我可以在画布中放一个HTML按钮吗？

Question

I want to make the buttons for the game I'm making as real HTML buttons, but they need to be inside the canvas.

How would I go about doing this?

Answer 1

Given that the canvas element has a transparent content model , it may contain fallback elements which are displayed in the event that the canvas element is unsupported. They will not be displayed if the canvas is supported.

You can position HTML elements relative to the canvas' parent to have the buttons "hovering" over the canvas. A menu element could be an appropriately semantic element to render a list of controls, depending on the context:

_HTML:

 <div id="container"> <canvas id="viewport"> </canvas> <menu id="controls"> </menu> </div> 

_CSS:

 #container { height: 400px; position: relative; width: 400px; } #viewport { height: 100%; width: 100%; } #controls { bottom: 0; left: 0; position: absolute; width: 100%; } 

Answer 2

You can put the button on top of the canvas by giving the canvas a z-index which is lower than the z-index of the button:

<canvas style="z-index:1"></canvas>
<input type="button" style="z-index:2; position:absolute; top:x; left:y" value="test"/>

where x and y are numbers.

Answer 3

画布中的HTML是不可能的，但也许你可以绝对定位你的元素，以便它们在画布上“漂浮”，但不在其中。

Answer 4

I don't believe you can 'put' HTML content inside a canvas tag. Whatever you put in there will actually be displayed if the browser doesn't support <canvas> .

You can, however, position your buttons absolutely over top of a canvas or render areas in your canvas that 'look' like buttons and handle the events yourself (a lot of work).

Answer 5

One way to add button dynamically on the top of the canvas is following the next two points: 1. Making zIndex of the button higher than canvas 2. Position the button using absolute positioning with desired top and left value

Jsfiddle: https://jsfiddle.net/n2EYw/398/

HTML:

<canvas id="canvas" width="200" height="200">           
 </canvas>

CSS:

canvas {
    border: 1px dotted black;
    background: navy;
}

JavaScript:

var $testButton = $('<input/>').attr({
    type: 'button',
    name: 'btn1',
    value: 'TestButton',
    id: 'testButton',
    style: 'position:absolute; top:50px;left:100px; zindex:2'
});
$('body').append($testButton);
$(document).on("click", "#testButton", function() {
    alert('button clicked');
});

Answer 6

HTML inside of canvas is not possible.
But if you really want to use buttons, why don't you try positioning the buttons on top of the canvas?

Answer 7

You can put a button inside the canvas (png, jpg, svg and text), using the Canvate library. http://www.sakuracode.com/canvate

Here you are a sample of a draging button inside the canvas.

container.startDrag();

https://codepen.io/EiseiKashi/pen/BxNbmj

Answer 8

You can use my DropdownMenu for put an HTML button or menu inside the canvas.

Example of code:

<div class="container" id="containerDSE">
    <canvas id="canvas"></canvas>
</div>
<script>
var elContainer = document.getElementById( "containerDSE" ),
elCanvas = elContainer.querySelector( 'canvas' );

dropdownMenu.create( [

    {

        name: 'Button',
        onclick: function ( event ) {

            var message = 'Button onclick';
            //console.log( message );
            alert( message )

        },

    },

], {

    elParent: elContainer,
    canvas: elCanvas,
    decorations: 'Transparent',

} );
</script>

Example of using.