在我的代码中，我只得到定义宽度和高度的黑色 Canvas 。并且红色和白色未在屏幕上呈现。
提前致谢。
var canvas;
var canvasContext;
var ballx = 50;
window.onload = function() {
canvas = document.getElementById('gameCanvas');
canvasContext = canvas.getContext('2d');
drawCanvas();
drawCanvasRed();
// drawCanvas();
}
function drawCanvas() {
canvasContext.fillStyle = 'black';
canvasContext.fillRect(0, 0, canvas.width, canvas.height);
canvasContext.fillStyle = 'white';
canvasContext.fillRect(225, 200, 50, 25);
};
function drawCanvasRed() {
canvasContext.fillStyle = 'red';
canvasContext.fillRect(ballx, 200, 50, 25);
}#gameCanvas {
width: 500px;
height: 500px;
}<canvas id="gameCanvas"></canvas>最佳答案
您需要检查 Canvas 的大小。我改变了一些尺寸。所以它可以帮助你。
<!DOCTYPE html>
<html>
<head></head>
<style>
#gameCanvas {
width: 1000px;
height: 1000px;
}
</style>
<body>
<canvas id="gameCanvas"></canvas>
<script>
var canvas;
var canvasContext;
var ballx = 50;
window.onload = function() {
canvas = document.getElementById('gameCanvas');
canvasContext = canvas.getContext('2d');
drawCanvas();
drawCanvasRed();
// drawCanvas();
}
function drawCanvas() {
canvasContext.fillStyle = 'black';
canvasContext.fillRect(0, 0, 500, 500); // In your size you need to check, because you passed canvas width and canvas height
canvasContext.fillStyle = 'white';
canvasContext.fillRect(10, 10, 50, 25);
};
function drawCanvasRed() {
canvasContext.fillStyle = 'red';
canvasContext.fillRect(ballx, 50, 50, 25);
}
</script>
</body>
</html>
关于javascript - 无法通过 HTML 在屏幕上显示 Canvas，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59320915/