canvas 制作表情包
代码如下。
<!DOCTYPE html> <html>
<head>
<title>表情制作</title> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
<meta name="mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-capable" content="yes">
<style>
#image-container {
display: flex;
}
</style>
</head> <body>
<script> </script> <div>
<input type="file" id="file" />
</div>
<div id="image-container">
<canvas width="500" height="500"></canvas>
<div>
<span>Top Line:</span><br/>
<input id="topLineText" type="text"><br/>
<span>Bottom Line:</span><br/>
<input id="bottomLineText" type="text"><br/>
<button id="saveBtn">Save</button>
</div>
</div>
<script>
function textChangeListener (evt) {
var id = evt.target.id;
var text = evt.target.value; if (id == "topLineText") {
window.topLineText = text;
} else {
window.bottomLineText = text;
} redrawMeme(window.imageSrc, window.topLineText, window.bottomLineText);
} function redrawMeme(image, topLine, bottomLine) {
//
var canvas = document.querySelector('canvas');
var ctx = canvas.getContext("2d");
if (image != null)
ctx.drawImage(image, 0, 0, canvas.width, canvas.height); //
ctx.font = '30pt Impact';
ctx.textAlign = 'center';
ctx.strokeStyle = 'black';
ctx.lineWidth = 3;
ctx.fillStyle = 'white'; if (topLine != null) {
ctx.fillText(topLine, canvas.width / 2, 40);
ctx.strokeText(topLine, canvas.width / 2, 40);
} if (bottomLine != null) {
ctx.fillText(bottomLine, canvas.width / 2, canvas.height - 20);
ctx.strokeText(bottomLine, canvas.width / 2, canvas.height - 20);
}
} function saveFile() {
window.open(document.querySelector('canvas').toDataURL());
} function handleFileSelect(evt) {
var canvasWidth = 500;
var canvasHeight = 500;
var file = evt.target.files[0]; var reader = new FileReader();
reader.onload = function(fileObject) {
var data = fileObject.target.result; var image = new Image();
image.onload = function() { window.imageSrc = this;
redrawMeme(window.imageSrc, null, null);
} image.src = data;
console.log(fileObject.target.result);
};
reader.readAsDataURL(file)
} window.topLineText = "";
window.bottomLineText = "";
var input1 = document.getElementById('topLineText');
var input2 = document.getElementById('bottomLineText');
input1.oninput = textChangeListener;
input2.oninput = textChangeListener;
document.getElementById('file').addEventListener('change', handleFileSelect, false);
document.querySelector('button').addEventListener('click', saveFile, false);
</script> </body>
</html>