button.md

Button Component Reference

The button component responds to a click from the user. When the user clicks a Button, its status will change. In addition, users can assign a custom behavior to buttons' click event.

Click the Add Component button at the bottom of the Properties panel and select Button from UI Component. Then you can add the Button component to the node.

Button Property

Property	Function explanation
Interactable	Boolean type, if set to false then the Button component enters the forbidden state.
Enable Auto Gray Effect	Boolean type, if set to true, the Button's target sprite will turn gray when interactable is false.
Transition	Enumeration type, including NONE, COLOR, SPRITE and SCALE. Each type corresponds to a different Transition setting. Please see the Button Transition section below for details.
Click Event	Default list type is null. Each event added by the user is composed of the node reference, component name and a response function. Please see the Button Click Event section below for details.

Note: When Transition is SPRITE and the disabledSprite property has a spriteFrame associated with it, the Enable Auto Gray Effect property is ignored at this time.

Button Transition

Button Transition is used to indicate the status of the Button when clicked by the user. Currently the types available are NONE, COLOR, SPRITE and SCALE.

Color Transition

Property	Function Explanation
Normal	Color of Button under Normal status.
Pressed	Color of Button under Pressed status.
Hover	Color of Button under Hover status.
Disabled	Color of Button under Disabled status.
Duration	Time interval needed for Button status switching.

Sprite Transition

Property	Function Explanation
Normal	SpriteFrame of Button under Normal status.
Pressed	SpriteFrame of Button under Pressed status.
Hover	SpriteFrame of Button under Hover status.
Disabled	SpriteFrame of Button under Disabled status.

Scale Transition

Property	Function Explanation
Duration	Time interval needed for Button status switching.
ZoomScale	When user press the button, the button will zoom to a scale. The final scale of the button equals button original scale * zoomScale, zoomScale could be negative value.

Button Click Event

The Button can additionally add a Click event to respond to the player's click action. There are two ways to do this.

Add a callback through the Properties.

No.	Property	Function Explanation
1	Target	Node with the script component.
2	Component	Script component name.
3	Handler	Assign a callback function which will be triggered when the user clicks the Button.
4	customEventData	A user-defined string value passed as the last event argument of the event callback.

Add a callback through the script.

There are two ways to add a callback through the script.

1. The event callback added by this method is the same as the event callback added by the editor, all added by code. First you need to construct a cc.Component.EventHandler object, and then set the corresponding target, component, handler and customEventData parameters.

   // here is your component file, file name = MyComponent.js 
   cc.Class({
       extends: cc.Component,
       properties: {},
   
       onLoad: function () {
           var clickEventHandler = new cc.Component.EventHandler();
           clickEventHandler.target = this.node; // This node is the node to which your event handler code component belongs
           clickEventHandler.component = "MyComponent";// This is the code file name
           clickEventHandler.handler = "callback";
           clickEventHandler.customEventData = "foobar";
   
           var button = this.node.getComponent(cc.Button);
           button.clickEvents.push(clickEventHandler);
       },
   
       callback: function (event, customEventData) {
           // here event is a Event object, you can get events sent to the event node node
           var node = event.target;
           var button = node.getComponent(cc.Button);
           // here the customEventData parameter is equal to you set before the "foobar"
       }
   });

2. By button.node.on ('click', ...) way to add, this is a very simple way, but the way there are some limitations in the event callback which can not gets the screen coordinate point of the current click button.

   // Suppose we add an event handler callback to the onLoad method of a component and handle the event in the callback function:
   
   cc.Class({
       extends: cc.Component,
   
       properties: {    
           button: cc.Button
       },
   
       onLoad: function () {
           this.button.node.on('click', this.callback, this);
       },
   
       callback: function (button) {
           // do whatever you want with button
           // In addition, attention to this way registered events, can not pass customEventData
       }
   });

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Continue on to read about ProgressBar Component reference.