Editing and using the Xamarin.Forms source code

Question

I was wondering if it was possible to edit the Xamarin.Forms source code and then use the edited one like you normally would in your xamarin.forms project.

Basically

Answer 1

I don't recommend you to edit the source code. But we can also create our own MasterDetailPage's Renderer. It may be a little difficult, let's do this step by step.

Firstly, define a BindableProperty in our own MasterDetailPage class like:

public readonly static BindableProperty WidthRatioProperty =
            BindableProperty.Create("WidthRatio",
            typeof(float),
            typeof(MyMasterDetailPage),
            (float)0.2);

public float WidthRatio
{
    get
    {
        return (float)GetValue(WidthRatioProperty);
    }
    set
    {
        SetValue(WidthRatioProperty, value);
    }
}

Secondly, try to create our own renderer instead of using the form's default renderer. I post my source code here about my own renderer. In this class I use widthRatio changing the master's width. This property can be set in:

void HandlePropertyChanged(object sender, PropertyChangedEventArgs e)
{
    ...
    else if(e.PropertyName == "WidthRatio")
    {
        widthRatio = ((MyMasterDetailPage)Element).WidthRatio;
    }
}

At last, create the custom renderer inheriting the renderer above like:

[assembly: ExportRenderer(typeof(MyMasterDetailPage), typeof(MyMasterDetailPageRenderer))]
namespace MasterDetailDemo.iOS
{
    public class MyMasterDetailPageRenderer : MyPhoneMasterDetailRenderer
    {
    }
}

You can set the property WidthRatio's value in forms's MasterDetailPage to change the width now. You can run my demo to test it.

Besides if you want to do this on Android, please refer to this thread.