在HTML畫布中的關鍵敏感度

Question

我需要知道在釋放鼠標/按鍵之前多長時間纔會按下鼠標/按鍵，因此響應將取決於按鍵/鼠標按鍵。

例如，我試過這個，但由於某種原因，它似乎沒有工作。

var time = new Date(); 
var mousedown, mouseup, mousehold; 

document.addEventListener('onmousedown', function(){ 
    mousedown = time.getTime(); //gets time when mouse was pressed 
}); 

document.addEventListener('onmouseup', function(){ 
    mouseup = time.getTime(); //time when mouse was released 
    mousehold = mouseup - mousedown; //time difference 
    console.log(mousehold); 
}); 

Answer 1

首先，你應該使用

document.addEventListenter("mousedown", function() {...}); 

和

document.addEventListener("mouseup", function() {...}); ' 

其次，你time.getTime將得到time變量的時間。 你應該這樣做：

var mousedown, mouseup, mousehold; 
 

 
document.addEventListener('mousedown', function(){ 
 
    mousedown = Date.now(); //gets time when mouse was pressed 
 
}); 
 

 
document.addEventListener('mouseup', function(){ 
 
    mouseup = Date.now(); //time when mouse was released 
 
    mousehold = mouseup - mousedown; //time difference 
 
    console.log(mousehold); 
 
});

這裏是一個更好的版本：

var mouseup, mousehold; 
 

 
document.addEventListener('mousedown', function(){ 
 
    mousedown = Date.now(); //gets time when mouse was pressed 
 
}); 
 

 
document.addEventListener('mouseup', function(){ 
 
    mousehold = Date.now()- mousedown; //time difference 
 
    console.log(mousehold); 
 
});

是沒有用的，如果你只是想鼠標鬆開變量來計算鼠標變量。