Example to explore Vue’s event binding mechanism

Vue.js is a popular front-end framework that provides many convenient methods in event binding. In Vue, events can be bound through the v-on directive. In this article, we'll explore Vue's event binding mechanism and provide some examples of how to use it.

1. v-on directive

The v-on directive is used to bind events in Vue instances. Its basic syntax is as follows:

v-on: event name="event processing function"

or abbreviated as:

@event name="event processing function"

For example, we can bind a click event to a button:

<button v-on:click="handleClick">点击我</button>

Or use the abbreviation:

<button @click="handleClick">点击我</button>

The handleClick method here is a method defined in the Vue instance, Used to handle click events.

2. Binding method

Vue supports binding multiple types of events, including clicks, double-clicks, keyboard keys, mouse movements, etc. We can specify the type of event to bind by adding a modifier after the event name.

1. Click event

As shown above, we can use v-on:click or @click on the element to bind a click event. The handler function of the click event can be a simple method, for example:

methods: {
  handleClick () {
    console.log('Button clicked!')
  }
}

2. Double-click event

To bind the double-click event, we can add a .dbl modifier after the event name:

<button v-on:dblclick="handleDoubleClick">双击我</button>

methods: {
  handleDoubleClick () {
    console.log('Button double-clicked!')
  }
}

3. Keyboard events

You can use v-on:keydown, v-on:keypress, v-on:keyup to bind keyboard press, keyboard key, and keyboard release respectively. event. For example:

<input type="text" v-on:keyup.enter="handleEnterKey" placeholder="按 Enter 键触发">

methods: {
  handleEnterKey () {
    console.log('Enter key pressed!')
  }
}

4. Mouse movement event

You can use v-on:mousemove, v-on:mouseover, v-on:mouseout to bind mouse movement, mouse entry, and mouse respectively. Leave the event. For example:

<div v-on:mousemove="handleMousemove">移动鼠标来触发事件</div>

methods: {
  handleMousemove () {
    console.log('Mouse moved!')
  }
}

5. Other events

In addition to the above common events, Vue also provides many other types of event binding methods, such as v-on:scroll, v-on :submit etc. You can refer to the official documentation for more details.

3. Pass parameters

Sometimes we need to pass some parameters in the event processing function. We can use the $event parameter to get the event object, or we can use custom parameters to pass values.

1. Pass the event object

In the event processing function, $event can get the object that currently triggers the event. For example:

<button @click="handleClick($event)">点击我</button>

methods: {
  handleClick (event) {
    console.log(event.target)
  }
}

2. Pass custom parameters

Sometimes we need to pass some custom parameters to the event processing function, such as an ID or an index value. We can use v-bind: to bind properties to pass values. For example:

<button v-for="(item, index) in list" :key="item.id" @click="handleClick(item.id, index)">{{ item.title }}</button>

methods: {
  handleClick (id, index) {
    console.log('Item ID:', id)
    console.log('Item index:', index)
  }
}

4. Binding one-time events

Sometimes we only need to bind one-time events, then we can use the v-once command. For example:

<button v-once @click="handleClick">点击我</button>

The @click event here will only be triggered once, and then the button will become disabled.

5. Summary

Through the introduction of this article, we have learned about Vue’s event binding methods and some common event types and modifiers. I hope this article can help you with event binding in Vue development. If you have any questions, please leave a message in the comment area below for discussion.

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