React native 如何压缩刚用React Native Expo拍摄的照片
我正在使用expo和MediaLibrary的摄像头组件保存拍摄的照片。我的问题是,在Galery中使用MediaLibrary保存图像时,如何压缩该图像?我正在尝试压缩它,因为稍后我还会将该图像上载到Firebase存储。到目前为止,这是我现在没有压缩的代码:React native 如何压缩刚用React Native Expo拍摄的照片,react-native,camera,compression,expo,media-library,React Native,Camera,Compression,Expo,Media Library,我正在使用expo和MediaLibrary的摄像头组件保存拍摄的照片。我的问题是,在Galery中使用MediaLibrary保存图像时,如何压缩该图像?我正在尝试压缩它,因为稍后我还会将该图像上载到Firebase存储。到目前为止,这是我现在没有压缩的代码: import React, { useState, useEffect} from 'react'; import { Text, View, TouchableOpacity } from 'react-native'; import
import React, { useState, useEffect} from 'react';
import { Text, View, TouchableOpacity } from 'react-native';
import { Camera } from 'expo-camera';
import * as MediaLibrary from 'expo-media-library';
import { Dimensions } from 'react-native';
const {height, width} = Dimensions.get('window');
export default function App() {
const [hasPermission, setHasPermission] = useState(null);
const [cameraRef, setCameraRef] = useState(null)
const [type, setType] = useState(Camera.Constants.Type.back);
useEffect(() => {
(async () => {
const { status } = await Camera.requestPermissionsAsync();
MediaLibrary.requestPermissionsAsync();
setHasPermission(status === 'granted');
})();
}, []);
if (hasPermission === null) {
return <View />;
}
if (hasPermission === false) {
return <Text>No access to camera</Text>;
}
return (
<View style={{ flex: 1 }}>
<Camera style={{ flex: 1 }} type={type} ref={ref => {
setCameraRef(ref) ;
}}>
<View
style={{
flex: 1,
backgroundColor: 'transparent',
justifyContent: 'flex-end'
}}>
<TouchableOpacity style={{alignSelf: 'center', marginBottom: 20}} onPress={async() => {
if(cameraRef){
let photo = await cameraRef.takePictureAsync({ skipProcessing: true });
MediaLibrary.saveToLibraryAsync(photo.uri);
}
}}>
<View style={{
borderWidth: 2,
borderColor: 'white',
height: 50,
width:50,
display: 'flex',
justifyContent: 'center',
alignItems: 'center',
borderRadius: 25,
}}
>
<View style={{
borderWidth: 2,
borderColor: 'white',
height: 40,
width:40,
backgroundColor: 'white',
borderRadius: 25}} >
</View>
</View>
</TouchableOpacity>
</View>
</Camera>
</View>
);
}
ImageManipular随expo提供,您可以压缩、调整大小、旋转、裁剪等
签出图像操纵器随expo附带,您可以压缩、调整大小、旋转、裁剪以及更多操作
签出图像操纵器已移动到程序包。更新您的示例:
从“React”导入React,{useState,useffect};
从“react native”导入{Text,View,TouchableOpacity};
从“expo Camera”导入{Camera};
从“世博媒体库”导入*作为媒体库;
从“react native”导入{Dimensions};
//新进口
从“expo图像操纵器”导入*作为图像操纵器;
const{height,width}=Dimensions.get'window';
导出默认功能应用程序{
//和以前一样的代码
回来
{
setCameraRef;
}}>
{
ifcameraRef{
let photo=wait cameraRef.takePictureAsync{skipping processing:true};
//这里有新代码
const manippresult=wait ImageManipulator.manipleAsync
photo.uri,
[{rotate:90},{flip:ImageManipulator.FlipType.Vertical}],
{压缩:1,格式:ImageManipulator.SaveFormat.PNG}
;
MediaLibrary.SaveToLibrary AsynchManipResult.uri;
}
}}>
;
}
.图像操纵器已移动到程序包。更新您的示例:
从“React”导入React,{useState,useffect};
从“react native”导入{Text,View,TouchableOpacity};
从“expo Camera”导入{Camera};
从“世博媒体库”导入*作为媒体库;
从“react native”导入{Dimensions};
//新进口
从“expo图像操纵器”导入*作为图像操纵器;
const{height,width}=Dimensions.get'window';
导出默认功能应用程序{
//和以前一样的代码
回来
{
setCameraRef;
}}>
{
ifcameraRef{
let photo=wait cameraRef.takePictureAsync{skipping processing:true};
//这里有新代码
const manippresult=wait ImageManipulator.manipleAsync
photo.uri,
[{rotate:90},{flip:ImageManipulator.FlipType.Vertical}],
{压缩:1,格式:ImageManipulator.SaveFormat.PNG}
;
MediaLibrary.SaveToLibrary AsynchManipResult.uri;
}
}}>
;
}
import { ImageManipulator } from 'expo';
const manipResult = await ImageManipulator.manipulate(
imageUri,
[{ resize: { width: 640, height: 480 } }],
{ format: 'jpg' }
);