Brooke  Giles

Brooke Giles

1560311265

Export or Import of CSV or Excel file in Laravel 5.8 with MySQL

In this article, I will give you very simple step by step tutorial of import csv or excel file and export csv or excel file using maatwebsite/excel version 3 in Laravel 5.8 application.

Do you know Import or Export CSV or Excel sheet data from MySQL Database is a primary needs of any admin level project. For this here we have make simple tutorial, in which we have step by step describe how to import CSV or Excel sheet data and Export CSV File or Excel sheet data in Laravel 5.8 application by using maatwebsite/excel version 3 package. There are many changes has been done in maatwebsite version 3 package. So, you have to need to know how to Export or Import of CSV or Excel file data in Laravel 5.8 with Mysql Database. This updated package is now very simple and easy way to use with Laravel latest version like 5.7 and 5.8 for import excel CSV file data from Mysql database.

Suppose We have to some time export or import thousand of records import or export from our database. Then Maatwebsite has been offer functionality for importing and exporting of large records in CSV file or Excel sheet. For learn this feature here we will make import data in CSV file and import into mysql in laravel 5.8 application. For this task here we will use maatwebsite/excel package for importing and exporting data task with laravel 5.8 framework. Because maatwebsite/excel package has provide very easy method for import and export data using database model. Below you can find step by step process for how to use maatwebsite/excel version for import and export csv file data in Laravel 5.8 application.

Export or Import of CSV or Excel file in Laravel 5.8 with MySQL

Table Content

  • Install Laravel 5.8 framework
  • Add Fake Records in Mysql Database
  • Install Maatwebsite Package
  • Create Import Class
  • Create Export Class
  • Create Controller
  • Create Blade View File
  • Add route

Install Laravel 5.8 framework

First We need to download Laravel 5.8 version, and install into our computer. For this we have to go command prompt, in which we have to already run composer command and write following command. It will download Laravel 5.8 version in define folder.

 composer create-project --prefer-dist laravel/laravel csv_file 

After installing Laravel 5.8 framwork, after this we need to make database connection. For this we have to open .env file and under this file we have to define Mysql database configuration details which you can see below.

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=testing
DB_USERNAME=root
DB_PASSWORD=

After makiing database configuration, now in next step we will see how to make table from Laravel 5.8 application.

Add Fake Records in Mysql Database

For add fake record into Mysql database. First we want to make table in Mysql database from this Laravel 5.8 application. Here we will use user default model for migrate data from this Laravel 5.8 application. If you have download fresh Laravel 5.8 framework, then you can find User default model in app/User.php. And for migrate data, you have to go command prompt and write following command.

php artisan migrate 

This command will migrate default data from database/migrations folder and it will make user table in define Mysql database. Now for add fake records, we have to write following command in command prompt.

php artisan tinker

factory(App\User::class, 20)->create();

This command will add 20 fake records in User table, so we can perform import export data operation with CSV file.

Install Maatwebsite Package

Now for import and export data to csv file, we need to download and install Maatwebsite Version 3.0 package, for this we have go to command prompt and write following command.

composer require maatwebsite/excel 

This command will download maatwebsite package in Laravel 5.8 application. Now we want to add into Laravel 5.8 application. For this we have open config/app.php and following service provider and aliase.

config/app.php

'providers' => [

 ....

 Maatwebsite\Excel\ExcelServiceProvider::class,

],

'aliases' => [

 ....

 'Excel' => Maatwebsite\Excel\Facades\Excel::class,

],

So, this way we can add maatwebsite/excel package in Laravel 5.8 application.

Create Import Class

Now we want to create import class for import data using maatwebsite 3.0 package in Laravel 5.8 frameworl. For this we have to write following command in command prompt.

php artisan make:import CsvImport --model=User 

This command will make CsvImport.php import class under Import. We have to open this class and under this we to define table column which data we want to get from CSV file. Below you can find complete source code of Import Class for import data from CSV file by using Maatwebsite/excel 3.0 package in Laravel 5.8.

Imports/CsvImport.php

<?php

namespace App\Imports;

use App\User;
use Maatwebsite\Excel\Concerns\ToModel;
use Maatwebsite\Excel\Concerns\WithHeadingRow;

class CsvImport implements ToModel, WithHeadingRow
{
    /**
    * @param array $row
    *
    * @return \Illuminate\Database\Eloquent\Model|null
    */
    public function model(array $row)
    {
        return new User([
            'name'      =>  $row["name"],
            'email'     =>  $row["email"],
            'password'  =>  \Hash::make($row['password']),
        ]);
    }
}

Create Export Class

After this for export mysql data into CSV file or excel sheet, we need to create Export class of maatwebsite using Laravel model. For this we have to write following command in command prompt.

php artisan make:export CsvExport --model=User 

This command will make CsvExport.php class under Exports folder. You can find source code of this class below. We need to add this class into controller header for export data into CSV or Excel file.

Exports/CsvExport.php

<?php

namespace App\Exports;

use App\User;
use Maatwebsite\Excel\Concerns\FromCollection;

class CsvExport implements FromCollection
{
    /**
    * @return \Illuminate\Support\Collection
    */
    public function collection()
    {
        return User::all();
    }
}

Create Controller

Now we have to create controller for handle http request for import and export data. For this we have to write following command in command prompt.

php artisan make:controller CsvFile 

This command will create controller under app/Http/Controllers/CsvFile.php file. In this file first we need to add import class, export class, maatwebsite and User model class. In this controller we have make following method.

index() - This method has load all data of user data with pagination feature.

csv_export() - This method has been received data export to csv file request. This method will export all User table data into CSV file format using CsvExport class and CSV file download in computer.

csv_import() - This method has been used for import csv file data into Mysql database. This method has import data from csv file by using CsvImport class.

Create Blade View File

For display output in browser, we have to create blade file for display Laravel 5.8 application output on browser. You can find below two blade file has been used for display output on web page.

resources/views/csv_file.blade.php



 
  
  Laravel 5.8 - Import Export Data in CSV File
  
  
  
 
 
      
     

     ### Laravel 5.8 - Import Export Data in CSV File

     

     
          
           ### Laravel 5.8 - Import Export Data in CSV File

          
          
           
            @csrf
            
                  

                  Import User Data
                  [Export User Data]({{ route('export') }} "Export User Data")
           
              @yield('csv_data')
          
      
  
 



resources/views/csv_file_pagination.blade.php

@extends('csv_file')

@section('csv_data')


 
  
   Name
   Email Address
  
 
 
 @foreach($data as $row)
  
   {{ $row->name }}
   {{ $row->email }}
  
 @endforeach
 


{!! $data->links() !!}

@endsection

Add route

Lastly we need to add route for import and export operation. For this we have to open routes/web.php file. In this file you can define below route for import and export method.

Route::get('csv_file', 'CsvFile@index');

Route::get('csv_file/export', 'CsvFile@csv_export')->name('export');

Route::post('csv_file/import', 'CsvFile@csv_import')->name('import');

Now we are ready for import and export data into CSV file in Laravel 5.8 by using maatwebsite 3.0 version. For this first we want to start Laravel 5.8 server, for this we have to write following command in command prompt.

php artisan serve 

This command will start Laravel server and give you base url of Laravel application. For test import and export data operation we have to write following url in browser.

http://localhost:8000/csv_file


Now you can check your Laravel 5.8 import export data into CSV file. We hope it will help you to learn Laravel 5.8 with maatwebsite package.

#laravel #php

What is GEEK

Buddha Community

Export or Import of CSV or Excel file in Laravel 5.8 with MySQL

Laravel 8 Import Export CSV/EXCEL File Example

In this post i will show you Laravel 8 Import Export CSV/EXCEL File Example. We will simple create import data to xls, csv file and also we will import data to database using csv file in laravel 8 application.

Using this example we can easily import-export and download the csv & excel file from the database using the maatwebsite/excel composer package. maatwebsite/excel provide easy way to import and export csv file in laravel 8 using database model.

Laravel 8 Import Export CSV/EXCEL File Example

https://websolutionstuff.com/post/laravel-8-import-export-csv-excel-file-example

#laravel 8 import export csv/excel file example #laravel 8 #import #export #csv/excel #import and export csv file in laravel 8

Léon  Peltier

Léon Peltier

1656979200

Comment Exporter Une Fonction De C++ Vers React Native

Aujourd'hui, je continue à partager mon expérience avec le module natif et C++.

Comme nous verrons beaucoup de bibliothèques C/C++ écrire pour les plates-formes mobiles, nous devons les implémenter dans notre application iOS ou React Native. C'est pourquoi je souhaite écrire un article sur la façon d'exporter une fonction de C++ vers React Native, ce qui est facile à comprendre et fait gagner du temps aux débutants. Je vais commencer avec une nouvelle application native réactive

1. Créez une nouvelle application native React, ouvrez votre terminal et exécutez

npx react-native init NativeModules

2. Ouvrez Xcode et accédez à NativeModules/ios/NativeModule.xcworkspace

3. Travailler du côté C++

Créez un nouveau fichier C++ et nommez-leCpp_to_RN.cpp

Lorsque nous créons un nouveau fichier C++, Xcode créera un fichier d'en-tête Cpp_to_RN.hpp pour nous

Tout d'abord, ouvrez le fichier " Cpp_to_RN.hpp" et créez une classe qui inclut une fonction sans le corps.

#ifndef Cpp_to_RN_hpp
#define Cpp_to_RN_hpp#include <stdio.h>
#include <string>class Cpp_to_RN {
public:
    std::string sayHello();
};#endif /* Cpp_to_RN_hpp */

Ouvrez ensuite le Cpp_to_RN.cppfichier et écrivez une fonction simple " sayHello()"

#include "Cpp_to_RN.hpp"
std::string Cpp_to_RN::sayHello(){
    return "Hello from CPP";
}

4. Travail sur l'encapsulation du fichier C++.

Pour envelopper les fichiers C++ et les exporter vers le côté IOS (swift)

un. Créez un fichier Objective C et nommez-leCpp_to_RN.m

Renommez le Cpp_to_RN.m en Cpp_to_RN.mm

b. Ouvrez le WrapCpp_to_RN.mm fichier et écrivez le contenu du corps qui encapsulera la fonction sayHelloà partir du fichier C++.

#import <Foundation/Foundation.h>
#import "WrapCpp_to_RN.h"
#import "Cpp_to_RN.hpp"@implementation WrapCpp_to_RN- (NSString *) sayHello {
  Cpp_to_RN fromCPP;
    std::string helloWorldMessage = fromCPP.sayHello();
    return [NSString
            stringWithCString:helloWorldMessage.c_str()
            encoding:NSUTF8StringEncoding];
}
@end

c. Créez un fichier d'en-tête et nommez-leWrapCpp_to_RN.h

Exporter la wrapSayHellofonction vers le fichier Swift

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

5. Travailler du côté iOS (Swift)

Pour exporter la fonction C++ vers React Native

un. Créez un fichier Swift et nommez-leSendCpp_to_RN.swift

Remarque : Xcode nous demandera de créer un NativeModules-Bridging-Header.hfichier pour nous.

Créez une classe SendCpp_to_RNet déclarez-la commeNSObject

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

Écrire une fonction requiresMainQueueSetup()pour empêcher l'avertissement lorsque nous exécutons l'application

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

Ecrire une fonction pour envelopper le WrapCpp_to_RN()fromWrapCpp_to_RN.mm

import Foundation@objc(SendCpp_to_RN)
class SendCpp_to_RN : NSObject {
    
  @objc static func requiresMainQueueSetup() -> Bool {
        return false
    }
  
  @objc func fromCpp(_ successCallback: RCTResponseSenderBlock) -> Void {
    successCallback([NSNull(), WrapCpp_to_RN().wrapSayHello() as Any])
    }}

b. Exporter une fonction wrap dans un fichier Swift vers React Native

Créez un fichier Objective C pour exporter la classe Swift et sa fonction à l'aide deCallback

#import <React/RCTBridgeModule.h>
#import <Foundation/Foundation.h>
#import "UIKit/UIKit.h"
@interface RCT_EXTERN_MODULE(SendCpp_to_RN, NSObject)RCT_EXTERN_METHOD(fromCpp:(RCTResponseSenderBlock)successCallback)@end

c. Connectez Swift à React Native, ouvrez le NativeModules-Bridging-Header.h fichier

#import <React/RCTBridgeModule.h>#import <React/RCTViewManager.h>#import "WrapCpp_to_RN.h"

6. Travailler du côté React Native

Appelez la classe Swift et ses fonctions

import React from 'react';
import {StyleSheet, Text, View, NativeModules, Button} from 'react-native';const App = () => {
  const onPress = () => {
    const {SendCpp_to_RN} = NativeModules;
    SendCpp_to_RN.fromCpp((_err, res) => console.log(res));
  };
  return (
    <View style={styles.container}>
      <Text> Practice !</Text>
      <Button title="C++ to React Native" color="#841584" onPress={onPress} />
    </View>
  );
};
const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
});
export default App;

Et nous avons terminé, il suffit de lancer l'application

react-native run-ios

Ou cliquez simplement sur le bouton "exécuter" sur Xcode et voyez ce que nous avons fait.

J'espère que mon article vous sera utile, merci pour le temps de lecture.

 Source : https://betterprogramming.pub/native-modules-export-c-function-to-react-native-for-beginners-77e89934b210

#cpp #cplusplus #react 

Hoang  Ha

Hoang Ha

1656981000

Cách Xuất Một Hàm Từ C ++ Sang React Native

Hôm nay, tôi tiếp tục chia sẻ kinh nghiệm của mình với Native Module và C ++.

Vì chúng ta sẽ thấy rất nhiều thư viện C / C ++ viết cho nền tảng di động, chúng ta cần triển khai chúng cho ứng dụng iOS hoặc React Native của mình. Đó là lý do mình muốn viết một bài hướng dẫn cách export một hàm từ C ++ sang React Native dễ hiểu và tiết kiệm thời gian cho người mới bắt đầu. Tôi sẽ bắt đầu với một ứng dụng gốc phản ứng mới

1. Tạo một ứng dụng gốc phản ứng mới, mở thiết bị đầu cuối của bạn và chạy

npx react-native init NativeModules

2. Mở Xcode và điều hướng đến NativeModules / ios / NativeModule.xcworkspace

3. Làm việc trên C ++

Tạo một tệp C ++ mới và đặt tên cho nóCpp_to_RN.cpp

Khi chúng tôi tạo tệp C ++ mới, Xcode sẽ tạo tệp tiêu đề Cpp_to_RN.hpp cho chúng tôi

Đầu tiên, mở tệp Cpp_to_RN.hpp“” và tạo một lớp bao gồm một hàm không có phần thân.

#ifndef Cpp_to_RN_hpp
#define Cpp_to_RN_hpp#include <stdio.h>
#include <string>class Cpp_to_RN {
public:
    std::string sayHello();
};#endif /* Cpp_to_RN_hpp */

Sau đó, mở Cpp_to_RN.cpptệp và viết một hàm đơn giản “ sayHello()

#include "Cpp_to_RN.hpp"
std::string Cpp_to_RN::sayHello(){
    return "Hello from CPP";
}

4. Thao tác trên Wrapping C ++ file.

Để bọc các tệp C ++ và xuất chúng sang phía IOS (nhanh chóng)

một. Tạo một tệp Objective C và đặt tên cho nóCpp_to_RN.m

Đổi tên Cpp_to_RN.m thành Cpp_to_RN.mm

b. Mở WrapCpp_to_RN.mm tệp và viết nội dung phần nội dung sẽ bọc hàm sayHellotừ tệp C ++.

#import <Foundation/Foundation.h>
#import "WrapCpp_to_RN.h"
#import "Cpp_to_RN.hpp"@implementation WrapCpp_to_RN- (NSString *) sayHello {
  Cpp_to_RN fromCPP;
    std::string helloWorldMessage = fromCPP.sayHello();
    return [NSString
            stringWithCString:helloWorldMessage.c_str()
            encoding:NSUTF8StringEncoding];
}
@end

c. Tạo một tệp tiêu đề và đặt tên cho nóWrapCpp_to_RN.h

Xuất wrapSayHellohàm sang tệp Swift

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

5. Làm việc trên iOS (Swift)

Để xuất hàm C ++ sang React Native

một. Tạo một tệp Swift và đặt tên cho nóSendCpp_to_RN.swift

Lưu ý: Xcode sẽ yêu cầu chúng tôi tạo một NativeModules-Bridging-Header.htệp cho chúng tôi.

Tạo một lớp SendCpp_to_RNvà khai báo nó làNSObject

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

Viết một hàm requiresMainQueueSetup()để ngăn cảnh báo khi chúng tôi chạy ứng dụng

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

Viết một hàm để bọc WrapCpp_to_RN()từWrapCpp_to_RN.mm

import Foundation@objc(SendCpp_to_RN)
class SendCpp_to_RN : NSObject {
    
  @objc static func requiresMainQueueSetup() -> Bool {
        return false
    }
  
  @objc func fromCpp(_ successCallback: RCTResponseSenderBlock) -> Void {
    successCallback([NSNull(), WrapCpp_to_RN().wrapSayHello() as Any])
    }}

b. Xuất một hàm bọc trong tệp Swift sang React Native

Tạo một tệp Objective C để xuất lớp Swift và chức năng của nó bằng cách sử dụngCallback

#import <React/RCTBridgeModule.h>
#import <Foundation/Foundation.h>
#import "UIKit/UIKit.h"
@interface RCT_EXTERN_MODULE(SendCpp_to_RN, NSObject)RCT_EXTERN_METHOD(fromCpp:(RCTResponseSenderBlock)successCallback)@end

c. Kết nối Swift với React Native, mở NativeModules-Bridging-Header.h tệp

#import <React/RCTBridgeModule.h>#import <React/RCTViewManager.h>#import "WrapCpp_to_RN.h"

6. Làm việc ở phía React Native

Gọi lớp Swift và các chức năng của nó

import React from 'react';
import {StyleSheet, Text, View, NativeModules, Button} from 'react-native';const App = () => {
  const onPress = () => {
    const {SendCpp_to_RN} = NativeModules;
    SendCpp_to_RN.fromCpp((_err, res) => console.log(res));
  };
  return (
    <View style={styles.container}>
      <Text> Practice !</Text>
      <Button title="C++ to React Native" color="#841584" onPress={onPress} />
    </View>
  );
};
const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
});
export default App;

Và chúng tôi đã hoàn tất, chỉ cần chạy ứng dụng

react-native run-ios

Hoặc chỉ cần nhấp vào nút “chạy” trên Xcode và xem những gì chúng tôi đã làm.

Tôi hy vọng bài viết của tôi hữu ích cho bạn, cảm ơn bạn đã dành thời gian đọc.

 Nguồn: https://betterprogramming.pub/native-modules-export-c- Chức năng-to-react-native-for-beginners-77e89934b210

#cpp #cplusplus #react 

坂本  篤司

坂本 篤司

1656981060

関数をC++からReactNativeにエクスポートする方法

今日も、ネイティブモジュールとC++での経験を共有し続けています。

多くのC/C ++ライブラリがモバイルプラットフォーム用に作成されているので、それらをiOSまたはReactNativeアプリケーションに実装する必要があります。そのため、関数をC++からReactNativeにエクスポートする方法についての記事を書きたいと思います。これは、理解しやすく、初心者の時間を節約できます。新しいreactネイティブアプリケーションから始めます

1.新しいreactネイティブアプリを作成し、ターミナルを開いて実行します

npx react-native init NativeModules

2. Xcodeを開き、NativeModules / ios/NativeModule.xcworkspaceに移動します

3.C++側での作業

新しいC++ファイルを作成し、名前を付けますCpp_to_RN.cpp

新しいC++ファイルを作成すると、XcodeはヘッダーファイルCpp_to_RN.hpp を作成します

まず、「Cpp_to_RN.hppファイルを開き、本体のない関数を含むクラスを作成します。

#ifndef Cpp_to_RN_hpp
#define Cpp_to_RN_hpp#include <stdio.h>
#include <string>class Cpp_to_RN {
public:
    std::string sayHello();
};#endif /* Cpp_to_RN_hpp */

次に、ファイルを開いてCpp_to_RN.cpp、単純な関数「sayHello()」を記述します。

#include "Cpp_to_RN.hpp"
std::string Cpp_to_RN::sayHello(){
    return "Hello from CPP";
}

4.C++ファイルのラッピングに取り組んでいます。

C ++ファイルをラップしてIOS(swift)側にエクスポートするには

a。ObjectiveCファイルを作成して名前を付けますCpp_to_RN.m

名前をに変更Cpp_to_RN.m します Cpp_to_RN.mm

b。ファイルを開き、C++ファイルからWrapCpp_to_RN.mm 関数をラップする本文のコンテンツを記述します。sayHello

#import <Foundation/Foundation.h>
#import "WrapCpp_to_RN.h"
#import "Cpp_to_RN.hpp"@implementation WrapCpp_to_RN- (NSString *) sayHello {
  Cpp_to_RN fromCPP;
    std::string helloWorldMessage = fromCPP.sayHello();
    return [NSString
            stringWithCString:helloWorldMessage.c_str()
            encoding:NSUTF8StringEncoding];
}
@end

c。ヘッダーファイルを作成し、名前を付けますWrapCpp_to_RN.h

wrapSayHello関数をSwiftファイルにエクスポートします

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

5. iOS(Swift)側での作業

C++関数をReactNativeにエクスポートするには

a。Swiftファイルを作成し、名前を付けますSendCpp_to_RN.swift

注:Xcodeは、NativeModules-Bridging-Header.hファイルを作成するように要求します。

クラスSendCpp_to_RNを作成し、次のように宣言しますNSObject

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

requiresMainQueueSetup()アプリケーション実行時の警告を防ぐ関数を作成する

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

WrapCpp_to_RN()fromをラップする関数を記述しますWrapCpp_to_RN.mm

import Foundation@objc(SendCpp_to_RN)
class SendCpp_to_RN : NSObject {
    
  @objc static func requiresMainQueueSetup() -> Bool {
        return false
    }
  
  @objc func fromCpp(_ successCallback: RCTResponseSenderBlock) -> Void {
    successCallback([NSNull(), WrapCpp_to_RN().wrapSayHello() as Any])
    }}

b。Swiftファイルのラップ関数をReactNativeにエクスポートします

を使用してSwiftクラスとその関数をエクスポートするObjectiveCファイルを作成しますCallback

#import <React/RCTBridgeModule.h>
#import <Foundation/Foundation.h>
#import "UIKit/UIKit.h"
@interface RCT_EXTERN_MODULE(SendCpp_to_RN, NSObject)RCT_EXTERN_METHOD(fromCpp:(RCTResponseSenderBlock)successCallback)@end

c。SwiftをReactNativeに接続し、NativeModules-Bridging-Header.h ファイルを開きます

#import <React/RCTBridgeModule.h>#import <React/RCTViewManager.h>#import "WrapCpp_to_RN.h"

6.ReactNative側での作業

Swiftクラスとその関数を呼び出す

import React from 'react';
import {StyleSheet, Text, View, NativeModules, Button} from 'react-native';const App = () => {
  const onPress = () => {
    const {SendCpp_to_RN} = NativeModules;
    SendCpp_to_RN.fromCpp((_err, res) => console.log(res));
  };
  return (
    <View style={styles.container}>
      <Text> Practice !</Text>
      <Button title="C++ to React Native" color="#841584" onPress={onPress} />
    </View>
  );
};
const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
});
export default App;

これで完了です。アプリケーションを実行するだけです。

react-native run-ios

または、Xcodeの「実行」ボタンをクリックして、実行内容を確認してください。

私の記事がお役に立てば幸いです。お読みいただきありがとうございます。

 ソース:https ://betterprogramming.pub/native-modules-export-c-function-to-react-native-for-beginners-77e89934b210

#cpp #cplusplus #react 

黎 飞

黎 飞

1656984600

如何将函数从 C++ 导出到 React Native

今天,我继续分享我在 Native Module 和 C++ 方面的经验。

由于我们将看到很多为移动平台编写的 C/C++ 库,因此我们需要将它们实现到我们的 iOS 或 React Native 应用程序中。这就是为什么我想写一篇关于如何将一个函数从 C++ 导出到 React Native 的文章,它易于理解并且为初学者节省了时间。我将从一个新的 react native 应用程序开始

1.新建一个react native app,打开你的终端运行

npx react-native init NativeModules

2. 打开 Xcode 并导航到 NativeModules/ios/NativeModule.xcworkspace

3. 在 C++ 端工作

创建一个新的 C++ 文件并命名Cpp_to_RN.cpp

当我们创建一个新的 C++ 文件时,Xcode 会Cpp_to_RN.hpp 为我们创建一个头文件

首先,打开“ Cpp_to_RN.hpp文件,并创建一个包含没有主体的函数的类。

#ifndef Cpp_to_RN_hpp
#define Cpp_to_RN_hpp#include <stdio.h>
#include <string>class Cpp_to_RN {
public:
    std::string sayHello();
};#endif /* Cpp_to_RN_hpp */

然后打开Cpp_to_RN.cpp文件,写一个简单的函数“ sayHello()

#include "Cpp_to_RN.hpp"
std::string Cpp_to_RN::sayHello(){
    return "Hello from CPP";
}

4. 处理包装 C++ 文件。

包装 C++ 文件并将它们导出到 IOS (swift) 端

一个。创建一个Objective C文件并命名Cpp_to_RN.m

重命名Cpp_to_RN.m Cpp_to_RN.mm

湾。打开WrapCpp_to_RN.mm 文件并编写将包装sayHelloC++ 文件中的函数的正文内容。

#import <Foundation/Foundation.h>
#import "WrapCpp_to_RN.h"
#import "Cpp_to_RN.hpp"@implementation WrapCpp_to_RN- (NSString *) sayHello {
  Cpp_to_RN fromCPP;
    std::string helloWorldMessage = fromCPP.sayHello();
    return [NSString
            stringWithCString:helloWorldMessage.c_str()
            encoding:NSUTF8StringEncoding];
}
@end

C。创建头文件并命名WrapCpp_to_RN.h

将函数导出wrapSayHello到 Swift 文件

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

5. 在 iOS (Swift) 端工作

将 C++ 函数导出到 React Native

一个。创建一个 Swift 文件并命名SendCpp_to_RN.swift

注意:Xcode 会要求我们为我们创建一个NativeModules-Bridging-Header.h文件。

创建一个类SendCpp_to_RN并将其声明为NSObject

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

编写一个函数requiresMainQueueSetup()来防止我们运行应用程序时出现警告

#import <Foundation/Foundation.h>
@interface WrapCpp_to_RN : NSObject
- (NSString *) wrapSayHello;
@end

编写一个函数来包装WrapCpp_to_RN()fromWrapCpp_to_RN.mm

import Foundation@objc(SendCpp_to_RN)
class SendCpp_to_RN : NSObject {
    
  @objc static func requiresMainQueueSetup() -> Bool {
        return false
    }
  
  @objc func fromCpp(_ successCallback: RCTResponseSenderBlock) -> Void {
    successCallback([NSNull(), WrapCpp_to_RN().wrapSayHello() as Any])
    }}

湾。将 Swift 文件中的包装函数导出到 React Native

创建一个 Objective C 文件以导出 Swift 类及其函数,使用Callback

#import <React/RCTBridgeModule.h>
#import <Foundation/Foundation.h>
#import "UIKit/UIKit.h"
@interface RCT_EXTERN_MODULE(SendCpp_to_RN, NSObject)RCT_EXTERN_METHOD(fromCpp:(RCTResponseSenderBlock)successCallback)@end

C。将 Swift 连接到 React Native,打开NativeModules-Bridging-Header.h 文件

#import <React/RCTBridgeModule.h>#import <React/RCTViewManager.h>#import "WrapCpp_to_RN.h"

6. 在 React Native 方面工作

调用 Swift 类及其函数

import React from 'react';
import {StyleSheet, Text, View, NativeModules, Button} from 'react-native';const App = () => {
  const onPress = () => {
    const {SendCpp_to_RN} = NativeModules;
    SendCpp_to_RN.fromCpp((_err, res) => console.log(res));
  };
  return (
    <View style={styles.container}>
      <Text> Practice !</Text>
      <Button title="C++ to React Native" color="#841584" onPress={onPress} />
    </View>
  );
};
const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
});
export default App;

我们完成了,只需运行应用程序

react-native run-ios

或者只需单击 Xcode 上的“运行”按钮,看看我们做了什么。

希望我的文章对您有所帮助,感谢您的阅读时间。

 来源:https ://betterprogramming.pub/native-modules-export-c-function-to-react-native-for-beginners-77e89934b210

#cpp #cplusplus #react