Leaflet:突然我收到此错误消息:无法加载资源:服务器响应状态为 403 ()

2024-04-01

突然我收到此错误消息,这对我来说很奇怪,因为我没有接触过地图部分:

Failed to load resource: the server responded with a status of 403 ()

在寻找线索时,我发现了这个过时的信息:

https://ninio.ninarski.com/2014/06/18/leaflet-tiles-failed-to-load-resource-the-server-responded-with-a-status-of-403-forbidden/ https://ninio.ninarski.com/2014/06/18/leaflet-tiles-failed-to-load-resource-the-server-responded-with-a-status-of-403-forbidden/

但我已经在使用了openstreetmap作为瓷砖供应商:

<TileLayer url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png" />

其他信息:

"@types/leaflet": "^1.7.9",
"leaflet": "^1.7.1",
"react": "18",
"react-dom": "18",
"react-leaflet": "4.0.0-beta.0",
"react-leaflet-fullscreen": "^2.0.2",
"react-leaflet-textpath": "^2.1.1",
node : v16.13.0
O.S.: Ubuntu 20.04 Desktop

这是完整的相关代码:

导入 * as React from 'react'; 从“传单”导入*作为传单 从“react-leaflet”导入{MapContainer、Marker、Popup、TileLayer}; 导入“./leaflet.css”

const position = [51.505, -0.09];

export default function Mapping(props) {
return (
    <MapContainer center={position} zoom={13}>
      <TileLayer
        attribution='&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
        url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
      />
      <Marker position={position}>
        <Popup>
          A pretty CSS3 popup. <br /> Easily customizable.
        </Popup>
      </Marker>
    </MapContainer>
  );

}

一部分leaflet.css文件是:

/* required styles */

.leaflet-pane,
.leaflet-tile,
.leaflet-marker-icon,
.leaflet-marker-shadow,
.leaflet-tile-container,
.leaflet-pane > svg,
.leaflet-pane > canvas,
.leaflet-zoom-box,
.leaflet-image-layer,
.leaflet-layer {
        position: absolute;
        left: 0;
        top: 0;
        }
.leaflet-container {
        /*overflow: hidden;*/
        width: 100%;
        height: 100%;
        }
.leaflet-tile,
.leaflet-marker-icon,
.leaflet-marker-shadow {
        -webkit-user-select: none;
           -moz-user-select: none;
                user-select: none;
          -webkit-user-drag: none;
        }
/* Prevents IE11 from highlighting tiles in blue */
.leaflet-tile::selection {
        background: transparent;
}
/* Safari renders non-retina tile on retina better with this, but Chrome is worse */
.leaflet-safari .leaflet-tile {
        image-rendering: -webkit-optimize-contrast;
        }
/* hack that prevents hw layers "stretching" when loading new tiles */
.leaflet-safari .leaflet-tile-container {
        width: 100%;
        height: 100%;
        -webkit-transform-origin: 0 0;
        }
.leaflet-marker-icon,
.leaflet-marker-shadow {
        display: block;
        }
/* .leaflet-container svg: reset svg max-width decleration shipped in Joomla! (joomla.org) 3.x */
/* .leaflet-container img: map is broken in FF if you have max-width: 100% on tiles */
.leaflet-container .leaflet-overlay-pane svg,
.leaflet-container .leaflet-marker-pane img,
.leaflet-container .leaflet-shadow-pane img,
.leaflet-container .leaflet-tile-pane img,
.leaflet-container img.leaflet-image-layer,
.leaflet-container .leaflet-tile {
        max-width: none !important;
        max-height: none !important;
        }

.leaflet-container.leaflet-touch-zoom {
        -ms-touch-action: pan-x pan-y;
        touch-action: pan-x pan-y;
        }
.leaflet-container.leaflet-touch-drag {
        -ms-touch-action: pinch-zoom;
        /* Fallback for FF which doesn't support pinch-zoom */
        touch-action: none;
        touch-action: pinch-zoom;
}
.leaflet-container.leaflet-touch-drag.leaflet-touch-zoom {
        -ms-touch-action: none;
        touch-action: none;
}
.leaflet-container {
        -webkit-tap-highlight-color: transparent;
}
.leaflet-container a {
        -webkit-tap-highlight-color: rgba(51, 181, 229, 0.4);
}
.leaflet-tile {
        filter: inherit;
        visibility: hidden;
        }
.leaflet-tile-loaded {
        visibility: inherit;
        }
.leaflet-zoom-box {
        width: 0;
        height: 0;
        -moz-box-sizing: border-box;
             box-sizing: border-box;
        z-index: 800;
        }
/* workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=888319 */
.leaflet-overlay-pane svg {
        -moz-user-select: none;
        }

.leaflet-pane         { z-index: 400; }

.leaflet-tile-pane    { z-index: 200; }
.leaflet-overlay-pane { z-index: 400; }
.leaflet-shadow-pane  { z-index: 500; }
.leaflet-marker-pane  { z-index: 600; }
.leaflet-tooltip-pane   { z-index: 650; }
.leaflet-popup-pane   { z-index: 700; }

.leaflet-map-pane canvas { z-index: 100; }
.leaflet-map-pane svg    { z-index: 200; }

.leaflet-vml-shape {
        width: 1px;
        height: 1px;
        }
.lvml {
        behavior: url(#default#VML);
        display: inline-block;
        position: absolute;
        }
/* control positioning */

.leaflet-control {
        position: relative;
        z-index: 800;
        pointer-events: visiblePainted; /* IE 9-10 doesn't have auto */
        pointer-events: auto;
        }
.leaflet-top,
.leaflet-bottom {
        position: absolute;
        z-index: 1000;
        pointer-events: none;
        }
.leaflet-top {
        top: 0;
        }
.leaflet-right {
        right: 0;
        }
.leaflet-bottom {
        bottom: 0;
        }
.leaflet-left {
        left: 0;
        }
.leaflet-control {
        float: left;
        clear: both;
        }
.leaflet-right .leaflet-control {
        float: right;
        }
.leaflet-top .leaflet-control {
        margin-top: 10px;
        }
.leaflet-bottom .leaflet-control {
        margin-bottom: 10px;
        }
.leaflet-left .leaflet-control {
        margin-left: 10px;
        }
.leaflet-right .leaflet-control {
        margin-right: 10px;
        }


/* zoom and fade animations */

.leaflet-fade-anim .leaflet-tile {
        will-change: opacity;
        }
.leaflet-fade-anim .leaflet-popup {
        opacity: 0;
        -webkit-transition: opacity 0.2s linear;
           -moz-transition: opacity 0.2s linear;
                transition: opacity 0.2s linear;
        }
.leaflet-fade-anim .leaflet-map-pane .leaflet-popup {
        opacity: 1;
        }
.leaflet-zoom-animated {
        -webkit-transform-origin: 0 0;
            -ms-transform-origin: 0 0;
                transform-origin: 0 0;
        }
.leaflet-zoom-anim .leaflet-zoom-animated {
        will-change: transform;
        }
.leaflet-zoom-anim .leaflet-zoom-animated {
        -webkit-transition: -webkit-transform 0.25s cubic-bezier(0,0,0.25,1);
           -moz-transition:    -moz-transform 0.25s cubic-bezier(0,0,0.25,1);
                transition:         transform 0.25s cubic-bezier(0,0,0.25,1);
        }
.leaflet-zoom-anim .leaflet-tile,
.leaflet-pan-anim .leaflet-tile {
        -webkit-transition: none;
           -moz-transition: none;
                transition: none;
        }

.leaflet-zoom-anim .leaflet-zoom-hide {
        visibility: hidden;
        }


/* cursors */

.leaflet-interactive {
        cursor: pointer;
        }
.leaflet-grab {
        cursor: -webkit-grab;
        cursor:    -moz-grab;
        cursor:         grab;
        }
.leaflet-crosshair,
.leaflet-crosshair .leaflet-interactive {
        cursor: crosshair;
        }
.leaflet-popup-pane,
.leaflet-control {
        cursor: auto;
        }
.leaflet-dragging .leaflet-grab,
.leaflet-dragging .leaflet-grab .leaflet-interactive,
.leaflet-dragging .leaflet-marker-draggable {
        cursor: move;
        cursor: -webkit-grabbing;
        cursor:    -moz-grabbing;
        cursor:         grabbing;
        }

/* marker & overlays interactivity */
.leaflet-marker-icon,
.leaflet-marker-shadow,
.leaflet-image-layer,
.leaflet-pane > svg path,
.leaflet-tile-container {
        pointer-events: none;
        }

.leaflet-marker-icon.leaflet-interactive,
.leaflet-image-layer.leaflet-interactive,
.leaflet-pane > svg path.leaflet-interactive,
svg.leaflet-image-layer.leaflet-interactive path {
        pointer-events: visiblePainted; /* IE 9-10 doesn't have auto */
        pointer-events: auto;
        }
/* visual tweaks */

.leaflet-container {
        background: #ddd;
        outline: 0;
        }
.leaflet-container a {
        color: #0078A8;
        }
.leaflet-container a.leaflet-active {
        outline: 2px solid orange;
        }
.leaflet-zoom-box {
        border: 2px dotted #38f;
        background: rgba(255,255,255,0.5);
        }


/* general typography */
.leaflet-container {
        font: 12px/1.5 "Helvetica Neue", Arial, Helvetica, sans-serif;
        }


/* general toolbar styles */

.leaflet-bar {
        box-shadow: 0 1px 5px rgba(0,0,0,0.65);
        border-radius: 4px;
        }
.leaflet-bar a,
.leaflet-bar a:hover {
        background-color: #fff;
        border-bottom: 1px solid #ccc;
        width: 26px;
        height: 26px;
        line-height: 26px;
        display: block;
        text-align: center;
        text-decoration: none;
        color: black;
        }
.leaflet-bar a,
.leaflet-control-layers-toggle {
        background-position: 50% 50%;
        background-repeat: no-repeat;
        display: block;
        }
.leaflet-bar a:hover {
        background-color: #f4f4f4;
        }
.leaflet-bar a:first-child {
        border-top-left-radius: 4px;
        border-top-right-radius: 4px;
        }
.leaflet-bar a:last-child {
        border-bottom-left-radius: 4px;
        border-bottom-right-radius: 4px;
        border-bottom: none;
        }
.leaflet-bar a.leaflet-disabled {
        cursor: default;
        background-color: #f4f4f4;
        color: #bbb;
        }
.leaflet-touch .leaflet-bar a {
        width: 30px;
        height: 30px;
        line-height: 30px;
        }
.leaflet-touch .leaflet-bar a:first-child {
        border-top-left-radius: 2px;
        border-top-right-radius: 2px;
        }
.leaflet-touch .leaflet-bar a:last-child {
        border-bottom-left-radius: 2px;
        border-bottom-right-radius: 2px;
        }

/* zoom control */

.leaflet-control-zoom-in,
.leaflet-control-zoom-out {
        font: bold 18px 'Lucida Console', Monaco, monospace;
        text-indent: 1px;
        }

.leaflet-touch .leaflet-control-zoom-in, .leaflet-touch .leaflet-control-zoom-out  {
        font-size: 22px;
        }

这是html file:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <meta http-equiv="original-trial" content=AhRSNW+2zbXlDahhAcj194oqlgDxj3TqG4sYwhsUdqldtNbZagboEjqIJZuUvBsIjtij4VSW0YvP5tGSpVgu6wgAAABzeyJvcmlnaW4iOiJodHRwczovL2dnYy53b3JsZDo0NDMiLCJmZWF0dXJlIjoiVW5yZXN0cmljdGVkU2hhcmVkQXJyYXlCdWZmZXIiLCJleHBpcnkiOjE2MzM0Nzg>
  </head>
  <body>
    <div id="app_G"></div>
    <div class='viewer' id='viewerG' title="Web Page" width= "480" height="480">
    <div id="map"></div>
    <script> const global = globalThis; </script>
    <script></script>
    <style>
      .leaflet-container {
        height: 800px;
        width: 800px;
       }
     </style>

  </body>
</html>

我得到的是grey map :

带有这些错误消息:

Failed to load resource: the server responded with a status of 403 ()

消除这一行:

    <meta http-equiv="original-trial" content=AhRSNW+2zbXlDahhAcj194oqlgDxj3TqG4sYwhsUdqldtNbZagboEjqIJZuUvBsIjtij4VSW0YvP5tGSpVgu6wgAAABzeyJvcmlnaW4iOiJodHRwczovL2dnYy53b3JsZDo0NDMiLCJmZWF0dXJlIjoiVW5yZXN0cmljdGVkU2hhcmVkQXJyYXlCdWZmZXIiLCJleHBpcnkiOjE2MzM0Nzg>

来自html页面产生这样的效果:

我们可以看到瓷砖轮廓的草图,但仍然看不到地图并收到错误消息:Failed to load resource: the server responded with a status of 404所以,我不明白这是否是解决问题的正确方向

如果我添加到html文件: 这一行:

<link rel="stylesheet" href="https://unpkg.com/[email protected] /cdn-cgi/l/email-protection/dist/leaflet.css"   integrity="sha512-puBpdR0798OZvTTbP4A8Ix/l+A4dHDD0DGqYW6RQ+9jxkRFclaxxQb/SJAWZfWAkuyeQUytO7+7N4QKrDh+drA=="   crossorigin=""/>

因此,由此产生的html页面是:

    <!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">


  </head>
  <link rel="stylesheet" href="https://unpkg.com/[email protected] /cdn-cgi/l/email-protection/dist/leaflet.css"   integrity="sha512-puBpdR0798OZvTTbP4A8Ix/l+A4dHDD0DGqYW6RQ+9jxkRFclaxxQb/SJAWZfWAkuyeQUytO7+7N4QKrDh+drA=="   crossorigin=""/>
  <body>
    <div id="app_G"></div>
    <div class='viewer' id='viewerG' title="Web Page" width= "480" height="480">
    <div id="map"></div>
    <script> const global = globalThis; </script>
    <script></script>
    <style>
      .leaflet-container {
        height: 800px;
        width: 100%;
       }
     </style>

  </body>
</html>

我仍然得到一个grey map :

与已经提到的错误消息Failed to load resource: the server responded with a status of 404 (Not Found)

根据这里的信息:https://operations.osmfoundation.org/policies/tiles/ https://operations.osmfoundation.org/policies/tiles/以下是要求openstreetmap瓷砖用途:

Requirements

    Heavy use (e.g. distributing an app that uses tiles from openstreetmap.org) is forbidden without prior permission from the [Operations Working Group](https://wiki.osmfoundation.org/wiki/Operations_Working_Group). See below for alternatives.
    Clearly display [license](https://wiki.openstreetmap.org/wiki/License) attribution.
    Do not actively or passively encourage copyright infringement.
    Calls to /cgi-bin/export may only be triggered by direct end-user action. (For example: “click here to export”.) The export call is an expensive (CPU+RAM) function to run and will frequently reject when server is under high load.
    Recommended: Do not hardcode any URL at tile.openstreetmap.org as doing so will limit your ability to react quickly if the service is disrupted or blocked.
    Recommended: add a link to https://www.openstreetmap.org/fixthemap to allow your users to report and fix problems in our data.

Technical Usage Requirements

    Valid [HTTP User-Agent](http://en.wikipedia.org/wiki/en:User_agent) identifying application. Faking another app’s User-Agent WILL get you blocked.
    If known, a valid [HTTP Referer](http://en.wikipedia.org/wiki/en:HTTP_Referer).
    DO NOT send no-cache headers. (“Cache-Control: no-cache”, “Pragma: no-cache” etc.)
    Cache Tile downloads locally according to HTTP Expiry Header, alternatively a minimum of 7 days.
    Maximum of 2 download threads. (Unmodified web browsers’ download thread limits are acceptable.)

Note: modern web browsers in standard configuration generally pass all the above technical requirements.

据我所知,我一直尊重他们所有人

这是完整的webpack.config.js file:

const 路径 = require('路径'); const cwd = process.cwd(); const HtmlWebpackPlugin = require('html-webpack-plugin'); const CopyPlugin = require("copy-webpack-plugin"); const MiniCssExtractPlugin = require('mini-css-extract-plugin'); const webpack = require('webpack');

function srcPaths(src) {
  return path.join(__dirname, src);
}

const isEnvProduction = process.env.NODE_ENV === 'production';
const isEnvDevelopment = process.env.NODE_ENV === 'development';

  // main process
var main_config = {
    mode: isEnvProduction ? 'production' : 'development',
    entry: './src/main/main.ts',
    target: 'electron-main',
    resolve: {
      extensions: ['.jsx', '.js', 'ts'],
    },
    externals: [
      {
        'utf-8-validate': 'commonjs utf-8-validate',
        bufferutil: 'commonjs bufferutil',
      },
    ],
    module: {
      rules: [
        {
          test: /\.ts$/,
          include: /src/,
          use: [{ loader: 'ts-loader' }]
        },
        {
          test: /\.(sass|less|css)$/i,
          use: [
            {
              loader: 'style-loader'
            },
            {
              loader: 'css-loader'
            },
            {
              loader: 'less-loader',
            },
          ],
        },
        {
          test: /\.s?css$/,
          use: [
            {
              loader: MiniCssExtractPlugin.loader,
              options: {
                sourceMap: true
              }
            },
            {
              loader: 'css-loader',
              options: {
                sourceMap: true
              }
            },
            {
              loader: 'sass-loader',
              options: {
                sourceMap: true
              }
            }
          ]
        },
        {
          test: /\.(png|jpe?g|svg|gif)$/i,
          use: [
            {
              loader: "file-loader",
              options: {
                name: "[path]/[name].[ext]",
              },
            },
          ],
        },
        {
          test: /\.geojson$/,
           use: [
             {
               loader: "json-loader",
             }
          ],
        }
      ]
    },
    output: {
      path: __dirname + '/dist',
      filename: 'main.js'
    },
    node: {
      __dirname: false,
      __filename: false
    },
};
  // renderer process
var renderer_config =  {
    mode: isEnvProduction ? 'production' : 'development',
    entry: {
      app: ['./src/app/index.tsx', 'react-app-polyfill/stable'],
      style: [
        './src/app/styles/index.css',
        path.resolve(__dirname, 'node_modules/leaflet/dist/leaflet.css')
      ]
    },
    //target: 'electron-renderer',
    //target: 'web',
    target: ['web', 'es5'],
    resolve: {
      extensions: ['.jsx', '.js', '.tsx', '.ts'],
    },
    output: {
      path: __dirname + '/dist/',
        //filename: 'renderer.js'
      filename: '[name].js',
    },
    externals: [
      {
        'utf-8-validate': 'commonjs utf-8-validate',
        bufferutil: 'commonjs bufferutil',
      },
    ],
    module: {
      rules: [
        {
          test: /\.(js|ts)x?$/,
          exclude: /node_modules/,
          use: {
            loader: 'babel-loader',
          },
        },
        {
          // css files
          test: /\.css$/i,
          use: [
            {
              loader: 'style-loader'
            },
            {
              loader: 'css-loader'
            },
          ],
        },
        {
          test: /\.(png|jpe?g|svg|gif)$/i,
          use: [
            {
              loader: "file-loader",
              options: {
                name: "[path]/[name].[ext]",
              },
            },
          ],
        },
        {
          // Font files
          test: /\.(woff|woff2|ttf|otf)$/,
          loader: 'file-loader',
          options: {
            name: '[hash].[ext]',
            outputPath: 'dist/assets/css/'
          }
        },
      ],
    },
    node: {
      __dirname: false,
      __filename: false
    },
    plugins: [
      new HtmlWebpackPlugin({
        filename: 'index.html',
        template: './src/app/index.html',
        inject:'body',
        chunks: ['app'],
      }),
      new MiniCssExtractPlugin({
        filename: '[name].css',
        chunkFilename: '[id].css',
        linkType: 'text/css',
      }),
      new CopyPlugin({
        patterns: [
          {
            from: path.resolve(__dirname, "./src/assets/css"),
            to: path.resolve(__dirname, "./dist/assets/css")
          },
        ],
        options: {
          concurrency: 100,
        },
      }),
    ]
}

module.exports = [
  main_config,
  renderer_config,
];

更新1)

更正其中的错字index.html : original-trial to origin-trial不幸的是并没有解决问题:

我仍然得到,例如:Failed to load resource: the server responded with a status of 403 () 2724.png:1

为了解决问题,我应该把注意力集中在哪里?


None

本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系:hwhale#tublm.com(使用前将#替换为@)

Leaflet:突然我收到此错误消息:无法加载资源:服务器响应状态为 403 () 的相关文章

  • 从脚本内更改自动热键托盘图标

    如何从 Autohotkey 脚本中将托盘图标更改为 my ico 例如 当脚本暂停时 为此 我在托盘菜单中提出了自己的 暂停脚本 菜单项 SingleInstance ignore Menu Tray Tip AutoCase 0 11
  • IE9-11 检测变换样式:preserve-3d

    我为一个项目制作了一个 3d 类型的菜单 自然 IE 会引起问题 因为 IE10 即使 3d 变换工作 也不支持变换样式 preserve 3d 我尝试了解决方法 通过对 3d 菜单容器的每个子元素应用变换 但至少可以说 动画看起来很糟糕
  • 文本溢出:省略号显示不同的字符

    我这里遇到了一些 CSS 问题 看这张图片 https www flickr com photos 125543025 N07 saved 1 在此图像中 我为文本 INTENSE TRAINING 添加了 CSS 样式 sample st
  • 我们什么时候应该在 Django 中使用“db_index=True”?

    当我们应该定义db index True在模型字段上 我正在尝试优化应用程序并且我想了解更多信息db index 什么情况下我们应该使用它 文档说使用db index True在模型字段上用于加速查找 但在存储和内存方面略有缺点 我们应该使
  • 如何制作过期/签名视频嵌入网址

    我是新来的 正在学习网络开发等等 我只知道如何将我的视频嵌入网站中 任何菜鸟都可以轻松获得源代码 他们也可以嵌入它 但在许多网站中 视频 src 均使用重定向器链接进行编码 例如 它会在一段时间后过期 在本例中是一天 我了解到这是一个签名网
  • Qt 布局,在小部件大小更改后调整到最小大小

    基本上我有一个QGridLayout里面有一些小部件 最重要的是 2 个标签 我用它们将图像绘制到屏幕上 好吧 如果用户愿意 他可以更改传入图像的分辨率 从而强制标签调整大小 我们假设标签的初始大小是320x240 用户将 VideoMod
  • bash:gitolite:找不到命令

    我正在尝试使用 Gitolite 在 Gitlab 中创建一个新分支 我完成安装步骤 当我遇到 设置 gitolite 部分时 我遇到了麻烦 我跟着这个link http sitaramc github com gitolite setup
  • 如何在 kubernetes 中将秘密标记为可选?

    来自文档 除非将秘密标记为可选 否则必须先创建秘密 然后再将其作为环境变量在 pod 中使用 引用不存在的 Secret 将阻止 pod 启动 如何将秘密标记为可选 您正在寻找的是 name ENV NAME valueFrom secre
  • xsi:type 属性搞乱了 C# XML 反序列化

    我使用 XSD exe 根据 XML 架构 xsd 文件 自动生成 C 对象 我正在反序列化 OpenCover 输出 但其中一个部分类未正确生成 这是导致异常的行
  • 一些基本的 PHP 问题 [已关闭]

    Closed 这个问题需要多问focused help closed questions 目前不接受答案 我只是有一些基本的 php 问题来加深我对学习的理解 但我找不到简单的答案 我有一个 php ajax 应用程序 它生成 mysql
  • If else 在 Web 网格列中

    如何在 webgrid 列中添加条件 if else grid GetHtml tableStyle table table bordered columns grid Columns grid Column RealName Name g
  • View.post(),以及当Runnables被执行时

    我最初的问题是需要知道我的根的高度和宽度View这样我就可以进行程序化的布局更改 就我的目的而言 我不一定需要在onCreate 对于我来说 以编程方式添加我的孩子就足够了View根布局完成后 因此我很乐意使用onWindowFocusCh
  • 将 Angular Web 组件 EventEmitter 监听到 javascript

    我在以下工具的帮助下创建了一个小型网络组件本文 https medium com IMM9O web components with angular d0205c9db08f使用角度元素 其中包括 Input and Output 我能够将
  • java'assert'和'if(){}else exit;'之间的区别

    java和java有什么区别assert and if else exit 我可以用吗if else exit代替assert 也许有点谷歌 您应该记住的主要事情是 if else 语句应该用于程序流程控制 而assert 关键字应该仅用于
  • R闪亮:使用闪亮的JS从数据表中获取信息

    我想读出所有列名称以及它们在数据表中显示的顺序 由于不同的原因 我无法使用 stateSave 等选项 我对 JS 没有什么把握 但我确信用它可以完成 所以我需要你帮助我 我尝试过类似的代码片段 datatable data callbac
  • React 错误:目标容器不是 DOM 元素

    我刚刚开始使用 React 所以这可能是一个非常简单的错误 但我们开始吧 我的html代码非常简单 load staticfiles
  • 从 JavaScript 中的 OnClientClick 事件中阻止 C# 中的 asp:Button OnClick 事件?

    我有一个asp Button在我的网页上 它调用 JavaScript 函数和代码隐藏方法 后者进行调用以导航到另一个页面 在 JavaScript 函数中 我正在检查条件 如果不满足这个条件 我想中止导航 以便OnClick方法未被调用
  • 自定义字符串查询操作的 Linq to NHibernate 可扩展性?

    我希望能够在 NHibernate Linq 表达式中使用自定义字符串查询 举例来说 这只是一个例子 我希望能够选择包含属性的实体 该属性是特定字符串的字谜 var myEntities EntityRepository AllEntiti
  • 计算包含字母/数字的行数

    我想要实现的目标很简单 但是解释起来有点困难 我不知道在 postgres 中这是否真的可能 我处于相当基础的水平 SELECT FROM WHERE LEFT JOIN ON HAVING 等等基本的东西 我正在尝试计算包含特定字母 数字
  • Java 和/C++ 在多线程方面的差异

    我读过一些提示 多线程实现很大程度上取决于您正在使用的目标操作系统 操作系统最终提供了多线程能力 比如Linux有POSIX标准实现 而windows32有另一种方式 但我想知道编程语言水平的主要不同 C似乎为同步提供了更多选择 例如互斥锁

随机推荐