Tutorial on converting canvas to image example-H5 Tutorial-php.cn

Tutorial on converting canvas to image example

巴扎黑

Release： 2017-05-27 10:12:36

Original

1826 people have browsed it

Sometimes, we want to store the drawn canvas as a local image. What should we do? Canvas provides an important method toDataURL(), which can convert the pattern in the canvas into base64 encoding format. png or other format pictures (according to the mine type parameters you passed in), and then return Data URL data. Next let's see how it is implemented.

A canvas canvas for the html page:

<canvas id="canvas"></canvas>
<button class="button-balanced" id="save">save</button>
<br />
<a href="" download="canvas_love.png" id="save_href">
    <img src="" id="save_img"/>
</a>

Copy after login

The corresponding js code implementation:

var c=document.getElementById("canvas");
function drawLove(canvas){
    let ctx = canvas.getContext("2d");
    ctx.beginPath();
    ctx.fillStyle="#E992B9";
    ctx.moveTo(75,40);
    ctx.bezierCurveTo(75,37,70,25,50,25);
    ctx.bezierCurveTo(20,25,20,62.5,20,62.5);
    ctx.bezierCurveTo(20,80,40,102,75,120);
    ctx.bezierCurveTo(110,102,130,80,130,62.5);
    ctx.bezierCurveTo(130,62.5,130,25,100,25);
    ctx.bezierCurveTo(85,25,75,37,75,40);
    ctx.fill();
}
drawLove(c); 

var butSave = document.getElementById("save");
butSave.onclick=function(){
    var svaeHref = document.getElementById("save_href");
    /*
     * 传入对应想要保存的图片格式的mime类型
     * 常见：image/png，image/gif,image/jpg,image/jpeg
     */
    var img = document.getElementById("save_img");
    var tempSrc = canvas.toDataURL("image/png");
    svaeHref.href=tempSrc; 
    img.src=tempSrc;  
};

Copy after login

After clicking the save button, the picture will be displayed. Click the picture to pop up the download dialog box.

The effect is as follows:

Tutorial on converting canvas to image example

The above is the detailed content of Tutorial on converting canvas to image example. For more information, please follow other related articles on the PHP Chinese website!