = new GridLength(80, GridUnitType.Star);
grid.ColumnDefinitions.Add(c1);
grid.ColumnDefinitions.Add(c2);

Answer 2

假设您在页面中有一些按钮(水平对齐),需要根据某些状态隐藏/显示某些按钮.

<Grid HorizontalAlignment="Center" Grid.Column="1" Width="340" VerticalAlignment="Center" Background="Transparent">
        <Grid.ColumnDefinitions>
                <ColumnDefinition Width="2*" x:Name="colOne"></ColumnDefinition>
                <ColumnDefinition Width="0" x:Name="colTwo"></ColumnDefinition>
                <ColumnDefinition Width="0" x:Name="colThree"></ColumnDefinition>
                <ColumnDefinition Width="0" x:Name="colFour"></ColumnDefinition>
        </Grid.ColumnDefinitions>

        <Button x:Name="btnOne"  Grid.Column="0" Height="50" Width="50" Content="One" Cursor="Hand" />
        <Button x:Name="btnTwo"  Grid.Column="1" Height="50" Width="50" Content="Two" Cursor="Hand" />
        <Button x:Name="btnThree"  Grid.Column="2" Height="50" Width="50" Content="Thre" Cursor="Hand" />
        <Button x:Name="btnFour"  Grid.Column="3" Height="50" Width="50" Content="Four" Cursor="Hand" />
</Grid>

这里btnOne在执行时会在页面中显示.btnOne也将在中心对齐.现在,如果我们想要显示Three和Four,并且当单击One时隐藏One,我们可以使用此代码:

private void btnOne_Click(object sender, RoutedEventArgs e)
{
    SetGridColWidth(colOne, false);
    SetGridColWidth(colThree, true);
    SetGridColWidth(colFour, true);
}

private void SetGridColWidth(ColumnDefinition column, bool show)
{
    if (show)
        column.Width = new GridLength(2, GridUnitType.Star);
    else
        column.Width = new GridLength(0);
}

您可以在运行时切换任何按钮的可见性.

希望这有助于某人!

Answer 3

MVVM方法

查看 (XAML)

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="{Binding FirstColumn}"/>
        <ColumnDefinition Width="{Binding SecondColumn}"/>
    </Grid.ColumnDefinitions>
</Grid>

视图模型 (C#)

public class MyViewModel : BindableBase
{
    private GridLength _firstColumn;
    private GridLength _secondColumn;

    public MyViewModel()
    {
        _firstColumn = new GridLength(75, GridUnitType.Star);
        _secondColumn = new GridLength(25, GridUnitType.Star);
    }

    public GridLength FirstColumn
    {
        get { return _firstColumn; }
        set { SetProperty(ref _firstColumn, value); }
    }

    public GridLength SecondColumn
    {
        get { return _secondColumn; }
        set { SetProperty(ref _secondColumn, value); }
    }

    private void NotifyToggleFullScreen(bool isToggleExpansion)
    {
        if (isToggleExpansion)
        {
            FirstColumn = new GridLength(0, GridUnitType.Auto);
            SecondColumn = new GridLength(100, GridUnitType.Star);
        }
        else
        {
            FirstColumn = new GridLength(75, GridUnitType.Star);
            SecondColumn = new GridLength(25, GridUnitType.Star);
        }
    }
}