可能未处理的承诺拒绝

Question

我正在尝试使用 mobilenet 对图像进行分类。我收到此错误：

<块引用>

可能的未处理的承诺拒绝（id：16）： 类型错误：网络请求失败 http://localhost:8081/node_modules/@tensorflow/tfjs-react-native/dist/platform_react_native.bundle?platform=ios&dev=true&minify=false&modulesOnly=true&runModule=false&shallow=true:85:44

这是源代码：

import * as tf from '@tensorflow/tfjs';
import '@tensorflow/tfjs-react-native';
import * as tf from '@tensorflow/tfjs';
import '@tensorflow/tfjs-react-native';
import * as mobilenet from '@tensorflow-models/mobilenet';
import { fetch, decodeJpeg } from '@tensorflow/tfjs-react-native';


import React from 'react';
import { 
    SafeAreaView,
    View, 
    Text,
    TextInput,
    StyleSheet,
    TouchableOpacity,
    Image,
    Button,
    ScrollView,
    FlatList, 
    Touchable} from 'react-native';
    import { icons, images, SIZES, COLORS, FONTS } from '../constants';

    



const Trip = () => {


    const [url, seturl]= React.useState(images.shark)
    const [displayText, setDisplayText] = React.useState('loading')

    async function getPrediction(url){
        setDisplayText("Loading Tensor Flow")
        await tf.ready()
        setDisplayText("Loading Mobile Net")
        const model= await mobilenet.load()
        setDisplayText("Fetching image")
        const response =await fetch(url, {}, {isBinary: true})
        setDisplayText("Getting image buffer")
        const imageData = await response.arrayBuffer() 
        setDisplayText("Getting Image tensor")
        const imageTensor = imageToTensor(imageData)
        setDisplayText("Loading Result")
        const prediction = await model.classify(imageTensor)
        setDisplayText(JSON.stringify(prediction))

    }



    function imageToTensor(rawData){
        const {width, height, data}= jpeg.decode(rawData, true)
        const buffer = new Uint8Array(width*height*3)
        let offset = 0;
        for(let i=0; i<buffer.length; i+=3){
            buffer[i]=data[offset]
            buffer[i+1]=data[offset+1]
            buffer[i+2]=data[offset+2]
            buffer +=4

        }

        return tf.tensor3d(buffer, [height,width,3])

    }

function renderHeader(){
    return(

        <View style={{ flexDirection: 'row', height: 50 }}>
            <TouchableOpacity
                style={{
                    width: 50,
                    paddingLeft: SIZES.padding * 2,
                    justifyContent: 'center',
            
                }}
                onPress={()=> navigation.navigate("Explore")}
            
                >
                
                </TouchableOpacity>
                <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
                    <View
                    style={{
                        width: '80%',
                        height: "100%",
                        alignItems: 'center',
                        justifyContent: 'center',
                        borderRadius: SIZES.radius
                    }}>
                <Text  style={{ ...FONTS.h3 }}> COVID-PNEUMONIA  </Text>
                
                    </View>
                </View>

                <TouchableOpacity
                style={{
                    width: 50,
                    paddingLeft: SIZES.padding/2,
                    justifyContent: 'center'
                }}
                >
                
                    </TouchableOpacity>
    </View>
    )
}


function BackDrop(){
    return(
        <View style={{height: 200}}>
            <TouchableOpacity
            style={{
                width: '100%',
                paddingLeft: SIZES.padding * 4,
                paddingTop: SIZES.padding*10,
        
                justifyContent: 'center',
        
            }}>
                <Text>Check Dog or Cat?</Text>
            <TextInput style={{height:40, width:"90%", borderColor:'gray', borderWidth: 1}}
            value={url}/>
{/* 
            <Image
                source={images.visitnepal2020}
                resizeMode="contain"
                style={{
                    width: '100%',
                    height: '100%'
                }}
            /> */}
                <Image style={styles.imageStyle} source={url}></Image>

<Button title="Classify" color="#841584" onPress={()=>getPrediction(url)}  style={styles.buttonStyle} ></Button>

            </TouchableOpacity>
        </View>
    )
}



    return (
        <SafeAreaView style={{flex:1}, styles.container} >
            {renderHeader()}
            {BackDrop()}
            {/* <Text>Works with only JPEG Images</Text>
            <TextInput style={{height:40, width:"90%", borderColor:'gray', borderWidth: 1}}
            value={url}/>
            <Image source={{url:url}}></Image>
            <Button title="Classify" onPress={()=>getPrediction(url)}></Button> */}

        
        </SafeAreaView>
    )
}

const styles = StyleSheet.create({
    container: {
        flex: 1,
        backgroundColor: COLORS.lightGray4
    },
    shadow: {
        shadowColor: "#000",
        shadowOffset: {
            width: 0,
            height: 3,
        },
        shadowOpacity: 0.1,
        shadowRadius: 3,
        elevation: 1,
    },buttonStyle: {
        color: 'red',
        marginTop: 20,
        padding: 20,
        backgroundColor: 'green'
    },
    imageStyle:{
        width: 350,
        height: 200
    }
})



export default Trip;