我正在使用angular-cli处理angular2项目。今天，我将以下版本更新为2.4.1。
"@angular/common": "~2.4.1",
"@angular/compiler": "~2.4.1",
"@angular/compiler-cli": "^2.4.1",
"@angular/core": "~2.4.1",
"@angular/forms": "~2.4.1",
"@angular/http": "~2.4.1",
"@angular/platform-browser": "~2.4.1",
"@angular/platform-browser-dynamic": "~2.4.1",
"@angular/router": "~3.4.1",
"angular-cli": "^1.0.0-beta.24"
当我使用2.0.0时，它不会出错，但是现在，它会出错GET http://localhost:4200/null 404 (Not Found)。
即使出现错误，它也可以正常运行。但是，我想知道为什么会发生，并解决此错误。如果有人知道这一点，请告诉我。谢谢 ：）
Packages.json
{
...
"private": true,
"dependencies": {
"@angular/common": "~2.4.1",
"@angular/compiler": "~2.4.1",
"@angular/compiler-cli": "^2.4.1",
"@angular/core": "~2.4.1",
"@angular/forms": "~2.4.1",
"@angular/http": "~2.4.1",
"@angular/material": "^2.0.0-beta.0",
"@angular/platform-browser": "~2.4.1",
"@angular/platform-browser-dynamic": "~2.4.1",
"@angular/router": "~3.4.1",
"@types/moment-timezone": "^0.2.33",
"angular-cli": "^1.0.0-beta.24",
"angular2-google-maps": "^0.17.0",
"bootstrap": "^3.3.7",
"bourbon": "^4.2.7",
"core-js": "^2.4.1",
"es6-promise": "^4.0.5",
"font-awesome": "^4.7.0",
"hammerjs": "^2.0.8",
"moment": "^2.17.1",
"moment-timezone": "^0.5.10",
"node-sass": "^3.13.0",
"primeng": "^1.1.0",
"pubnub-angular2": "^1.0.0-beta.6",
"quill": "^1.1.8",
"rxjs": "5.0.1",
"ts-helpers": "^1.1.1",
"typescript": "^2.0.10",
"typings": "^2.1.0",
"zone.js": "^0.7.4"
},
"devDependencies": {
"@types/hammerjs": "^2.0.33",
"@types/jasmine": "^2.2.30",
"@types/moment": "^2.13.0",
"@types/moment-timezone": "^0.2.33",
"@types/node": "^6.0.42",
"angular-cli": "^1.0.0-beta.24",
"bootstrap-sass": "^3.3.7",
"codelyzer": "~0.0.26",
"jasmine-core": "2.4.1",
"jasmine-spec-reporter": "2.5.0",
"karma": "1.2.0",
"karma-chrome-launcher": "^2.0.0",
"karma-cli": "^1.0.1",
"karma-jasmine": "^1.0.2",
"karma-remap-istanbul": "^0.2.1",
"protractor": "4.0.9",
"ts-loader": "^1.3.3",
"ts-node": "1.2.1",
"tslint": "4.2.0",
"typescript": "2.0.2"
}
}angular-cli.json
{
"project": {
"version": "1.0.0-beta.24",
"name": "five-delivery-admin"
},
"apps": [
{
"root": "src",
"outDir": "dist",
"assets": ["assets"],
"index": "index.html",
"main": "main.ts",
"test": "test.ts",
"tsconfig": "tsconfig.json",
"prefix": "app",
"mobile": false,
"styles": [
"styles.scss",
"../node_modules/hammerjs/hammer.min.js",
"../node_modules/primeng/resources/themes/omega/theme.css",
"../node_modules/primeng/resources/primeng.min.css",
"../node_modules/font-awesome/css/font-awesome.min.css",
"../node_modules/bootstrap/dist/css/bootstrap.min.css",
"../node_modules/quill/dist/quill.core.css",
"../node_modules/quill/dist/quill.snow.css",
"../node_modules/quill/dist/quill.bubble.css"
],
"scripts": [
"../node_modules/quill/dist/quill.min.js",
"../node_modules/hammerjs/hammer.min.js"
],
"environments": {
"source": "environments/environment.ts",
"dev": "environments/environment.ts",
"prod": "environments/environment.prod.ts"
}
}
],
"addons": [],
"packages": [],
"e2e": {
"protractor": {
"config": "./protractor.conf.js"
}
},
"test": {
"karma": {
"config": "./karma.conf.js"
}
},
"defaults": {
"styleExt": "scss",
"prefixInterfaces": false
}
}tsconfig.json
{
"compilerOptions": {
"declaration": false,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"allowSyntheticDefaultImports": true,
"lib": ["es6", "dom"],
"mapRoot": "./",
"module": "es6",
"moduleResolution": "node",
"outDir": "../dist/out-tsc",
"sourceMap": true,
"target": "es5",
"typeRoots": [
"../node_modules/@types"
]
}
}所以我只是花了很多时间才能弄清楚这一点，但是我做到了。
在执行更新后，这件事就发生在我身上，但与此无关。
绝对是从对具有空值的变量的引用中得出的，并且很可能是图像src属性。至少对我来说，这是我在应用程序各处使用的服务器中的值，而imgsrc是导致此问题的唯一原因，这很有意义。
我有类似的东西：
<img [src]="myData?.imageUrl">
我以为?安全运算符可以确保我不会出现空错误，通常这是这样做的，但是当您绑定到src属性时，浏览器会抛出一个错误，而不是编译器。编译器由于安全的运算符而使您可以将null绑定到它，但是由于src它是参考URL，因此浏览器仍在寻找该URL，并且控制台由于找不到URL而引发错误。relative/app/path/null
我找到了两种解决方法：
<img *ngIf="myData" [src]="myData.imageUrl"/>如果没有数据，整个映像及其src属性甚至都不会加载，从而完全避免了此问题）<img src="{{ myData?.imageUrl }}"/>在此解决方案中，请注意，您仍然需要安全的运算符，因为编译器将按预期方式否则引发错误，但现在如果该值为null，则src=""代替null，这是有效的HTML，并且不会引发引用错误）希望这可以帮助！
本文收集自互联网，转载请注明来源。
如有侵权，请联系 [email protected] 删除。
我来说两句