5

In an early version of Blazor there was an IHtmlInputElement interface with selectionStart and selectionEnd properties.

Can anyone explain how I can use these to get the selected text from a text input control in C#?

UPDATE Here's what I have so far.

@page "/selectedtext"
@inject IJSRuntime JsRuntime

<h3>TextSelection</h3>

<input type="text" placeholder="Type here" @ref="myTextInput"/>

<button class="btn btn-primary" @onclick="@(async () => await GetSelectionStart(myTextInput))"></button>

@code {
    public ElementReference myTextInput { get; set; }

    public async Task GetSelectionStart(ElementReference element)
    {
        int pos = await JsRuntime.InvokeAsync<int>("GetSelectedStart", element);
    }
}

// myscript.js
{
    getSelectedStart : function (element) {
        return element.selectionStart;
    }
}
phil
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1 Answers1

4
@page "/selectedtext"
@inject IJSRuntime JsRuntime

<h3>TextSelection</h3>

<input type="text" placeholder="Type here" @ref="myTextInput"/>

<button class="btn btn-primary" @onclick="@(async () => await GetSelectionStart(myTextInput))">Get Position</button>

@code {
    public ElementReference myTextInput { get; set; }

    public async Task GetSelectionStart(ElementReference element)
    {
        int pos = await JsRuntime.InvokeAsync<int>("getSelectedStart", element);
    }
}

// myscript.js
window.getSelectedStart = (element) => {
        return element.selectionStart;
    }

phil
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  • Yes, it works and is an answer. It has some subtle differences to what is in my question. – phil Feb 07 '20 at 12:19