Javascript expo摄像头在react native中未执行takePictureAsync

这就是拍照的功能

import {Camera} from 'expo-camera'

takePicture = async () => {
let camera:Camera;
console.log('shoot fired');
    if (!this.Camera) return
    let photo = await this.Camera.takePictureAsync();
    console.log(photo);
}

启动摄像头功能

startCamera = async () => {
console.log('req camera');
      try {
      
        const granted = await PermissionsAndroid.request(
          PermissionsAndroid.PERMISSIONS.CAMERA,{
            'title': 'Camera required',
            'message': 'This App needs to Access your camera'
          }
        )
        if (granted === PermissionsAndroid.RESULTS.GRANTED) {
          //To Check, If Permission is granted
                     
              
        } else {
          alert("camera Permission Denied");
        }
      } catch (err) {
        //alert("err",err);
        //notifyMessage(err);
        that.setState({status:err});
        
        console.warn(err)
      }
    
} 

然后是渲染部分

let camera: Camera;
<Camera
      style={{flex: 1,width:"100%"}}
      ref={(ref) => {this.camera = ref}}
    ></Camera>

      <TouchableOpacity
        style={buttonStyle('aqua')}
        onPress={this.startCamera}
      >
        <Text>OnCam</Text>
      </TouchableOpacity> 
      
      <TouchableOpacity
        style={buttonStyle('green')}
        onPress={this.takePicture}
      >
        <Text>Shoot</Text>
      </TouchableOpacity>

让摄像机：摄像机；
{this.camera=ref}
>
奥康姆
射击

我已经成功地启动了相机，但当我按下按钮拍摄照片时，它只打印“射击射击”，而没有在缓存目录中生成文件。请帮助我，我想保存图片并重命名它。谢谢