小编Oja*_*jay的帖子

因此，我使用 ScrollView 在 React Native 中手动创建了一个入门屏幕，并且还添加了一个标记为 next 的按钮，以使隐藏屏幕能够移入屏幕上。现在我的挑战是如何在按下按钮时以编程方式使 ScrollView 滚动。下面是我尝试过的示例功能组件，但我不知道如何实现按钮按下滚动

export default function Onbaording({ navigation }) {
  const [sliderState, setSliderState] = React.useState({ currentPage: 0 });
  const { width, height } = Dimensions.get("window");

  const setSliderPage = (event) => {
    const { currentPage } = sliderState;
    const { x } = event.nativeEvent.contentOffset;
    const indexOfNextScreen = Math.floor(x / width);
    if (indexOfNextScreen !== currentPage) {
      setSliderState({
        ...sliderState,
        currentPage: indexOfNextScreen,
      });
    }
  };

  const { currentPage: pageIndex } = sliderState;

  return (
    <View style={Styles.container}>
      <SafeAreaView …

我从Google Material.io下载了一个图标。在集成后尝试构建我的项目时，我遇到了一个错误：Can't process attribute android:fillColor="@android:color/white"

这是屏幕截图：

我正在使用twitter bootstrap的模态制作弹出表单。

这是下面的代码，显示了模式形式。

第一模态形式

<div class="modal fade" id="myModal" role="dialog">
    <div class="modal-dialog modal-dialog1">

      <!-- Modal content-->
      <div class="modal-container">

        <div class="modal-header" id="header-modal">
          <button type="button" class="close-modal" data-dismiss="modal">&times;</button>
          <h4 class="modal-h2">Modal Header</h4>
        </div>

        <div class="modal-body">

          <div class="row">
            <div class="col-md-12">
                <h2 id="modal-info-header">Student's Information</h2>
            </div>  
          </div>

            <div class="row">
              <div class="col-md-12">
                <form role="form">

                  <div class="row">
                    <div class="col-md-6">
                      <div class="modal-form-col1">
                        <label for="guidiantName">First Name</label> <br>
                        <input type="text" class="modal-form-input" id="" name="guidiantName" placeholder="First Name">
                      </div>
                    </div>

                     <div class="col-md-6">
                      <div class="modal-form-col2">
                        <label for="guidiantName">Last Name</label> <br>
                        <input type="text" class="modal-form-input" id="" name="guidiantName" placeholder="Last Name">
                      </div> …

我需要通过从搜索组件到 userList 组件的路由传递 queryParams 来实现“搜索”（例如。/search-result?user="Alfred"）。在加载 userList 组件之前，我需要使用 userList 解析器中的 queryParams 进行 API 调用，但查询参数一直显示未定义。

搜索组件

search(searchTerm: string) {
    if (searchTerm) {
      this.router.navigate(['search-result'], { queryParams: { user: searchTerm } });
  }
}

用户列表解析器

export class UserResolver implements Resolve<User[]> {
  constructor(private userService: UserService, private route: ActivatedRoute) { }

  resolve(): Observable<User[]> {
    const searchTerm: string = this.route.snapshot.queryParams['user'];
    console.log(searchTerm); //Logs Undefined

    return this.userService.getUsers(searchTerm);
  }
}

After searching to center my div all I could get was margin: 0 auto; together with an assigned width, but still it not working.

My problem is simply centering a div. I have no idea why margin: 0 auto; isn't working.

Here is the layout of my CSS/html:

CSS

    .countdown-box {
       position: absolute;
       width: 80px;
       margin: 0 auto;
       height: 130px;
       /*left: 50%;*/
       background: #008040;
       border-radius: 4px;
       z-index: 2;
    }

<div class="countdown-box"></div>