You can move a modal window past the bottom and out of view. At that point the only way to get back to it is to zoom out on the browser. Similarly, if you drag a window to the top, you can move it so high that the title bar is out of view. You can still see the bottom part of the window but even if you zoom out you can't get back to the title bar so the only thing you can do is to either escape out of the window or hope you have Ok/Cancel still visible.

---

ADMIN EDIT

Until a feature is implemented that can do this automatically (whether behind a flag like in our WebForms suite or not), you can handle the window events to check the Top and Left values and compare them with the viewport and the window size.

Here is a basic example:

<TelerikWindow Left="@TheLeft" Top="@TheTop" Draggable="true"
               LeftChanged="@LeftChangedHandler" TopChanged="@TopChangedHandler"
               Visible="true" Width="400px" Height="300px">
    <WindowTitle>Drag me!</WindowTitle>
    <WindowContent>When using Left and Top, make sure to update them in the view-model.</WindowContent>
    <WindowActions>
        <WindowAction Name="Minimize"></WindowAction>
        <WindowAction Name="Maximize"></WindowAction>
    </WindowActions>
</TelerikWindow>

@code{
    string TheLeft { get; set; } = "50px";
    string TheTop { get; set; } = "50px";

    async Task LeftChangedHandler(string currLeft)
    {
        float leftValue = float.Parse(currLeft.Replace("px", ""));
        Console.WriteLine("left " + leftValue);
        //left boundary
        if (leftValue < 0)
        {
            currLeft = "0px";
        }
        //right boundary - replace hardcoded values with current values from the viewport size
        //and take into account the dimensions of your window. This sample hardcodes values for brevity and clarity
        //you may find useful packages like this to get the viewport size https://www.nuget.org/packages/BlazorPro.BlazorSize/
        if (leftValue > 1000)
        {
            currLeft = "1000px";
        }


        TheLeft = currLeft;

        await DelayedRender();
    }

    async Task TopChangedHandler(string currTop)
    {
        float topValue = float.Parse(currTop.Replace("px", ""));
        Console.WriteLine("top: " + topValue);

        //top boundary
        if (topValue < 0)
        {
            currTop = "0px";
        }
        //bottom boundary - replace hardcoded values with current values from the viewport size
        //and take into account the dimensions of your window
        if (topValue > 600)
        {
            currTop = "600px";
        }

        TheTop = currTop;

        await DelayedRender();
    }

    async Task DelayedRender()
    {
        await Task.Run(async () =>
        {
            await Task.Delay(30);
            await InvokeAsync(StateHasChanged);
        });
    }
}

---

It would be nice to be able to configure a show/hide animation for windows.

ADMIN EDIT: This might include a form of a Shown event so that you could know when the content is rendered and available to, for example, focus a button or input. For more details see here

Scenario is a page containing a grid component and a child component based on the TelerikWindow for viewing/adding/editing.  Record selection in grid makes child component visible.  Full-record editing may exceed available display space.  I have already broken down the model form into smaller pieces using tabstrips but some of the remaining pieces cannot be logically broken up much further.

I would like for optional (or automatic) creation of vertical and horizontal scroll bars on the window when the content exceeds the size of the editing window.

Currently, oversize content is off-screen and not reachable.

I would like to have an event that fires when the user closes the Window and to be able to cancel the event. I would like to have an identifier if the user pressed the "Esc" key or the Close button rendered in the Browser.

---

ADMIN EDIT

---

At the time of writing, only using the VisibleChanged event can let you prevent the Window from closing. As a workaround, you can cancel this event and use a custom close command that will not trigger it to, effectively, disable closing with Esc: https://blazorrepl.telerik.com/GcaqOxkT13mCiQ4q33.

I would like to be to allow the user to resize the Blazor Telerik Window component to their individual liking. For example, like a resizable textbox but for a window/modal. I would assume this would function the same way as I would resize a window in Windows OS by dragging the corner or sides of an open window.

Currently, when the window is minimized the content is lost. The content area is detached from the DOM and re-initialized when it is shown again.

<AdminEdit>

Workaround:

You can workaround that issue by creating custom minimize and maximize actions for the window, where you hide the content area with CSS.

Code snippet:

<TelerikWindow Class="@( isMinimized ? "minimize-window" : "maximize-window" )"
               Width="500px"
               Height="@Height"
               Top="40%"
               Left="45%"
               Visible="true">
    <WindowTitle>
        <strong>Status</strong>
    </WindowTitle>
    <WindowActions>
        <WindowAction Name="MyCustomMinimize" OnClick="@CustomMinimize" Icon="@IconName.WindowMinimize"></WindowAction>
        @if (isMinimized)
        {
            <WindowAction Name="MyCustomMaximize" OnClick="@CustomMaximize" Icon="@IconName.Window"></WindowAction>
        }
        <WindowAction Name="Close"></WindowAction>
    </WindowActions>
    <WindowContent>
        <form class="k-form">
            <fieldset class="k-form-fieldset">
                <legend class="k-form-legend">User Details</legend>

                <label class="k-form-field">
                    <span>First Name</span>
                    <input class="k-textbox" placeholder="Your Name" />
                </label>
                <label class="k-form-field">
                    <span>Last Name</span>
                    <input class="k-textbox" placeholder="Your Last Name" />
                </label>
            </fieldset>
        </form>
    </WindowContent>
</TelerikWindow>

@code {
    public bool isMinimized { get; set; }

    public string Height { get; set; } = "350px";

    private void CustomMinimize()
    {
        isMinimized = true;
        Height = "auto";
    }

    private void CustomMaximize()
    {
        isMinimized = false;
        Height = "350px";
    }

}

<style>
    .minimize-window .k-content {
        display: none;
        padding: 0px !important;
    }

    .maximize-window .k-content {
        display: block;
        padding: 16px 16px;
    }
</style>

</AdminEdit>

The Window-Component provides parameters for setting width and height.

In addition to that, it would be great if parameters for MaxWidth, MaxHeight + MinWidth, MinHeight would be provided.

I'm especially missing a MaxHeight parameter for creating popups that grow with the content (only known at runtime) but do not become larger than the screen. 
To make sure that the whole content is reachable by the users I'm setting the Height to 95vh but this leaves white space if there is not enough content to fill the screen.

Regards,

René

I am running into an issue with what I believe is the default behaviour of the TelerikWindow, namely capturing @onkeydown - events and closing the window when the user presses escape.

Is there any way to disable this default behaviour of the dialog / overwrite its onkeydown event handler?

---
ADMIN EDIT

Include the ability to :

• Disable keyboard shortcuts altogether
• Use custom keyboard shortcuts
• Use a combination of several keys (e.g. Shift + ESC)
• Define several keyboard shortcuts at the same time for the same action

If you have any preferences how to expose this functionality please leave a comment. Any feedback on how to handle this on a Mac for the Ctrl and CMD keys is welcome (e.g. should the shortcut for the Ctrl key handle the CMD key for the Mac automatically).

In the meantime you could use the following snippet as a workaround to disable the Esc key:

@result

<TelerikButton OnClick="@ToggleWindow">Toggle the Window</TelerikButton>

<TelerikWindow Visible="@isVisible" VisibleChanged="@VisibleChangedHandler">
    <WindowTitle>
        <strong>The Title</strong>
    </WindowTitle>
    <WindowContent>
        This is my window <strong>popup</strong> content.
    </WindowContent>
    <WindowActions>
        <WindowAction Name="MyCustomClose" Icon="@IconName.Close" OnClick="@MyCustomCloseHandler" />
    </WindowActions>
</TelerikWindow>

@code {
    bool isVisible { get; set; }
    string result { get; set; }

    void VisibleChangedHandler(bool currVisible)
    {
        // if you don't do this, the window won't close because of the user action
        // so if you don't update the view-model here, the window will not close when Esc is pressed

        //isVisible = currVisible;

        result = $"the window is now visible: {isVisible}";

        Console.WriteLine($"Closing because of Esc key");
    }

    void MyCustomCloseHandler()
    {
        //will fire on click only
        isVisible = false;
        //since the built-in window UI didn't invoke this change, the event will not fire
    }

    public void ToggleWindow()
    {
        isVisible = !isVisible;

        result = $"the window is now visible: {isVisible}";
    }
}

---

I would imagine most applications would use the Alert, Confim, Prompt concepts so it would be nice if they were built in.
It would further be nice if they were styleable and callable from c# code very similar to the wpf.
Of course as a default they could follow whatever css style is being used already.

RadWindow.Alert(text);
RadWindow.Confirm(text, () => {});
RadWindow.Prompt(text, result => {});

https://docs.telerik.com/devtools/wpf/controls/radwindow/features/predefined-dialogs

At the moment, a second modal window does not "block" the first.

For example, a static variable in aTelerik Window class can be used to track the z-index and render the dialog and modal background with increasing values when a new one is shown.

If you have other suggestions on handling the situation, share them below. Also, comment whether you would like that static class/variable to be public so you can set its initial value.

---

admin edit

At the moment this is not guaranteed and if you want to customize the behavior you should use a custom action to get the OnClick handler, and control the window through its parameters.

Here is an example of implementing a custom close button that also fires an event:

<TelerikWindow Visible="@IsWindowVisible" Modal="true" Centered="true">
    <WindowTitle>WindowTitle</WindowTitle>
    <WindowContent>
        lorem ipsum
    </WindowContent>
    <WindowActions>
        <WindowAction Name="MyCustomAction" Icon="close" OnClick="@HandleCancel" />
    </WindowActions>
</TelerikWindow>

@code{
    bool IsWindowVisible { get; set; } = true;

    async Task HandleCancel()
    {
        Console.WriteLine("my custom click happened");
        IsWindowVisible = false;//hide the window with your own code if you also want to do that
    }
}

Can we please have an [Open] or [Init] or [OnVisible] event exposed for Blazor Windows?

There is a whole bunch of stuff that I need to do in a Window (e.g. custom modal editing form that needs a lot of temporary supporting data structures) and I am having to do the work in a method that that opens the window, before the Window is opened and passing many data structures to the Window as parameters (there could be more than 20 of these). This is messy.

It would be much simpler, neater and efficient to have the Window create these resources on the fly when the Window is made visible and to dispose of them when the window closes. I would then only need to pass a few essential parameters.

I'm guessing this is a new feature request because I cannot see any way of detecting, in the code for a Window, that it has just been opened (or am I missing something?).

Kind regards,

Paul