Javascript 等待映射内的所有异步函数完成执行

我想完成映射中所有异步函数的执行，然后更改组件的状态。我给你留了一部分代码，以备你能帮我

我只是想在每次用户取消时显示我自己的权限屏幕

简单来说，我有以下几点：

const permissions = {
    cameraRoll: {
        iconType: "ionicon",
        iconName: "ios-images",
        title: "Enable camera roll",
        subtitle:
          "To upload content from your Gallery, you have to granted the camera roll permission",
        buttonText: "Enable camera roll",
        checkPermission: checkCameraRollPermission,
        requirePermission: requireCameraRollPermission,
      },
    };
}


const checkCameraRollPermission = async () => {
    const { status, canAskAgain } = await Permissions.getAsync(
      Permissions.CAMERA_ROLL
    );
    return { status, canAskAgain };
  };


  const requireCameraRollPermission = async () => {
    const { status, canAskAgain } = await Permissions.askAsync(
      Permissions.CAMERA_ROLL
    );
    return { status, canAskAgain };
  };


/* I HAVE TO WAIT FOR ALL THE FUNCTIONS TO FINISH EXECUTION
FOR EACH OBJECT ON THE MAP BUT THIS IS NOT WORKING :( */
getMissingPermissions = () => {
    // Only check permissions on the foreground
    if (AppState.currentState.match(/active/)) {
      // We have to empty the current missing permssions and recalculate them
      const permissionsArray = [];
      Promise.all(
        Object.keys(permissions).map((key) => {
          permissions[key].checkPermission().then(({ status }) => {
            if (status !== "granted") {
              permissionsArray.push(permissions[key]);
            }
          });
        })
      ).then(() => {

        this.setState({
          missingPermissions: permissionsArray,
        });
      });
    }
  };

---

有什么想法吗？感谢与

承诺。您需要以数组形式提供承诺。目前，您没有从地图中返回导致问题的任何内容

也可以不使用permissionsArray变量，只需从嵌套的promise中返回所需的值，该值将在
promise.all（…）。然后（…）
响应中可用

getMissingPermissions = () => {
    // Only check permissions on the foreground
    if (AppState.currentState.match(/active/)) {
      // We have to empty the current missing permssions and recalculate them
      Promise.all(
        Object.keys(permissions).map((key) => {
          return permissions[key].checkPermission().then(({ status }) => {
            if (status !== "granted") {
              return permissions[key];
            }
            return;
          });
        })
      ).then((res) => {
        const permissionsArray = res.filter(Boolean)// Filter out undefined values
        this.setState({
          missingPermissions: permissionsArray,
        });
      });
    }
  };

.map（）
的回调应该
返回一个值现在您的
权限
对象只有一个请求的权限。它最终会有不止一个吗？如果没有，那么你甚至不需要映射权限调用。是的，它有更多，它被简化了