How do I set a grid column/row size without defining each line?

Question

I have a grid. I have to define each column and row manually, like this:

<Window x:Class="GridBuild"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="GridBuild" Height="300" Width="300">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>        
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>        
</Grid>

I want to define the number of rows and columns with a single line, something like this:

<Window x:Class="GridBuild"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="GridBuild" Height="300" Width="300">
    <Grid>
        <Grid.NumberOfRows="2"/>
        <Grid.NumberOfColumns/>
    </Grid>
</Window>

Answer 1

What you describe is called UniformGrid. It has Columns and Rows properties by which you can set the number of rows or columns that you want.

If you don't set these properties, the UniformGrid will try to layout the children as close to a square as it can. In this situation, it prefers to increase the number of columns before increasing the number of rows.

It's an obscure panel, but it's extremely powerful when used correctly.

Answer 2

I propose deriving from Grid and adding these properties to it like following:

public class GridEx : Grid
{
    public int NumberOfRows
    {
        get { return RowDefinitions.Count; }
        set
        {
            RowDefinitions.Clear();
            for (int i = 0; i < value; i++)
                RowDefinitions.Add(new RowDefinition());
        }
    }

    public int NumberOfColumns
    {
        get { return ColumnDefinitions.Count; }
        set
        {
            ColumnDefinitions.Clear();
            for (int i = 0; i < value; i++)
                ColumnDefinitions.Add(new ColumnDefinition());
        }
    }
}

Now it can be used as following:

<local:GridEx NumberOfRows="3" NumberOfColumns="2">
    <TextBox>some text</TextBox>
    <TextBox Grid.Row="1">some text</TextBox>
    <TextBox Grid.Row="2">some text</TextBox>

    <TextBox Grid.Column="1">some text</TextBox>
    <TextBox Grid.Row="1" Grid.Column="1">some text</TextBox>
    <TextBox Grid.Row="2" Grid.Column="1">some text</TextBox>
</local:GridEx>

Works in designer as well by the way :)

The challenge here is to set different Width, Height etc. for different rows and columns. I have a nice thought how to do this. Also it is possible to automate assigning Grid.Row and Grid.Column. Think of it :)

Answer 3

The above answer by EvAlex will work, but only if you don't want to set the number of column/rows using data binding.

public class GridEx : Grid
{
    public int NumberOfRows
    {
        get { return RowDefinitions.Count; }
        set
        {
            RowDefinitions.Clear();
            for (int i = 0; i < value; i++)
                RowDefinitions.Add(new RowDefinition());
        }
    }

    public int NumberOfColumns
    {
        get { return ColumnDefinitions.Count; }
        set
        {
            ColumnDefinitions.Clear();
            for (int i = 0; i < value; i++)
                ColumnDefinitions.Add(new ColumnDefinition());
        }
    }
}

If you do want to set these via data binding (like I do), then with the above solution the compiler will complain because it needs DependencyProperties for that. A DependencyProperty can be implemented (using C# 6's nameof operator) as follows (a quick way to insert it is using the snippet propdp):

public int Columns
{
    get { return (int) GetValue(ColumnsDependencyProperty); }
    set { SetValue(ColumnsDependencyProperty, value); }
}
public static readonly DependencyProperty ColumnsDependencyProperty =
    DependencyProperty.Register(nameof(Columns), typeof(int), typeof(GridEx), new PropertyMetadata(0));

But this way you can't execute the necessary logic to add the necessary number of RowDefinitions. To solve this, define a DependencyPropertyDescriptor for each DependencyProperty and add an AddValueChanged call with the necessary logic to it in your custom class's constructor. The result per propery is then (using C# 6's null-conditional operator ?.):

    public int Columns
    {
        get { return (int) GetValue(ColumnsDependencyProperty); }
        set { SetValue(ColumnsDependencyProperty, value); }
    }
    public static readonly DependencyProperty ColumnsDependencyProperty =
        DependencyProperty.Register(nameof(Columns), typeof(int), typeof(GridEx), new PropertyMetadata(0));

    DependencyPropertyDescriptor ColumnsPropertyDescriptor = DependencyPropertyDescriptor.FromProperty(ColumnsDependencyProperty, typeof(GridEx));

    public GridEx()
    {
        ColumnsPropertyDescriptor?.AddValueChanged(this, delegate
        {
            ColumnDefinitions.Clear();
            for (int i = 0; i < Columns; i++)
                ColumnDefinitions.Add(new ColumnDefinition());
        });
    }