Javascript 角度合并少数图像
是否有任何选项将几个图像合并在一起。我看到一个用HTML5编码的,但我无法让它工作Javascript 角度合并少数图像,javascript,angular,typescript,html5-canvas,Javascript,Angular,Typescript,Html5 Canvas,是否有任何选项将几个图像合并在一起。我看到一个用HTML5编码的,但我无法让它工作 <canvas id="canvas"></canvas> <script type="text/javascript"> var canvas = document.getElementById('canvas'); var context = canvas.getContext('2d'); Image img1 = new Image(); Image i
<canvas id="canvas"></canvas>
<script type="text/javascript">
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
Image img1 = new Image();
Image img2 = new Image();
img1.onload = function () {
canvas.width = img1.width;
canvas.height = img1.height;
img2.src = 'imgfile2.png';
};
img2.onload = function () {
context.globalAlpha = 1.0;
context.drawImage(img1, 0, 0);
context.globalAlpha = 0.5; //Remove if pngs have alpha
context.drawImage(img2, 0, 0);
};
img1.src = 'imgfile1.png';
</script>
var canvas=document.getElementById('canvas');
var context=canvas.getContext('2d');
图像img1=新图像();
图像img2=新图像();
img1.onload=函数(){
canvas.width=img1.width;
canvas.height=img1.height;
img2.src='imgfile2.png';
};
img2.onload=函数(){
context.globalAlpha=1.0;
drawImage(img1,0,0);
context.globalAlpha=0.5;//如果PNG具有alpha,则删除
drawImage(img2,0,0);
};
img1.src='imgfile1.png';
只需在一个角度分量中使用它生成一个函数,然后使用一个局部变量来获取画布
@ViewChild('canvas') canvas: ElementRef;
mergeImages() {
var canvas: HTMLCanvasElement = this.canvas.nativeElement;
var context = canvas.getContext('2d');
let img1 = new Image();
let img2 = new Image();
img1.onload = function() {
canvas.width = img1.width;
canvas.height = img1.height;
img2.src = 'imgfile2.png';
};
img2.onload = function() {
context.globalAlpha = 1.0;
context.drawImage(img1, 0, 0);
context.globalAlpha = 0.5; //Remove if pngs have alpha
context.drawImage(img2, 0, 0);
};
img1.src = 'imgfile1.png';
}
在HTML中,记住声明局部变量
<canvas #canvas></canvas>
谢谢你的回答,但它似乎不起作用。(webstorm)在编解码器中给出错误的IDE找不到img1。然后我添加了这个变量img1:HTMLImageElement;并将img1添加为“Image this.img1=new Image();”,但IIDE在“Image”附近给出了错误“预期换行符或分号”。我试图删除“图像”,但它没有正常工作。我正在使用angular Cli。是的,对不起,我只是复制粘贴了你的代码。我编辑了我的答案,这应该有用。再次感谢你的帮助。现在在“@ViewChild('canvas')canvas上只有一个错误:ElementRef;”它在canvas下给出了错误。错误消息是未使用的标签。我试着删除它,但没有成功。你是否像我用标签一样给画布加了一个局部变量?