ImageCrop

in namespace DotVVM.BusinessPack.Controls

Renders an ImageCrop control allowing to zoom, rotate and crop images.

Usage & Scenarios

A control which lets the user to make basic edits (like cropping, resizing or rotating) with a specified image.

Sample 1: Basic Usage

The ImageUrl property specifies the URL of the image that is being edited.

The Operations property must be bound to a property of type ImageOperations in the viewmodel. This object contains the following properties:

Resize represents the scale ratio of the image.
Rotate represents represents the rotation angle.
Crop represents a rectangular area (with Left, Top, Width and Height properties) the crop settings.
Round represents the radius of the rounded corners.

You can use the DefaultImageFactory class to load the image, apply the ImageOperations to it and save the result image.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}" />

<p>Left: {{value: ImageOperations.Crop.Left}}px</p>
<p>Top: {{value: ImageOperations.Crop.Top}}px</p>
<p>Width: {{value: ImageOperations.Crop.Width}}px</p>
<p>Height: {{value: ImageOperations.Crop.Height}}px</p>
<p>Rotate: {{value: ImageOperations.Rotate}}°</p>
<p>Resize: {{value: ImageOperations.Resize}}px</p>

<bp:Button Text="Save"
           Click="{command: Save()}" />
<br />
<br />

<p>Result: <a href="{value: Result}">{{value: Result}}</a></p>
<img src="{value: Result}" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.Utils;
using DotVVM.Framework.ViewModel;


namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample1
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "../images/imagecrop.webp";
        public string Result { get; set; }
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();

        public void Save()
        {
            Result = $"/App_Images/{SecureGuidGenerator.GenerateGuid()}.png";

            using (var factory = new DefaultImageFactory())
            {
                factory
                    .Load(GetPhysicalPath(ImagePath))
                    .Apply(ImageOperations)
                    .Save(GetPhysicalPath(Result));
            }
        }

        private string GetPhysicalPath(string url)
        {
            return Context.Configuration.ApplicationPhysicalPath + url.Substring(1).Replace("/", "\\");
        }
    }
}

Sample 2: Aspect Ratio

The ratio between the width and height of the cropped area can be set using the AspectRatio property. The value of the property is string and the control expects two numbers separated by a colon, e.g. 1:1, 4:3, 16:9 etc.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              AspectRatio="1:1" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample2
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "../images/imagecrop.webp";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Sample 3: Forced Crop Radius

To make the border radius fixed, the ForcedCropRadius property can be used. It expects a value between 0 and 50.

0 means no border radius. 50 means maximum border radius. The value is in percent, so the border radius of 50% can be used to make a circle.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              ForcedCropRadius="50" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;


namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample3
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "../images/imagecrop.webp";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Sample 4: Forced Crop Area

The crop area dimensions can be fixed using the ForcedCropWidth and ForcedCropHeight properties.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              ForcedCropWidth="150"
              ForcedCropHeight="150" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample4
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "../images/imagecrop.webp";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Sample 5: Changed Event

When the user changes any parameter of the image, the Changed event can be used to call a command in the viewmodel.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}"
              Changed="{command: Changed()}" />

<p>Change count: {{value: ChangeCount}}</p>

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample5
{
    public class ViewModel : DotvvmViewModelBase
    {
        public int ChangeCount { get; set; }
        public string ImagePath { get; set; } = "../images/imagecrop.webp";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();

        public void Changed()
        {
            ChangeCount++;
        }
    }
}

Sample 6: Predefined Operations

If you set the ImageOperations parameters from the viewmodel, you can specify default values for the control.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}" />

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample6
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "../images/imagecrop.webp";

        public ImageOperations ImageOperations { get; set; } = new ImageOperations {
            Crop = new CropRectangle {
                Left = 150,
                Top = 150,
                Width = 100,
                Height = 100
            },
            Resize = 400,
            Rotate = 45,
            Round = 50
        };
    }
}

Sample 7: Custom Icons

To customize the look of toolbar icons in the control, you can use the following inner elements:

SwitchToMovingIcon allows to customize the switch mode icon. The default value is Move.
SwitchToCroppingIcon allows to customize the switch mode icon. The default value is Crop.
ResetIcon allows to customize the reset icon. The default value is Reset.
RotateLeftIcon allows to customize the rotate left icon. The default value is RotateLeft.
RotateRightIcon allows to customize the rotate right icon. The default value is RotateRight.
ZoomInIcon allows to customize the zoom in icon. The default value is ZoomIn.
ZoomOutIcon allows to customize the zoom out icon. The default value is ZoomOut.

See the Icon documentation to find about using other icon packs.

page.dothtml
ViewModel.cs

<bp:ImageCrop ImageUrl="{value: ImagePath}"
              Operations="{value: ImageOperations}">
    <SwitchToMovingIcon>
        <bp:Icon Icon="Move"></bp:Icon>
    </SwitchToMovingIcon>
    <SwitchToCroppingIcon>
        <bp:Icon Icon="Crop"></bp:Icon>
    </SwitchToCroppingIcon>
    <ResetIcon>
        <bp:Icon Icon="Reset"></bp:Icon>
    </ResetIcon>
    <RotateLeftIcon>
        <bp:Icon Icon="RotateLeft"></bp:Icon>
    </RotateLeftIcon>
    <RotateRightIcon>
        <bp:Icon Icon="RotateRight"></bp:Icon>
    </RotateRightIcon>
    <ZoomInIcon>
        <bp:Icon Icon="ZoomIn"></bp:Icon>
    </ZoomInIcon>
    <ZoomOutIcon>
        <bp:Icon Icon="ZoomOut"></bp:Icon>
    </ZoomOutIcon>
</bp:ImageCrop>

using DotVVM.BusinessPack.Controls;
using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.businesspack.ImageCrop.sample7
{
    public class ViewModel : DotvvmViewModelBase
    {
        public string ImagePath { get; set; } = "../images/imagecrop.webp";
        public ImageOperations ImageOperations { get; set; } = new ImageOperations();
    }
}

Show all inherited properties

Properties

Name	Type	Description	Notes	Default Value
AspectRatio	String	Gets or sets the aspect ratio to force when cropping the image (eg. 1:1).	attribute inner element static value bindable default	null
ClientIDMode	ClientIDMode	Gets or sets the client ID generation algorithm.	attribute inner element static value bindable default	Static
DataContext	Object	Gets or sets a data context for the control and its children. All value and command bindings are evaluated in context of this value. The DataContext is null in client-side templates.	attribute inner element static value bindable default	null
ForcedCropHeight	Int32?	Gets or sets the forced height of the cropped image. If the ForcedCropWidth property is not set, it is computed automatically (see the AspectRatio).	attribute inner element static value bindable default	null
ForcedCropRadius	Int32?	Gets or sets the forced radius of the image corners. The value must be between 0 and 50 % (both inclusive). It is not set by default.	attribute inner element static value bindable default	null
ForcedCropWidth	Int32?	Gets or sets the forced width of the cropped image. If the ForcedCropHeight property is not set, it is computed automatically (see the AspectRatio).	attribute inner element static value bindable default	null
ID	String	Gets or sets the control client ID within its naming container.	attribute inner element static value bindable default	null
ImageUrl	String	Gets or sets the URL of an image to crop.	attribute inner element static value bindable default	null
IncludeInPage	Boolean	Gets or sets whether the control is included in the DOM of the page.	attribute inner element static value bindable default	True
InnerText	String	Gets or sets the inner text of the HTML element. Note that this property can only be used on HtmlGenericControl directly and when the control does not have any children.	attribute inner element static value bindable default	null
Operations	ImageOperations	Gets or sets the operations applied to the image being cropped.	attribute inner element static value bindable default	null
ResetIcon	IconBase	Gets or sets the icon displayed on the reset button.	attribute inner element static value bindable default	null
RotateLeftIcon	IconBase	Gets or sets the icon displayed on the rotate-left button.	attribute inner element static value bindable default	null
RotateRightIcon	IconBase	Gets or sets the icon displayed on the rotate-right button.	attribute inner element static value bindable default	null
SelectOnlyImage	Boolean	Gets or sets a value indicating selecting only image part.	attribute inner element static value bindable default	True
SwitchToCroppingIcon	IconBase	Gets or sets the icon displayed on the button switching from Cropping mode to Moving mode.	attribute inner element static value bindable default	null
SwitchToMovingIcon	IconBase	Gets or sets the icon displayed on the button switching from Cropping mode to Moving mode.	attribute inner element static value bindable default	null
Visible	Boolean	Gets or sets whether the control is visible. When set to false, `style="display: none"` will be added to this control.	attribute inner element static value bindable default	True
ZoomInIcon	IconBase	Gets or sets the icon displayed on the zoom-in button.	attribute inner element static value bindable default	null
ZoomOutIcon	IconBase	Gets or sets the icon displayed on the zoom-out button.	attribute inner element static value bindable default	null

Events

	Name	Type	Description
	Changed	Command	Gets or sets the command triggered when the image attributes are changed.

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