How to check the current mouse button state Using Javascript [duplicate]

问题

I want the state of mouse on Down state or on up state

document.onmousemove = mouseMove;
document.onmousedown = mouseDown;
document.onmouseup   = mouseUp;

function mouseMove(ev) {

    mouseState="";
    //How can I know the state button of mouse button from here 
    if(mouseState=='down') {
        console.log('mouse down state')
    }

    if(mouseState=='up')  {
        console.log('mouse up state')
    }
}

function mouseDown(ev) {
    console.log('Down State you can now start dragging');
    //do not write any code here in this function
}

function mouseUp(ev) {
    console.log('up state you cannot drag now because you are not holding your mouse')
    //do not write any code here in this function
}

When I moved my mouse, program should show the required value of mouseState up or down on console for now

回答1:

You just have to create a variable for it.

document.onmousemove = mouseMove;
document.onmousedown = mouseDown;
document.onmouseup   = mouseUp;
var mouseState = "up";

function mouseMove(ev) {

    //How can I know the state of mouse from here 
    if(mouseState=='down') {
        console.log('mouse down state')
    }

    if (mouseState=='up')  {
        console.log('mouse up state')
    }
}

function mouseDown(ev) {
    mouseState = "down";
    console.log('Down State you can now start dragging');
    //do not write any code here in this function
}

function mouseUp(ev) {
    mouseState = "up";
    console.log('up state you cannot drag now because you are not holding your mouse')
    //do not write any code here in this function
}

You should have a look at the event on "mousemove", by logging it into the console. There might be a property there that shows that state of the mouse, just like the keypress event has a property which tells you if the shift button is pressed. But that might not be cross browser compatible.

回答2:

You could check the MouseEvent.which property.

function mouseMove(ev) {
    if(ev.which==1) {
        console.log('mouse down state with left click');
    } else if(ev.which==3)  {
        console.log('mouse down state with right click');
    } else {
        console.log('mouse update');
    } 
}

来源：https://stackoverflow.com/questions/12209483/how-to-check-the-current-mouse-button-state-using-javascript

标签

javascript

mousedown

mouseup