Canvas 如何将从画布生成的300 x 150的图像大小调整为640px 480px
如何将从画布生成的300 x 150的图像大小调整为640 x 480 px,然后在base 64中发送新图像640 x 480 因为他这样做了,但我失去了图像,因为它出现在黑色背景上 请帮忙 这是我的javascript代码:Canvas 如何将从画布生成的300 x 150的图像大小调整为640px 480px,canvas,image-resizing,Canvas,Image Resizing,如何将从画布生成的300 x 150的图像大小调整为640 x 480 px,然后在base 64中发送新图像640 x 480 因为他这样做了,但我失去了图像,因为它出现在黑色背景上 请帮忙 这是我的javascript代码: var context = document.getElementById(idCanvas); // Canvas with image in 300 x 150 var canvasNew = document.getElementById("canva
var context = document.getElementById(idCanvas); // Canvas with image in 300 x 150
var canvasNew = document.getElementById("canvasToResize"); // Canvas to re-draw with new sizes
canvasNew.width= 640;
canvasNew.height = 480;
var context2 = canvasNew.getContext("2d");
var image = document.getElementById("newIMG"); // IMG tag for new image with new sizes
image.onload = function() {
context2.drawImage(image, 0, 0, 640, 480);
};
image.src = context.toDataURL();
return canvasNew.toDataURL().split(',')[1]; // send base 64
我能修好它。。。。如果他们有类似的问题,我为您需要的解决方案添加了代码
function canvasPreparedToShipping(canvasSource, canvasDestiny) {
var canvasS = document.getElementById(canvasSource); // Canvas with image 300 x 150
var finalImageResize = "";
var canvasIMG = document.getElementById(canvasDestiny); // Canvas to resize image
canvasIMG.width= 640;
canvasIMG.height = 480;
var context2 = canvasIMG.getContext("2d");
var image = document.getElementById("encodeIMG"); // hidden tag for new image
image.onload = function() {
context2.drawImage(image, 0, 0, 640, 480);
finalImageResize = canvasIMG.toDataURL().split(',')[1];
};
image.src = canvasS.toDataURL();
return finalImageResize; // Image in base64, ready to send the server
}