如何避免RowDefinition重复？

Question

I have 15-20 rows, some of them are different but most of them are similar:

        <RowDefinition Height="Auto" />

And I want to avoid code duplication, because it's about 10 rows, which goes one by one. How can it be done?

It can be done in code without XAML, but I think it is wrong way to solve this problem.

Answer 1

I don't think it's possible to somehow shorthand declaration of grid rows, especially when not all of them have the Height property set to "Auto". You could try using an attached dependency property as demonstrated here .

Please note that this example specifies the number of grid rows and you can see it sets the Height property of each row programmatically. You may have to decide what Height to assign to each row in a more complex way. Although this solution might prove to be more aesthetic in XAML, it may be more complicated to implement and you might have a hard time assigning the proper Height for each row. Personally it seems easier to just declare each row as Visual Studio will allow collapsing the tag and a nice, clear aspect.

I hope this helps!

Answer 2

I solved this before by writing a class that offers an attached property to automatically define rows and columns based on a simple comma separated list. What you essentially need to do is create a attached property (I called it AutoRows and define a method for the property-changed metadata. That method parses the value and simply creates new RowDefinition elements.

I used a simple syntax where each value within a comma-separated list equals to a single row. So 20,20,20 would create 3 rows with the height 20 . To allow rows with the height auto and also save room, I added a new format to define multiple auto rows in a block. For example 20,~5,20 defines a row with height 20 , then 5 auto-rows and finally another row with height 20 .

My change handler basically does this:

public static void AutoRowsChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
    RowDefinitionCollection rows = ((Grid)obj).RowDefinitions;
    rows.Clear();

    foreach (string segment in ((string)e.NewValue).Split(','))
    {
        if (segment.StartsWith("~"))
        {
            int count;
            if (!int.TryParse(segment.Substring(1), out count))
                count = 1;

            for (int i = 0; i < count; i++)
                rows.Add(new RowDefinition() { Height = GridLength.Auto });
        }
        else
        {
            GridLengthConverter converter = new GridLengthConverter();
            rows.Add(new RowDefinition() { Height = (GridLength)converter.ConvertFromString(segment) });
        }
    }
}

I left out a few lines that ensured it is parsed correctly and that nothing fails. As you can see, I use the GridLengthConverter to make each non-auto value accept any value that the normal RowDefinition supports. So you can easily join all the row heights by a comma and use it as the value for your attached property.