CODEWITHSUNDEEP
wpfxamlwindows-phone-7windows-phone-8
user2715606
user2715606

Reputation: 287

How to set a default source for an Image if binding source is null?

I'm using binding for source of an Image control.

<Image Source="{Binding ImageUri}"/>

But this ImageUri can be null, therefor I want to use a default image, a place holder, for that, which can be in /Assets/PlaceHolder.png for example.

How can I set a default image? thanks. (It's a WP8 app, but should not be different of WPF)

Upvotes: 23

Views: 24098

Answers (7)

Hossein Narimani Rad
Hossein Narimani Rad

Reputation: 32481

You may try this:

<Image>
    <Image.Source>
        <Binding Path="ImageUri">
            <Binding.TargetNullValue>
                <BitmapImage UriSource="/ProjName;component/Assets/PlaceHolder.png" />                    
            </Binding.TargetNullValue>
        </Binding>
    </Image.Source>
</Image>

Upvotes: 2

Muhammad Ammar
Muhammad Ammar

Reputation: 11

use TargetNullValue attribute. It is very helpful if I don't want to display any image.

Upvotes: 1

Shikhar
Shikhar

Reputation: 1431

You can actually go the other way around which is a better experience in my opinion by simply using two Image controls in a Grid layout, one with the local placeholder source and one with the remote Binding. The local image is already there when you your remote binding is null. However if the binding is not null, it automatically covers the local placeholder image once it gets rendered.

<Grid>
    <Image Source="Assets/Placeholder.png"/>
    <Image Source="{Binding ImageUri}"/>
</Grid>

Upvotes: 4

ZombieSheep
ZombieSheep

Reputation: 29953

You can set the ImageFailed event on your image, 

<Image Source="{Binding ImageUri}" ImageFailed="Image_ImageFailed"/>

and use the following C# to load a specific image in its place.

private void Image_ImageFailed(object sender, ExceptionRoutedEventArgs e)
{
    ((Image)sender).Source = new BitmapImage(new Uri("/Assets/MyDefaultImage.png", UriKind.Relative));
}

Upvotes: 3

SeyedPooya Soofbaf
SeyedPooya Soofbaf

Reputation: 2649

You can use ImageFailed event and ChangePropertyAction.

This Code Snippet worked for me:

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"

<Image x:Name="GeologyMapsLegend" Stretch="Fill" Height="150">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="ImageFailed">
            <ei:ChangePropertyAction PropertyName="Source" TargetName="GeologyMapsLegend">
                <ei:ChangePropertyAction.Value>
                    <ImageSource>
                        /LanSysWebGIS;component/Pictures/Icon/NoImageAvailable.jpg
                    </ImageSource>
                </ei:ChangePropertyAction.Value>
            </ei:ChangePropertyAction>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</Image>

Upvotes: 1

Nitesh
Nitesh

Reputation: 7409

You can achieve it by setting TargetNullValue

<Image>
    <Image.Source>
        <Binding Path="ImageUri" >
            <Binding.TargetNullValue>
                <ImageSource>/Assets/PlaceHolder.png</ImageSource>
            </Binding.TargetNullValue>
        </Binding>
    </Image.Source>
</Image>

Upvotes: 35

AsitK
AsitK

Reputation: 673

You should try to play with FallBackValue here. These two links should provide more help

WPF Binding - Default value for empty string

MSDN

Upvotes: -2

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