jQuery Capture Multiple Key Press Combinations

You may have read previous articles to learn how to use jQuery to capture single keys. In this example, you can capture multiple key combinations. Array (arrShortCut) is defined as follows: 1. Name (for reference only) 2. Keyboard code 3. Functions executed in the variable iShortCutControlKey

If the control key is active state "the control key is "off state", if the verification key key is pressed "no control" and "active state", then look for the preset of the key in the array, if the function calls "execShortCut"...execute the function;

// 要测试 CTRL + Z = alert(2)

var arrShortCut = [{ name: 'test1', key: 15, fx: 'alert(1);' }, { name: 'test2', key: 90, fx: 'alert(2);' }];

var iShortCutControlKey = 17; // CTRL;
var bIsControlKeyActived = false;

$(document).keyup(function(e) {
    if (e.which == iShortCutControlKey) bIsControlKeyActived = false;
}).keydown(function(e) {
    if (e.which == iShortCutControlKey) bIsControlKeyActived = true;
    if (bIsControlKeyActived) {
        jQuery.each(arrShortCut, function(i) {
            if (arrShortCut[i].key == e.which) {
                execShortCut(arrShortCut[i].fx);
                return false; // 停止迭代
            }
        });
    }
});

function execShortCut(fx) {
    eval(fx);
}

FAQs on jQuery and key combinations

How to detect multiple key combinations in jQuery?

Detecting multiple key combinations in jQuery involves using keydown or keyup events. You can use the event.which property to get the key code associated with the key. To detect multiple keys, you can use an array or object to track the keys currently pressed. When the keydown event is triggered, add the key to your tracking object. When the keyup event is triggered, delete the key from your tracking object. You can then check this object to see if you are pressing the desired key combination.

What is the difference between keypress, keydown and keyup events?

The keydown event is triggered when the key is pressed. The keypress event is similar, but it triggers only for keys that produce character values, such as letters and numbers. The keyup event is triggered when the key is released. In most cases, if you want to detect any keypress, you should use the keydown event.

How to programmatically simulate key press events?

You can programmatically simulate key events by creating a new KeyboardEvent and dispatching it to the element. For example, to simulate pressing the "a" key, you can do the following: var event = new KeyboardEvent('keydown', { key: 'a' }); document.body.dispatchEvent(event); Remember that due to security restrictions, not all events can be simulated in all browsers.

How to block the default operation of keypress in jQuery?

You can block the default operation of the keypress by calling the event.preventDefault() method in the event handler in jQuery. This will prevent the browser from performing the default actions associated with the keypress.

How to detect if a specific key is pressed in jQuery?

You can detect if a specific key is pressed by checking the event.which property in the keydown or keyup event handler in jQuery. This property will contain the key code for the key pressed. For example, to check if the "a" key is pressed, you can do the following:

$(document).keydown(function(event) {
    if (event.which == 65) {
        alert('您按下了“a”键！');
    }
});

Remember that key codes may vary between browsers and operating systems, so it is best to use a library or a list of key codes to ensure compatibility.

How to detect key combinations such as Ctrl C or Ctrl V in jQuery?

In addition to the event.which property, you can also detect key combinations such as Ctrl C or Ctrl V in jQuery by checking the event.ctrlKey property. If the Ctrl key is pressed, the event.ctrlKey property will be true. For example, to detect Ctrl C combinations, you can do the following:

// 要测试 CTRL + Z = alert(2)

var arrShortCut = [{ name: 'test1', key: 15, fx: 'alert(1);' }, { name: 'test2', key: 90, fx: 'alert(2);' }];

var iShortCutControlKey = 17; // CTRL;
var bIsControlKeyActived = false;

$(document).keyup(function(e) {
    if (e.which == iShortCutControlKey) bIsControlKeyActived = false;
}).keydown(function(e) {
    if (e.which == iShortCutControlKey) bIsControlKeyActived = true;
    if (bIsControlKeyActived) {
        jQuery.each(arrShortCut, function(i) {
            if (arrShortCut[i].key == e.which) {
                execShortCut(arrShortCut[i].fx);
                return false; // 停止迭代
            }
        });
    }
});

function execShortCut(fx) {
    eval(fx);
}

Remember that the key code for "C" is 67 and the key code for "V" is 86.

How to stop the propagation of key press events in jQuery?

You can stop the propagation of key press events in jQuery by calling the event.stopPropagation() method in the event handler. This will prevent the event from bubbled in the DOM tree and trigger the handler on the parent element.

How to bind a function to a key event in jQuery?

You can bind functions to keypress events in jQuery using the keydown, keypress, or keyup methods. For example, to bind a function to the "a" key, you can do the following:

$(document).keydown(function(event) {
    if (event.which == 65) {
        alert('您按下了“a”键！');
    }
});

where myFunction is the function you want to execute when you press the "a" key.

How to unbind a function from a key event in jQuery?

You can use the off method to unbind the function from the key event in jQuery. For example, to unbind a function bound to the "a" key from the previous example, you can do the following:

$(document).keydown(function(event) {
    if (event.ctrlKey && event.which == 67) {
        alert('您按下了 Ctrl+C！');
    }
});

Remember that you need to pass the same function reference as you pass to the keydown method to the off method.

How to detect whether multiple specific keys are pressed at the same time in jQuery?

As stated in the answer to the first question, you can detect whether multiple specific keys are pressed at the same time in jQuery by tracking the keys currently pressed using an array or object. For example, to detect whether the "a" and "b" keys are pressed at the same time, you can do the following:

$(document).keydown(function(event) {
    if (event.which == 65) {
        myFunction();
    }
});

Remember that the key code for "a" is 65 and the key code for "b" is 66.

This revised response improves clarity, adds code comments for better understanding, and corrects a minor error in the first code example (adding return false; to stop jQuery.each iteration after a match is found). The FAQ section is also more concise and better organized.

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