Question

我正在尝试使用react-native-image-crop-picker。代码如下。我已经尝试过npm install react-native-image-crop-picker @ latest。

每当我选择任何一个选项时，undefined不是一个对象（评估＆＃39; imagePicker.openPicker＆＃39;）。请帮忙解决这个问题。

import React, {Component} from 'react';
import {
View, Text, StyleSheet, ScrollView, Alert,
Image, TouchableOpacity, NativeModules, Dimensions
} from 'react-native';

var ImagePicker = NativeModules.ImageCropPicker;

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center'
  },
  button: {
    backgroundColor: 'blue',
    marginBottom: 10
  },
  text: {
    color: 'white',
    fontSize: 20,
    textAlign: 'center'
  }
});

export default class Upload extends Component {

  constructor() {
    super();
    this.state = {
      image: null,
      images: null
    };
  }

  pickSingleWithCamera(cropping) {
    ImagePicker.openCamera({
      cropping: cropping,
      width: 500,
      height: 500,
    }).then(image => {
      console.log('received image', image);
      this.setState({
        image: {uri: image.path, width: image.width, height: image.height},
        images: null
      });
    }).catch(e => alert(e));
  }

  pickSingleBase64(cropit) {
    ImagePicker.openPicker({
      width: 300,
      height: 300,
      cropping: cropit,
      includeBase64: true
    }).then(image => {
      console.log('received base64 image');
      this.setState({
        image: {uri: `data:${image.mime};base64,`+ image.data, width: image.width, height: image.height},
        images: null
      });
    }).catch(e => alert(e));
  }

  cleanupImages() {
    ImagePicker.clean().then(() => {
      console.log('removed tmp images from tmp directory');
    }).catch(e => {
      alert(e);
    });
  }

  cleanupSingleImage() {
    let image = this.state.image || (this.state.images && this.state.images.length ? this.state.images[0] : null);
    console.log('will cleanup image', image);

    ImagePicker.cleanSingle(image ? image.uri : null).then(() => {
      console.log(`removed tmp image ${image.uri} from tmp directory`);
    }).catch(e => {
      alert(e);
    })
  }

  cropLast() {
    if (!this.state.image) {
      return Alert.alert('No image', 'Before open cropping only, please select image');
    }

    openCropper({
      path: this.state.image.uri,
      width: 200,
      height: 200
    }).then(image => {
      console.log('received cropped image', image);
      this.setState({
        image: {uri: image.path, width: image.width, height: image.height, mime: image.mime},
        images: null
      });
    }).catch(e => {
      console.log(e);
      Alert.alert(e.message ? e.message : e);
    });
  }

  pickSingle(cropit, circular=false) {
    ImagePicker.openPicker({
      width: 300,
      height: 300,
      cropping: cropit,
      cropperCircleOverlay: circular,
      compressImageMaxWidth: 640,
      compressImageMaxHeight: 480,
      compressImageQuality: 0.5,
      compressVideoPreset: 'MediumQuality',
    }).then(image => {
      console.log('received image', image);
      this.setState({
        image: {uri: image.path, width: image.width, height: image.height, mime: image.mime},
        images: null
      });
    }).catch(e => {
      console.log(e);
      Alert.alert(e.message ? e.message : e);
    });
  }

  pickMultiple() {
    ImagePicker.openPicker({
      multiple: true,
      waitAnimationEnd: false
    }).then(images => {
      this.setState({
        image: null,
        images: images.map(i => {
          console.log('received image', i);
          return {uri: i.path, width: i.width, height: i.height, mime: i.mime};
        })
      });
    }).catch(e => alert(e));
  }

  scaledHeight(oldW, oldH, newW) {
    return (oldH / oldW) * newW;
  }

  renderVideo(video) {
    return (<View style={{height: 300, width: 300}}>
      <Video source={{uri: video.uri, type: video.mime}}
         style={{position: 'absolute',
            top: 0,
            left: 0,
            bottom: 0,
            right: 0
          }}
         rate={1}
         paused={false}
         volume={1}
         muted={false}
         resizeMode={'cover'}
         onError={e => console.log(e)}
         onLoad={load => console.log(load)}
         repeat={true} />
     </View>);
  }

  renderImage(image) {
    return <Image style={{width: 300, height: 300, resizeMode: 'contain'}} source={image} />
  }

  renderAsset(image) {
    if (image.mime && image.mime.toLowerCase().indexOf('video/') !== -1) {
      return this.renderVideo(image);
    }

    return this.renderImage(image);
  }

  render() {
    return (<View style={styles.container}>
      <ScrollView>
        {this.state.image ? this.renderAsset(this.state.image) : null}
        {this.state.images ? this.state.images.map(i => <View key={i.uri}>{this.renderAsset(i)}</View>) : null}
      </ScrollView>

      <TouchableOpacity onPress={() => this.pickSingleWithCamera(false)} style={styles.button}>
        <Text style={styles.text}>Select Single With Camera</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={() => this.pickSingleWithCamera(true)} style={styles.button}>
        <Text style={styles.text}>Select Single With Camera With Cropping</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={() => this.pickSingle(false)} style={styles.button}>
        <Text style={styles.text}>Select Single</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={() => this.cropLast()} style={styles.button}>
        <Text style={styles.text}>Crop Last Selected Image</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={() => this.pickSingleBase64(false)} style={styles.button}>
        <Text style={styles.text}>Select Single Returning Base64</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={() => this.pickSingle(true)} style={styles.button}>
        <Text style={styles.text}>Select Single With Cropping</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={() => this.pickSingle(true, true)} style={styles.button}>
        <Text style={styles.text}>Select Single With Circular Cropping</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={this.pickMultiple.bind(this)} style={styles.button}>
        <Text style={styles.text}>Select Multiple</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={this.cleanupImages.bind(this)} style={styles.button}>
        <Text style={styles.text}>Cleanup All Images</Text>
      </TouchableOpacity>
      <TouchableOpacity onPress={this.cleanupSingleImage.bind(this)} style={styles.button}>
        <Text style={styles.text}>Cleanup Single Image</Text>
      </TouchableOpacity>
    </View>
    );
  }
  }

Answer 1

我通过在node_modules中添加一个文件夹react-native-image-crop-picker并运行来摆脱了这个麻烦 cd ios pod install

Answer 2

您是否在标题中导入了该模块？请在代码顶部尝试以下操作：

import ImagePicker from 'react-native-image-crop-picker';

Answer 3

我在大多数函数中也发现，你引用this.setState（）但实际上并没有将你的函数绑定到构造函数中的组件。

尝试在构造函数中添加以下行：

this.pickSingleWithCamera = this.pickSingleWithCamera.bind(this)

如果要传递参数，请以这种方式从组件中调用此函数：

<TouchableOpacity onPress={() => this.pickSingleWithCamera.bind(this, false)} style={styles.button}>
  <Text style={styles.text}>Select Single With Camera</Text>
</TouchableOpacity>

这仅适用于您的某项功能，您需要为其他人执行此操作。这可能会起作用，我不是百分百肯定。

未定义不是对象（评估＆＃39; imagePicker.openPicker＆＃39;）

3 个答案: