鸿蒙4.0实战教学—基础ArkTS（简易视频播放器）

构建主界面

主界面由视频轮播模块和多个视频列表模块组成，效果图如图：

VideoData.ets中定义的视频轮播图数组SWIPER_VIDEOS和视频列表图片数组HORIZONTAL_VIDEOS。

// VideoData.ets
import { HorizontalVideoItem } from './HorizontalVideoItem';
import { SwiperVideoItem } from './SwiperVideoItem';

export const SWIPER_VIDEOS: SwiperVideoItem[] = [
  new SwiperVideoItem($r('app.media.banner1')),
  new SwiperVideoItem($r('app.media.banner2')),
  new SwiperVideoItem($r('app.media.banner3'))
];

export const HORIZONTAL_VIDEOS: HorizontalVideoItem[] = [
  new HorizontalVideoItem(1, $r('app.media.video_list0'), '视频1'),
  new HorizontalVideoItem(2, $r('app.media.video_list1'), '视频2'),
  new HorizontalVideoItem(3, $r('app.media.video_list2'), '视频3')
];

IndexSwiper.ets文件中定义的轮播图子组件SwiperVideo，点击轮播图片，页面跳转到视频播放页面，并携带本地视频flag，效果图如图：

// IndexSwiper.ets
@Component
export struct SwiperVideo {
  build() {
    Column() {
      Swiper() {
        ForEach(SWIPER_VIDEOS, (item: SwiperVideoItem) => {
          SwiperItem({ imageSrc: item.image, source: $rawfile('videoTest.mp4') })
        }, (item: SwiperVideoItem) => JSON.stringify(item))
      }
      .autoPlay(true)
    }
    // 样式设置
    ...
  }
}

@Component
struct SwiperItem {
  private imageSrc: Resource = $r('app.string.empty');
  private source: Resource = $r('app.string.empty');
  private paramItem: ParamItem = new ParamItem();
  ...

  build() {
    // 跳转一：使用Navigator组件跳转到视频播放界面
    Navigator({ target: SECOND_PAGE, type: NavigationType.Push }) {
      Image(this.imageSrc)
        .borderRadius(MARGIN_FONT_SIZE.FIRST_MARGIN)
    }
    .params(this.paramItem)
  }
}

IndexModule.ets文件中定义的视频列表图片子组件VideoModule，点击子组件中的图片，页面跳转到视频播放页面，并携带网络视频flag，效果图如图：

// IndexModule.ets
@Component
export struct VideoModule {
  private moduleName: string = '';

  build() {
    Column() {
      // 视频列表上方的文本信息
      ...
      // 视频列表组件
      List({ space: MARGIN_FONT_SIZE.FIRST_MARGIN }) {
        ForEach(HORIZONTAL_VIDEOS, (item: HorizontalVideoItem) => {
          ListItem() {
            HorizontalItem({
              imageSrc: item.image,
              source: NET,
              videoName: item.name
            })
          }
        }, (item: HorizontalVideoItem) => JSON.stringify(item))
      }
      // 设置列表横向排列
      .listDirection(Axis.Horizontal)
    }
    // 样式设置
    ...
  }
}

@Component
struct HorizontalItem {
  private imageSrc: Resource = $r('app.string.empty');
  private source: string = '';
  private videoName: string = '';

  build() {
    // 跳转二：使用route跳转到视频播放界面
    Column() {
      Image(this.imageSrc)
        .width(MARGIN_FONT_SIZE.SEVENTH_MARGIN)
        .height(MARGIN_FONT_SIZE.SIXTH_MARGIN)
        .onClick(() => {
          router.pushUrl({
            url: SECOND_PAGE,
            params: { source: this.source }
          });
        })
     ...
    }
    .justifyContent(FlexAlign.Center)
  }
}

在SimpleVideoIndex.ets主界面中引用SwiperVideo和VideoModule子组件。

// SimpleVideoIndex.ets
@Entry
@Component
struct SimpleVideoIndex {
  build() {
    Column({ space: MARGIN_FONT_SIZE.FOURTH_MARGIN }) {
      // 视频轮播组件
      SwiperVideo()
      List() {
        ForEach(LIST, (item: string) => {
          ListItem() {
            VideoModule({ moduleName: item })
              .margin({ top: MARGIN_FONT_SIZE.FIRST_MARGIN })
          }
        }, (item: string) => JSON.stringify(item))
      }
      .listDirection(Axis.Vertical)
      .margin({ top: MARGIN_FONT_SIZE.THIRD_MARGIN })
    }
    ...
  }
}

构建视频播放界面

VideoPlayer.ets其中定义了视频播放子组件VideoPlayer ，onPrepared回调方法中可以获取视频总时长，onUpdate回调方法中可实时获取到视频播放的当前时间戳，onFinish是视频播放结束后的回调方法，onError是视频播放出错的回调方法。

// VideoPlayer.ets
@Component
export struct VideoPlayer {
  private source: string | Resource = '';
  private controller: VideoController = new VideoController();
  private previewUris: Resource = $r('app.media.preview');
  @Provide currentTime: number = 0;
  @Provide durationTime: number = 0;
  @Provide durationStringTime: string = START_TIME;
  @Provide currentStringTime: string = START_TIME;
  @Consume isPlay: boolean;
  @Consume isOpacity: boolean;
  @Consume flag: boolean;
  @Consume isLoading: boolean;
  @Consume progressVal: number;

  build() {
    Column() {
      Video({
        src: this.source,
        previewUri: this.previewUris,
        controller: this.controller
      })
        .width(ALL_PERCENT)
        .height(STRING_PERCENT.NINETY_PERCENT)
        .controls(false)
        .autoPlay(false)
        .objectFit(ImageFit.Contain)
        .loop(false)
        .onUpdate((event) => {
          if (event) {
            this.currentTime = event.time;
            this.currentStringTime = changeSliderTime(this.currentTime);
          }
        })
        .onPrepared((event) => {
          this.prepared(event?.duration);
        })
        .onFinish(() => {
          this.finish();
        })
        .onError(() => {
          prompt.showToast({
            duration: COMMON_NUM_DURATION,
            message: MESSAGE
          });
        })
      VideoSlider({ controller: this.controller })
    }
  }
  ...
}

在自定义组件VideoPlayer底部使用了自定义子组件VideoSlider，VideoSlider自定义组件中显示和控制视频播放进度，效果图如图：

// VideoPlaySlider.ets
@Component
export struct VideoSlider {
  @Consume isOpacity: boolean;
  private controller: VideoController = new VideoController();
  @Consume currentStringTime: string;
  @Consume currentTime: number;
  @Consume durationTime: number;
  @Consume durationStringTime: string;
  @Consume isPlay: boolean;
  @Consume flag: boolean;
  @Consume isLoading: boolean;
  @Consume progressVal: number;

  build() {
    Row({ space: MARGIN_FONT_SIZE.FIRST_MARGIN }) {
      ...
      Slider({
        value: this.currentTime,
        min: 0,
        max: this.durationTime,
        step: 1,
        style: SliderStyle.OutSet
      })
        .blockColor($r('app.color.white'))
        .width(STRING_PERCENT.SLIDER_WITH)
        .trackColor(Color.Gray)
        .selectedColor($r("app.color.white"))
        .showSteps(true)
        .showTips(true)
        .trackThickness(this.isOpacity ? SMALL_TRACK_THICK_NESS : BIG_TRACK_THICK_NESS)
        .onChange((value: number, mode: SliderChangeMode) => {
          this.sliderOnchange(value, mode);
        })
      ...
    }
    .opacity(this.isOpacity ? DEFAULT_OPACITY : 1)
    ...
  }
  ...
}

在VideoController.ets中的视频控制和回调的相关方法。

// VideoControll.ets
export function changeSliderTime(value: number): string {
  let second: number = value % COMMON_NUM_MINUTE;
  let min: number = Number.parseInt((value / COMMON_NUM_MINUTE).toString());
  let head = min < COMMON_NUM_DOUBLE ? `${ZERO_STR}${min}` : min;
  let end = second < COMMON_NUM_DOUBLE ? `${ZERO_STR}${second}` : second;
  let nowTime = `${head}${SPLIT}${end}`;
  return nowTime;
}

在SimpleVideoPlay.ets播放界面，引用VideoPlayer子组件，并在视频播放页面使用堆叠容器，在视频播放画面中心堆叠控制、视频加载图标，效果图如图：

// SimpleVideoPlay.ets
@Entry
@Component
struct Play {
  // 取到Index页面跳转来时携带的source对应的数据。
  private source: string = (router.getParams() as Record<string, Object>).source as string;
  private startIconResource: Resource = $r('app.media.ic_public_play');
  private backIconResource: Resource = $r('app.media.ic_back');
  @Provide isPlay: boolean = false;
  @Provide isOpacity: boolean = false;
  controller: VideoController = new VideoController();
  @Provide isLoading: boolean = false;
  @Provide progressVal: number = 0;
  @Provide flag: boolean = false;

  ...
  onPageHide() {
    this.controller.pause();
  }

  build() {
    Column() {
      // 顶部返回以及标题
　　　　...
      Stack() {
        // 不同的播放状态渲染不同得控制图片
        if (!this.isPlay && !this.isLoading) {
          Image(this.startIconResource)
            .width(MARGIN_FONT_SIZE.FIFTH_MARGIN)
            .height(MARGIN_FONT_SIZE.FIFTH_MARGIN)
            // 同一容器中兄弟组件显示层级关系，z值越大，显示层级越高 用于控制图片在视频上。
            .zIndex(STACK_STYLE.IMAGE_Z_INDEX)
        }
        if (this.isLoading) {
          Progress({
            value: STACK_STYLE.PROGRESS_VALUE,
            total: STACK_STYLE.PROGRESS_TOTAL,
            type: ProgressType.ScaleRing
          })
            .color(Color.Grey)
            .value(this.progressVal)
            .width(STACK_STYLE.PROGRESS_WIDTH)
            .style({
              strokeWidth: STACK_STYLE.PROGRESS_STROKE_WIDTH,
              scaleCount: STACK_STYLE.PROGRESS_SCALE_COUNT,
              scaleWidth: STACK_STYLE.PROGRESS_SCALE_WIDTH
            })
            .zIndex(STACK_STYLE.PROGRESS_Z_INDEX)
        }
        VideoPlayer({
          source: this.source,
          controller: this.controller
        })
          .zIndex(0)
      }
    }
    .height(ALL_PERCENT)
    .backgroundColor(Color.Black)
  }
}