WPF Error - Where to look for source / solution

Question

I am very new to WPF. I create an app that gets data from a web service. Data consists of strings, dates, numbers and images.

The app runs (no crashing) however and I thought all is fine. My data is also displayed just fine. However, I see in the Output window following:

System.Windows.Data Error: 23 : Cannot convert '<null>' from type '<null>' to type 'System.Windows.Media.ImageSource' for 'en-US' culture with default conversions; consider using Converter property of Binding. NotSupportedException:'System.NotSupportedException: ImageSourceConverter cannot convert from (null).
   at System.ComponentModel.TypeConverter.GetConvertFromException(Object value)
   at System.Windows.Media.ImageSourceConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
   at MS.Internal.Data.DefaultValueConverter.ConvertHelper(Object o, Type destinationType, DependencyObject targetElement, CultureInfo culture, Boolean isForward)'

What could cause this error? Where to start looking to fix this issue?

Sorry, I know the question is bit vague and I have not provided code because dont know what to provide, it would be to much to provide it all.

Did you debug and check at which point the error and coming? — Mangesh, Dec 23 '15 at 05:13
Check the code where you are trying to show Image. ImageSource should be non-null. — AnjumSKhan, Dec 23 '15 at 05:15
Can you share the part of the XAML which has the tag with it's *Source* property being bound? — bit, Dec 23 '15 at 05:36
just have a look at http://stackoverflow.com/questions/4997365/solution-to-binding-errors-thrown-by-setting-image-source-to-a-binding-to-null — Justin CI, Dec 23 '15 at 06:16

Avner Shahar-Kashtan · Accepted Answer · 2015-12-23T07:44:23.133

Follow the data in the first line of the error message:

Cannot convert <null> from type <null> to type 'System.Windows.Media.ImageSource'

This means that in your XAML somewhere you're binding a property that expects to receive an ImageSource - usually, this means an <Image Source="{Binding ...}"/>. However, instead of an instance of an ImageSource, you're giving it null.

You might not notice it in the visual layout because it just doesn't appear, but you should go over your image bindings and look for it.

WPF Error - Where to look for source / solution

1 Answers1