Javascript 让画布元素在按住键的同时移动,然后在放开时停止
代码问题:如果您按住箭头键并查看控制台,则每次按键后都会触发上键。此外,按住箭头键后,对象停止移动 为什么在这种情况下这是一个问题:我希望每次启动箭头键向下时,正方形都会移动,然后在启动键向上时停止 想要的效果:我想按住一个键来移动盒子,然后当我放开键时它停止移动Javascript 让画布元素在按住键的同时移动,然后在放开时停止,javascript,keydown,keyup,Javascript,Keydown,Keyup,代码问题:如果您按住箭头键并查看控制台,则每次按键后都会触发上键。此外,按住箭头键后,对象停止移动 为什么在这种情况下这是一个问题:我希望每次启动箭头键向下时,正方形都会移动,然后在启动键向上时停止 想要的效果:我想按住一个键来移动盒子,然后当我放开键时它停止移动 这是可以实现的吗?如果是,大约如何?如果没有,是否有其他方法登记方向 作为记录,我不想使用Jquery。谢谢你的建议 Javascript keyLeft = 0; keyRight = 0; keyNorth = 0; keyB
- 这是可以实现的吗?如果是,大约如何?如果没有,是否有其他方法登记方向
keyLeft = 0;
keyRight = 0;
keyNorth = 0;
keyBot = 0;
var interval;
var c = 0;
window.onload=function(){
addButton.addEventListener
('click',function(){addRowCell("table1")},false);
removeButton.addEventListener
('click',function(){deleteRowCell("table1")},false);
stopButton.addEventListener('click',stop,false);
startButton.addEventListener('click',initiate,false);
}
//38 up
//37 left
//40 down
//39 right
document.onkeydown = function (e) {
console.debug(e.keyCode, "down");
console.debug(e.keyCode, "up");
switch (e.keyCode){
case 37:
initiateLeft();
break;
case 38:
initiateNorth();
break;
case 40:
initiateBot();
break;
case 39:
initiateRight();
break;
case 32:
stop();
break;
}
}
function stop(){
clearInterval(interval);
}
function initiateRight(){
clearInterval(interval);
interval = setInterval(right,100);
}
function initiateLeft(){
clearInterval(interval);
interval = setInterval(left,100);
}
function initiateNorth(){
clearInterval(interval);
c=0;
interval = setInterval(north,100);
}
function initiateBot(){
clearInterval(interval);
interval = setInterval(bot,100);
}
function right(){
var x = document.getElementById("counter");
x.value = keyRight;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyRight++;
}
function left(){
var x = document.getElementById("counter");
x.value = keyLeft;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyLeft++;
}
function north(){
var x = document.getElementById("counter");
x.value = keyNorth;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
keyNorth+=(10-c);
c+=2;
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
if(20-keyNorth == 20)
clearInterval(interval);
}
function bot(){
var x = document.getElementById("counter");
x.value = keyBot;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyBot++;
}
HTML
按空格键暂停。
我希望我没有做你的家庭作业。如果是这样,你应该感到内疚
keyLeft = 0;
keyRight = 0;
keyNorth = 0;
keyBot = 0;
var interval;
var c = 0;
//38 up
//37 left
//40 down
//39 right
document.onkeydown = function (e) {
console.debug(e.keyCode, "down");
console.debug(e.keyCode, "up");
switch (e.keyCode){
case 37:
initiateLeft();
break;
case 38:
initiateNorth();
break;
case 40:
initiateBot();
break;
case 39:
initiateRight();
break;
case 32:
stop();
break;
}
}
function stop(){
}
function initiateRight(){
interval = setTimeout(right,100);
}
function initiateLeft(){
interval = setTimeout(left,100);
}
function initiateNorth(){
c=0;
interval = setTimeout(north,100);
}
function initiateBot(){
interval = setTimeout(bot,100);
}
function right(){
var x = document.getElementById("counter");
x.value = keyRight;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyRight++;
}
function left(){
var x = document.getElementById("counter");
x.value = keyLeft;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyLeft++;
}
function north(){
var x = document.getElementById("counter");
x.value = keyNorth;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
keyNorth+=(10-c);
c+=2;
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
}
function bot(){
var x = document.getElementById("counter");
x.value = keyBot;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyBot++;
}
@MindaugasVečkys如果这是你的意思,我已经在帖子中添加了HTML。如果你问我是否可以在代码中添加HTML,是的,那很好!哈哈,为什么你认为这是家庭作业xD?我正在为我的网站做一个小游戏。谢谢你的提示,尽管它很有效。@Genome314,你永远不知道。:)很高兴看到它对你有帮助。
keyLeft = 0;
keyRight = 0;
keyNorth = 0;
keyBot = 0;
var interval;
var c = 0;
//38 up
//37 left
//40 down
//39 right
document.onkeydown = function (e) {
console.debug(e.keyCode, "down");
console.debug(e.keyCode, "up");
switch (e.keyCode){
case 37:
initiateLeft();
break;
case 38:
initiateNorth();
break;
case 40:
initiateBot();
break;
case 39:
initiateRight();
break;
case 32:
stop();
break;
}
}
function stop(){
}
function initiateRight(){
interval = setTimeout(right,100);
}
function initiateLeft(){
interval = setTimeout(left,100);
}
function initiateNorth(){
c=0;
interval = setTimeout(north,100);
}
function initiateBot(){
interval = setTimeout(bot,100);
}
function right(){
var x = document.getElementById("counter");
x.value = keyRight;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyRight++;
}
function left(){
var x = document.getElementById("counter");
x.value = keyLeft;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyLeft++;
}
function north(){
var x = document.getElementById("counter");
x.value = keyNorth;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
keyNorth+=(10-c);
c+=2;
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
}
function bot(){
var x = document.getElementById("counter");
x.value = keyBot;
var d = document.getElementById("canv1");
var ctx = d.getContext("2d");
var ctx1 = document.querySelector('#canv1').getContext('2d');
ctx1.clearRect(0,0,100,100);
ctx.strokeRect(20+keyRight-keyLeft,20-keyNorth+keyBot,40,40);
keyBot++;
}