React Native Image Picker：null 不是对象(评估 'ImagePickerManager.showImagePicker')

Question

i根据文档安装了反应本形图像挑战器。当我尝试从手机中选择图像(击中按钮后(时，模拟器给我这个错误 - null is not an object (evaluating 'ImagePickerManager.showImagePicker')

我的React本地版本是0.59.8

和Image Picker的版本为0.28.0

这是代码 -

import React, { Component } from 'react';
import {
  StyleSheet,
  Text,
  View,
  Image,
  Button
} from 'react-native';
import ImagePicker from "react-native-image-picker";
export default class App extends Component {
  state = {
    pickedImage: null
  }
  reset = () => {
    this.setState({
      pickedImage: null
    });
  }


pickImageHandler = () => {
    ImagePicker.showImagePicker({title: "Pick an Image", maxWidth: 800, maxHeight: 600}, res => {
      if (res.didCancel) {
        console.log("User cancelled!");
      } else if (res.error) {
        console.log("Error", res.error);
      } else {
        this.setState({
          pickedImage: { uri: res.uri }
        });
      }
    });
  }

       resetHandler = () =>{
            this.reset();
          }
  render() {
    return (
      <View style={styles.container}>
      <Text style={styles.textStyle}>Pick Image From Camera and Gallery </Text>
        <View style={styles.placeholder}>
          <Image source={this.state.pickedImage} style={styles.previewImage} />
        </View>
        <View style={styles.button}>
          <Button title="Pick Image" onPress={this.pickImageHandler} />
          <Button title="Reset" onPress={this.resetHandler} />
         </View>
      </View>
    );
  }
}

Answer 1

i将图像拾取器的版本降级到28.0.0，然后重建应用程序。现在它正在工作。

Answer 2

我认为当前版本有一个错误。我已经经历了这一点，我所做的就是卸载图像挑选软件包上的当前版本，并安装了版本@1.1.0：

，也可以简单地降级当前版本。

1. npm uninstall react-native-image-picker

2. npm install react-native-image-picker@1.1.0 --save

3. react-native link react-native-image-picker

4. cd ios

5. pod install

6. cd ..

停止并重新运行您的包装器或Bundler

然后重置您的缓存

npm start -reset-cache

Answer 3

不是ImagePickerManager您可以使用ImagePicker

示例

import ImagePicker from 'react-native-image-picker';
// More info on all the options is below in the API Reference... just some common use cases shown here
const options = {
  title: 'Select Avatar',
  customButtons: [{ name: 'fb', title: 'Choose Photo from Facebook' }],
  storageOptions: {
    skipBackup: true,
    path: 'images',
  },
};
/**
 * The first arg is the options object for customization (it can also be null or omitted for default options),
 * The second arg is the callback which sends object: response (more info in the API Reference)
 */
ImagePicker.showImagePicker(options, (response) => {
  console.log('Response = ', response);
  if (response.didCancel) {
    console.log('User cancelled image picker');
  } else if (response.error) {
    console.log('ImagePicker Error: ', response.error);
  } else if (response.customButton) {
    console.log('User tapped custom button: ', response.customButton);
  } else {
    const source = { uri: response.uri };
    // You can also display the image using data:
    // const source = { uri: 'data:image/jpeg;base64,' + response.data };
    this.setState({
      avatarSource: source,
    });
  }
});

Answer 4

在Android Studio中构建项目，如果您遇到一个错误：

this.options.savetophotos＆amp;＆amp;build.version.sdk_int＆lt; = build.version_codes.p＆amp;＆amp;....

在您的 projectName/android/build.gradle 更新这些

   ext {
     buildToolsVersion = "29.0.2"
     minSdkVersion = 21
     compileSdkVersion = 29
     targetSdkVersion = 29
}

，也更新此

  afterEvaluate {
        project -> if (project.hasProperty("android")) {
            android {
                compileSdkVersion 29
                buildToolsVersion '29.0.2'
            }
        }
    }