fixed sprite alpha can not change

[zhefengzhang]

Re: #
native 平台中，sprite 组件在没有 spriteFrame 时无法设置透明度值，需要在 sprite 组件更新 spriteFrame 时让其更新一次透明度值并作用到 ui 渲染上。
In native platform, sprite component can't set transparency value without spriteFrame. You need to let sprite component update transparency value once when spriteFrame is updated and apply it to ui rendering.

test bug code:

import { _decorator, Component, Node, Sprite, SpriteFrame } from 'cc';
const { ccclass, property } = _decorator;

@ccclass('NewComponent')
export class NewComponent extends Component {

    @property(Sprite)
    testSp: Sprite = null;

    @property(SpriteFrame)
    testSpf: SpriteFrame = null;

    start() {
        this.node.on(Node.EventType.TOUCH_END, this.test, this);
    }

    test () {
        if(this.testSp){
            var targetColor = this.testSp.color.clone();
            targetColor.a = 30;
            this.testSp.color = targetColor;
            setTimeout(()=>{
                this.testSp.spriteFrame = this.testSpf;
                console.log(`target Color alpha is ${this.testSp.color.a}`);
            })
        }
    }
}

[github-actions]

Code Size Check Report

Wechat (WASM)	Before	After	Diff
2D Empty (legacy pipeline)	1009805 bytes	1009779 bytes	👍 -26 bytes
2D All (legacy pipeline)	2675364 bytes	2675338 bytes	👍 -26 bytes
2D All (new pipeline)	2767100 bytes	2767074 bytes	👍 -26 bytes
(2D + 3D) All	10024070 bytes	10024044 bytes	👍 -26 bytes

Web (WASM + ASMJS)	Before	After	Diff
(2D + 3D) All	16843132 bytes	16843106 bytes	👍 -26 bytes

Interface Check Report

This pull request does not change any public interfaces !

[zhefengzhang]

@cocos-robot run test cases

[zhefengzhang]

@cocos-robot run test cases

[github-actions]

@zhefengzhang, Please check the result of run test cases:

• Test Platform: PR-Test
• Editor Version: v3.8.8
• Task Result: FAIL
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/decd132e-8802-44ae-8d35-c914eed36ce1/-1
• GitHub Action: https://github.com/cocos/cocos-engine/actions/runs/18934405291

Task Details

Platform	build	boot	runned	crashScene	FailScene
web-mobile	PASS	PASS	PASS
ios	PASS	PASS	FAIL		rt-read-pixels
mac	PASS	PASS	PASS

[github-actions]

@zhefengzhang, Please check the result of run test cases:

• Test Platform: PR-Test
• Editor Version: v3.8.8
• Task Result: PASS
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/1363349a-58a2-4640-bcd4-c735ec230cae/-1
• GitHub Action: https://github.com/cocos/cocos-engine/actions/runs/18934405291

Task Details

[sushanhong]

@cocos-robot run test cases

[zhefengzhang]

补测试 ios 平台（已通过）：https://cctest.cocos.org/#/reportview/PR-TEST/eaaed24d-69c6-4722-a95a-da46bd587422/-1~