鸿蒙9+在TV端焦点封装控制

鸿蒙9+ 目前不支持鸿蒙系统电视，但是往后肯定是必须会支持的，所以直接学arkts就完事了，目前的api9+对焦点控制还是不够直接简洁，估计还在完善中，但是可以通过自定义component来实现一下
首先踩坑：

1. Row官方说自身属性是可获焦的，但是单独使用是没法获焦的，所以必须在里面添加一个可获焦的子view，但是通常所有的子view都是由获焦和离焦状态的，所以不能所有的子view都加上focusable=true，这里可以通过@Consume来同步整个组件内部的焦点状态, 注意这个修饰符达到同步的前提是参数名一模一样！！！

@Component export struct RowFocusable {    compWidth: Length = '90vp'   compHeight: Length = '28vp'   compBorderRadius: Length = '14vp'   alignItems: VerticalAlign = VerticalAlign.Center   justifyContent: FlexAlign = FlexAlign.Center    @Consume focusState: number    @Builder doAddChild(){}   @BuilderParam addChild: () => void = this.doAddChild;    build() {     Row() {       //扯淡的玩意，容器布局的子节点没有获焦能力的话，容器布局就不会获焦，       //但是子节点能获焦的话，那其他所有有焦点态的子节点也必须设置可获焦，那走焦的时候会在子节点之间走动，不合理，非常的不合理，       //竟然没有父组件拦截焦点的方法       Text('').focusable(true)         .onFocus(()=>{           this.focusState = ComponentsConstants.FOCUS_STATE_FOCUSED         })         .onBlur(()=>{           this.focusState = ComponentsConstants.FOCUS_STATE_NORMAL         }).width('0vp')       this.addChild()     }     .width(this.compWidth).height(this.compHeight)     .justifyContent(this.justifyContent)     .alignItems(this.alignItems)     .focusOnTouch(true)     .borderWidth(2)     .borderRadius(this.compBorderRadius)     .borderStyle(BorderStyle.Solid)     .onFocus(()=>{     })     .onBlur(()=>{     })     .stateStyles({       focused: {         .backgroundColor($r('app.color.transparent')       },       normal: {         .backgroundColor($r('app.color.transparent')       },     })   } } 

自定义component 后面直接设置基础属性，像上面这种只有一个@BuildParam方法的可以直接这样写，在大括号后面接上需要添加的子组件即可：

@Component export struct ImageButton {   btnWidth: Length = '90vp'   btnHeight: Length = '28vp'   imgWidth: Length = '15vp'   imgHeight: Length = '15vp'   tvCfg: TextFocusConfig | undefined = undefined   imgCfg: ImageFocusConfig | undefined = undefined   @Provide focusState: number = ComponentsConstants.FOCUS_STATE_NORMAL    @Builder buildImage() {     ImageFocusable({imgCfg: this.imgCfg}).width(this.imgWidth).height(this.imgHeight)   }    @Builder buildText() {     TextFocusable({tvCfg: this.tvCfg})   }    build() {     RowFocusable({ compWidth: this.btnWidth, compHeight: this.btnHeight }) {       this.buildImage()       this.buildText()     }   } }  //自定义，统一设置占位图 @Component export struct ImageFocusable {    @Consume focusState: number   imgCfg: ImageFocusConfig|undefined    build() {     Image(this.focusState==ComponentsConstants.FOCUS_STATE_FOCUSED ? this.imgCfg.imgResFocused : this.imgCfg.imgResNormal)       .objectFit(ImageFit.Contain)       .enabled(true)       .alt($r('app.media.poster_placeholder'))   } }  //这里定义成config类，是为了方便组件层级太深时，更好的透传，比如上面ImageButton export class ImageFocusConfig {   imgResNormal: ResourceStr   imgResFocused: ResourceStr    constructor(imgResNormal,imgResFocused) {     this.imgResNormal = imgResNormal     this.imgResFocused = imgResFocused   } }  @Component export struct TextFocusable {   @Consume focusState: number    tvCfg: TextFocusConfig | undefined    build() {     if (this.tvCfg != null) {       Text(this.tvCfg!.text)         .fontColor(this.focusState == ComponentsConstants.FOCUS_STATE_FOCUSED ? this.tvCfg!.focusColor : this.tvCfg.normalColor)         .textAlign(this.tvCfg.textAlign)         .maxLines(this.tvCfg.maxLine)         .textOverflow({overflow: this.tvCfg.textOverFlow})         .align(Alignment.Center)         .width(this.tvCfg.width)         .height(this.tvCfg.height)         .fontSize(this.tvCfg.textSize)     }   } }  export class TextFocusConfig {   text: ResourceStr   textSize: Length   width: Length   height: Length   normalColor: ResourceColor   focusColor: ResourceColor   selectColor: ResourceColor   textAlign: TextAlign   maxLine: number   textOverFlow: TextOverflow    constructor()   constructor(text?)   constructor(text?, tvSize?)   constructor(text?, tvSize?, width?, height?)   constructor(text?, tvSize?, width?, height?, normalColor?, focusColor?, selectColor?)   constructor(text?, tvSize?, width?, height?, normalColor?, focusColor?, selectColor?, textAlign?, maxLine?, textOverFlow?) {     this.text = text ?? ''     this.textSize = tvSize ?? '14vp'     this.width = width ?? 'auto'     this.height = height ?? 'auto'     this.normalColor = normalColor ?? $r('app.color.white_70')     this.focusColor = focusColor ?? $r('app.color.white_100')     this.selectColor = selectColor ?? $r('app.color.tv_color_selected')     this.textAlign = textAlign ?? TextAlign.Start     this.maxLine = maxLine ?? 1     this.textOverFlow = textOverFlow ?? TextOverflow.Ellipsis   }    setText(text): TextFocusConfig {     this.text = text     return this   }    setTextSize(size): TextFocusConfig {     this.textSize = size     return this   }    setWith(w): TextFocusConfig {     this.width = w     return this   }    setHeight(h): TextFocusConfig {     this.height = h     return this   } }  

像自定义text这种组件，很多属性都没法直接设置，所以需要添加自己命名的属性，然后也没有焦点态的方法，所以只能通过@Consume focusState: number 来同步父子组件之间的焦点状态，另外封装成config的好处还是挺多的，自我挖掘吧