我需要在用户登录后为每个后续请求设置一些授权标头.
要为特定请求设置标头,
import {Headers} from 'angular2/http';
var headers = new Headers();
headers.append(headerName, value);
// HTTP POST using these headers
this.http.post(url, data, {
headers: headers
})
// do something with the response
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但是以这种方式为每个请求手动设置请求标头是不可行的.
如何在用户登录后设置标头集,并在注销时删除这些标头?
我RecyclerView不打电话onCreateViewHolder,onBindViewHolder即使是MenuViewHolder构造函数,因此没有出现RecyclerView.我把日志用于调试,没有显示日志.可能是什么问题?
我的适配器:
public class MenuAdapter extends RecyclerView.Adapter<MenuAdapter.MenuViewHolder> {
private LayoutInflater inflater;
List<Menu> data = Collections.emptyList();
public MenuAdapter(Context context, List<Menu> data) {
Log.i("DEBUG", "Constructor");
inflater = LayoutInflater.from(context);
Log.i("DEBUG MENU - CONSTRUCTOR", inflater.toString());
this.data = data;
for(Menu menu: this.data){
Log.i("DEBUG MENU - CONSTRUCTOR", menu.menu);
}
}
@Override
public MenuViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.row_menu, parent, false);
MenuViewHolder holder = new MenuViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(MenuViewHolder …Run Code Online (Sandbox Code Playgroud) 当我尝试运行app.jsexpress创建的文件时,我收到以下错误:
$ node app.js
node.js:134
throw e; // process.nextTick error, or 'error' event on first tick
^
Error: Cannot find module 'express'
at Function._resolveFilename (module.js:320:11)
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当我输入时,express --version我得到一个返回声明2.3.3.我使用npm来安装express.我不得不使用这些说明手动创建npm:
git clone http://github.com/isaacs/npm.git
cd npm
sudo make install
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错误是Error: Cannot find module 'express'.
在安装npm和express之后我是否需要做一些事情才能使快递看到由npm创建的模块?
Express全局安装.我用-g旗帜来安装它.
编辑:当我尝试时,"node -e require.paths"我得到:
[ '/home/user/.node_modules',
'/home/user/.node_libraries',
'/usr/local/lib/node' ]
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因此,节点未检测到npm安装.如何让节点检测npm安装?
我正在尝试运行非常简单的代码,但出现错误,我没有使用 create react 应用程序!
看起来我的 babel.config.js 文件被忽略了!
我的 html 文件
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>ReactJS</title>
</head>
<body>
<div id="app"></div>
<script src = 'bundle.js' ></script>
</body>
</html>
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我的 index.js 文件:
import React from 'react';
import { render } from 'react-dom';
render(<h1>Hello World!!</h1>, document.getElementById('app'));
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我的包json:
{
"name": "front",
"version": "1.0.0",
"main": "index.js",
"license": "MIT",
"scripts": {
"dev": "webpack-dev-server --mode development",
"build": "webpack-dev-server --mode production"
},
"dependencies": {
"@babel/cli": "^7.10.5",
"@babel/core": "^7.10.5",
"@babel/plugin-proposal-class-properties": "^7.10.4",
"@babel/preset-env": …Run Code Online (Sandbox Code Playgroud) 当我尝试构建运行以下命令的项目时:
ng build --environment=prod --aot=false --output-path="..." --base-href="..."
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你似乎不依赖@angular/core.
这是一个错误,但是,我不明白为什么因为它之前运作良好.
我试着这样做:
npm install @angular/core
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但我得到这个错误:
error at Error (native) error { Error: EACCES: permission denied, chown '' error at Error (native) error errno: -13, error code: 'EACCES', error syscall: 'chown', error Please try running this command again as root/Administrator. verbose exit [ -13, true ]
我也试图摆脱node_modules,然后安装npm:但我得到同样的错误.
当我运行以下命令时:
ng serve
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我有另一个错误:
The "@angular/compiler-cli" package was not properly installed. Error: Error: Cannot find module '@angular/compiler-cli'
这是我的package.json:
"ng": …Run Code Online (Sandbox Code Playgroud) 所以,我以前多次使用 Parcel,我从来没有遇到过问题。这一次它抛出了一些关于 SemVer 版本控制的愚蠢错误,我真的很想找到解决这个问题的解决方案。
我开始了新项目:安装了 npm w/ npm init(没有其他选项),然后安装了 Parcel npm install --save-dev parcel-bundler,然后创建了我的文件夹结构:
--node_modules
--index.html
--index.js
这是我的 package.json:
{
"name": "playground",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"dev": "parcel index.html"
},
"author": "",
"license": "ISC",
"devDependencies": {
"parcel-bundler": "^1.12.4"
}
}
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我已经配置了默认的 npm 脚本来运行包:"dev": "parcel index.html"并运行它。一切正常,但是当我通过<script src="/index.js"></script>它在 index.html 中连接我的 index.js 时,它会抛出很大的错误,说:
Run Code Online (Sandbox Code Playgroud)D:\workingSpace\playground\index.js: Invalid Version: undefined at new SemVer (D:\workingSpace\playground\node_modules\@babel\preset-env\node_modules\semver\semver.js:314:11) at compare (D:\workingSpace\playground\node_modules\@babel\preset-env\node_modules\semver\semver.js:647:10) at lt (D:\workingSpace\playground\node_modules\@babel\preset-env\node_modules\semver\semver.js:688:10) at D:\workingSpace\playground\node_modules\@babel\preset-env\lib\index.js:276:22 at Object.default (D:\workingSpace\playground\node_modules\@babel\helper-plugin-utils\lib\index.js:22:12) at …
我有点急于根据使用 yarn 的教程创建一个 React 应用程序。现在我要从头开始重新创建应用程序,因为我对 reactstrap 库不满意,我想切换到 react-bootstrap。
我已经重新安装了节点。但是,当我运行 create-react-app 时,它说使用“yarn”而不是“npm”,如下所示:
yarn start
Starts the development server.
yarn build
Bundles the app into static files for production.
yarn test
Starts the test runner.
yarn eject
Removes this tool and copies build dependencies, configuration files
and scripts into the app directory. If you do this, you can’t go back!
We suggest that you begin by typing:
cd react-test
yarn start
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我想使用 npm,因为它似乎使用更广泛,并且有更多基于它的示例。我是被纱线卡住了,还是可以继续使用 npm?
我在创建 React 应用程序时遇到错误。我如何解决它?
Microsoft Windows [Version 10.0.19044.1586]
(c) Microsoft Corporation. All rights reserved.
C:\Users\Olususi Victor>cd documents
C:\Users\Olususi Victor\Documents>cd react folder
C:\Users\Olususi Victor\Documents\React folder>npx create-react-app blog
You are running `create-react-app` 5.0.0, which is behind the latest release (5.0.1).
We no longer support global installation of Create React App.
Please remove any global installs with one of the following commands:
- npm uninstall -g create-react-app
- yarn global remove create-react-app
The latest instructions for creating a new app can be found here: …Run Code Online (Sandbox Code Playgroud) 基本上我的目标是实时改变油漆应用的物体颜色.为了实现这一目标,我遵循以下概念:
canny()方法找到了对象.findContours()边缘检测.drawContours()用于着色的对象.如果实现目标需要任何其他概念,请向我建议.我试过但没有得到精确的轮廓边缘.
原始输入:

预期产量:

当前输出:

我得到灰度图像,但我想在rgb模式.
这是我的代码:
package com.example.imageprocess;
import java.util.ArrayList;
import java.util.List;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.WindowManager;
public class MainActivity extends Activity implements CvCameraViewListener2 {
private Mat mRgba;
private Mat mIntermediateMat;
private Mat mGray;
private CameraBridgeViewBase mOpenCvCameraView;
private BaseLoaderCallback mLoaderCallback = …Run Code Online (Sandbox Code Playgroud) npm ×5
reactjs ×3
android ×2
angular ×2
javascript ×2
node.js ×2
npm-install ×2
yarnpkg ×2
angular-cli ×1
express ×1
html ×1
java ×1
node-modules ×1
npm-ci ×1
opencv ×1
parcel ×1