我有一个UICollectionView,其中每个单元格中都有一个图像。这些图像通过URL加载。但是,当某个单元格滚动出视线时,它会在重新加载之前显示另一单元格的图像一秒钟。我不知道为什么会这样。
这是我的代码:
我的UIImageView扩展要从url加载:
extension UIImageView {
public func imageFromUrl(urlString: String) {
Alamofire.request(.GET, urlString).responseJSON{
response in
if let tilbudimage = UIImage(data: response.data!){
self.image = tilbudimage
}
}
}
}
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UICollectionView:
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
print(DealArr.count)
return DealArr.count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("DealCell", forIndexPath: indexPath) as! DealCell
let deal = self.DealArr[indexPath.row]
cell.backgroundColor = UIColor.whiteColor()
cell.DealImage.imageFromUrl(deal["image"].string!)
cell.DealLabel.text = deal["title"].string! + …Run Code Online (Sandbox Code Playgroud) 它是package.json中的依赖项
"babel-eslint": "7.1.1",
"eslint": "3.17.1",
"eslint-config-airbnb": "14.1.0",
"eslint-plugin-import": "2.2.0",
"eslint-plugin-jsx-a11y": "4.0.0",
"eslint-plugin-react": "6.10.0",
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当我跑上npm run lint一个Linux 3.13.0-107-generic
/home/ubuntu/webview/analytics2/node_modules/eslint-config-airbnb-base/rules/best-practices.js:
Configuration for rule "no-unused-expressions" is invalid:
Value "data["0"].allowTaggedTemplates" has additional properties.
Referenced from: /home/ubuntu/webview/analytics2/node_modules/eslint-config-airbnb-base/index.js
Referenced from: airbnb
Referenced from: /home/ubuntu/webview/analytics2/.eslintrc
Error: /home/ubuntu/webview/analytics2/node_modules/eslint-config-airbnb-base/rules/best-practices.js:
Configuration for rule "no-unused-expressions" is invalid:
Value "data["0"].allowTaggedTemplates" has additional properties.
Referenced from: /home/ubuntu/webview/analytics2/node_modules/eslint-config-airbnb-base/index.js
Referenced from: airbnb
Referenced from: /home/ubuntu/webview/analytics2/.eslintrc
at validateRuleOptions (/home/ubuntu/webview/analytics2/node_modules/eslint/lib/config/config-validator.js:109:15)
at Object.keys.forEach.id (/home/ubuntu/webview/analytics2/node_modules/eslint/lib/config/config-validator.js:156:13)
at Array.forEach (native)
at Object.validate (/home/ubuntu/webview/analytics2/node_modules/eslint/lib/config/config-validator.js:155:35)
at load (/home/ubuntu/webview/analytics2/node_modules/eslint/lib/config/config-file.js:529:19)
at configExtends.reduceRight.e …Run Code Online (Sandbox Code Playgroud) 这是我的代码
class Message extends Component {
render() {
const { message, timeToRedirect } = this.props;
const time = timeToRedirect ? timeToRedirect : TIME_TO_REDIRECT // eslint flags this line
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我的想法是,如果参数timeToRedirect为零或未定义,我将为TIME_TO_REDIRECT变量分配一个常量time
但是,eslint将此标记为违反规则no-unneeded-ternary:"不必要地使用条件表达式进行默认分配".
我当然可以改写它
let time = timeToRedirect;
if (!timeToRedirect) {
time = TIME_TO_REDIRECT;
}
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但在我看来它不那么优雅.
有没有更好的方法来重写三元表达式?
我目前正在使用这些npm包
"babel-eslint": "7.1.0",
"eslint": "3.9.1",
"eslint-config-airbnb": "12.0.0",
"eslint-plugin-import": "1.16.0",
"eslint-plugin-jsx-a11y": "2.2.3",
"eslint-plugin-react": "6.5.0",
Run Code Online (Sandbox Code Playgroud) 在 Java 中,字符串有以下方法:
\n\nlength()/charAt(), codePointCount()/codePointAt()\nRun Code Online (Sandbox Code Playgroud)\n\nC++11有std::string a = u8"\xe5\xbe\x88\xe7\x83\xab\xe7\x83\xab\xe7\x9a\x84\xe4\xb8\x80\xe9\x94\x85\xe6\xb1\xa4";
但a.size()是char数组的长度,无法索引unicode char。
C++ 字符串中的 unicode 有解决方案吗?
\n给定一个类,我如何列出它的所有内部类?
class Car:
some_var = "var"
class Engine:
some_other_var = "var2"
class Body:
another_var = "var3"
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现在,Car 我希望能够列出或迭代其所有内部类 ( Engine, Body)
(Python 3.5)
我已经完成了以下测试,我发现我无法psutil用来检索有意义的数据。
基本上我试图运行这个命令来使用 python 报告容器内的可用内存。
我已经运行了 3 次测试,每次都使用不同的内存参数:
以下是测试:
docker run -m 10000000 -ti python:2.7 bash
docker run -m 100000000 -ti python:2.7 bash
docker run -m 800000000 -ti python:2.7 bash
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这是结果
> docker run -m 10000000 -ti python:2.7 bash
root@310de7b416cc:/# pip install psutil && python -c "import psutil; print psutil.virtual_memory().available"
Killed
> docker run -m 100000000 -ti python:2.7 bash
root@e7aade23c143:/# pip install psutil && python -c "import psutil; print psutil.virtual_memory().available"
Collecting psutil
Downloading psutil-5.3.1.tar.gz (397kB)
100% |????????????????????????????????| 399kB 2.8MB/s …Run Code Online (Sandbox Code Playgroud) 这是演示该问题的示例代码
.under {
position: absolute;
top: 10px;
left: 10px;
border: 2px solid blue;
width: 150px;
height: 150px;
}
.under:hover {
border: 10px solid green;
}
.over {
position: absolute;
z-index: 10;
top: 10px;
left: 10px;
width: 150px;
height: 150px;
border: 1px solid black;
}Run Code Online (Sandbox Code Playgroud)
<div>
<div class="under">
Hello!
</div>
<div class="over" data-comment="I am invisible">
</div>
</div>Run Code Online (Sandbox Code Playgroud)
当鼠标悬停在overdiv 上时,我希望underdiv 能够感知悬停事件,并在这种情况下相应地更改边框。
然而overdiv 显然拦截了悬停事件。是否有一个纯CSS解决方案将悬停事件传递给underdiv?
运行相关yarn add命令后,以下是新行packages.json:
"@types/classnames": "^2.2.7",
"classnames": "^2.2.6",
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然后我在打字稿文件中添加了这些行:
import * as classnames from 'classnames';
...
<div className={classnames('normal', 'on')}>
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现在我收到这个错误
类型错误:无法调用类型缺少调用签名的表达式。输入 '{ 默认:ClassNamesExport; }' 没有兼容的调用签名。TS2349
我的内容 tsconfig.json
{
"compilerOptions": {
"target": "es5",
"lib": [
"dom",
"dom.iterable",
"esnext"
],
"allowJs": true,
"skipLibCheck": true,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
"strict": true,
"forceConsistentCasingInFileNames": true,
"module": "esnext",
"moduleResolution": "node",
"resolveJsonModule": true,
"isolatedModules": true,
"noEmit": true,
"jsx": "preserve",
"experimentalDecorators": true
},
"include": [
"src"
]
}
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我该如何解决这个错误?
这是 terraform 状态文件的简化 json 文件(我们称之为 dev.ftstate)
{
"version": 4,
"terraform_version": "0.12.9",
"serial": 2,
"lineage": "ba56cc3e-71fd-1488-e6fb-3136f4630e70",
"outputs": {},
"resources": [
{
"module": "module.rds.module.reports_cpu_warning",
"mode": "managed",
"type": "datadog_monitor",
"name": "alert",
"each": "list",
"provider": "module.rds.provider.datadog",
"instances": []
},
{
"module": "module.rds.module.reports_lag_warning",
"mode": "managed",
"type": "datadog_monitor",
"name": "alert",
"each": "list",
"provider": "module.rds.provider.datadog",
"instances": []
},
{
"module": "module.rds.module.cross_region_replica_lag_alert",
"mode": "managed",
"type": "datadog_monitor",
"name": "alert",
"each": "list",
"provider": "module.rds.provider.datadog",
"instances": []
},
{
"module": "module.rds",
"mode": "managed",
"type": "aws_db_instance",
"name": "master",
"provider": "provider.aws",
"instances": [ …Run Code Online (Sandbox Code Playgroud) 我的后端服务器函数返回一个json对象列表给调用者.
我想使用JsonRequestBuilder与这个后端函数进行交互
我用这种方式定义了AsyncCallback
class MyCallBack extends AsyncCallback<List<MyObject>> {
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但是,JsonpRequestBuilder没有声明AsyncCallback,因为泛型类型被限制为<T extends JavaScriptObject>.List <MyObject>不满足此要求.
你对这个问题有什么建议吗?