小编Has*_*sef的帖子

I'm trying to test the HTML Application, my build.gradle dependencies are:

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
    compile "org.jetbrains.ktor:ktor-core:$ktor_version"
    compile 'org.jetbrains.kotlinx:kotlinx-html:0.6.4'
    compile "org.jetbrains.ktor:ktor-netty:$ktor_version"
    compile "org.apache.commons:commons-email:1.4"
    compile "org.slf4j:slf4j-simple:1.7.25"
    compile "ch.qos.logback:logback-classic:1.2.1"
    testCompile group: 'junit', name: 'junit', version: '4.12'
}

I got the below error while running gradle build:

Could not find org.jetbrains.kotlinx:kotlinx-html:0.6.4

what is the error here?

在学习F#和阅读此页,我发现这个代码:

type MyGenericClass<'a> (x: 'a) =
   do printfn "%A" x

我不理解它的含义'a是否与任何lifetime概念相关rust或完全不同？

我有这两个清单:

val forecast = listOf(30, 21, 29, 31, 40, 48, 53, 47, 37, 39, 31, 29)
val actual = listOf(27, 31, 27, 26, 21, 13, 21, 18, 33, 35, 40, 36)

并且需要计算每个月的预测误差,这是forecast-actual我尝试过以下内容:

var errors: MutableList<Double> = mutableListOf<Double>()

actual
      .forEachIndexed { index, d ->  forecast[index] - d}
      .let { i -> errors.add(i) }

但没有奏效,因为i结果forEachIndexed是Unit不是Double:(

有没有办法在Julia和Rust之间进行交互,这种方式允许:

1. 从Julia调用/执行Rust函数
2. 从Rust调用/执行Julia

谢谢

交叉引用Rust 论坛，我正在生成一个HashMap，就像在这个操场/下面的代码中一样。如何map根据 对生成的结果进行排序keys，在我的情况下是基于Dimension, Location：

use std::collections::HashMap;

#[derive(Debug, Eq, PartialEq, Hash, Clone)]
struct Dimension {
    item: String,
    color: String,
    size: String,
    part_number: String
}

#[derive(Debug)]
struct Delivery {
    variant: Dimension,
    location: String,
    quantity: i32,
}

pub fn main() {
    let data = vec![
        Delivery {
            variant: Dimension {item: String::from("A"),
                                color: String::from("B"),
                                size: String::from("C"),
                                part_number: String::from("D")},
            location: String::from("L"),
            quantity: 10,
        },
        Delivery {
            variant: Dimension {item: String::from("A"),
                                color: String::from("B"),
                                size: …

我有这个游乐场：https://go.dev/play/p/uEpYEWaQaV0 但不明白问题是什么以及为什么它不起作用！我收到错误：

invalid character entity &ccb

我的代码是：

package main

import (
    "encoding/xml"
    "fmt"
)

type catalog struct {
    Id string `xml:"id"`
}

type price struct {
    Subtotal    int    `xml:"subtotal"`
    Currency    string `xml:"currency"`
    Total       int    `xml:"total"`
    PriceStatus string `xml:"price_status"`
}

type image struct {
    Url string `xml:"url"`
    Id  int    `xml:"id"`
}

type product struct {
    Id         int    `xml:"id"`
    RetailerId int    `xml:"retailer_id"`
    Image      image  `xml:"image"`
    Price      int    `xml:"price"`
    Currency   string `xml:"currency"`
    Name       string `xml:"name"`
    Quantity   int    `xml:"quantity"`
}

type order struct …

如下图所示，我需要操纵构造函数的输入参数，commandsList但即使使用this.，它也会提供未知变量。

我很伤心，它接受了此参数，并将其passed it作为同一类中另一个方法的输入参数，这迫使我编写一个单独的方法来处理所需的几行内容。

有什么帮助吗？

按照这个接受的答案,我能够得到tabLyout如下:

我现在需要的是能够根据片段位置更改按钮文本,例如,如果位置为零,则Back不应出现,如果位置是最后一个,Next则应替换为Done

我用过ViewPager.OnPageChangeListener但不适用于我,下面是完整的代码:

public class Slider extends AppCompatActivity {

    private TabLayout tabLayout;
    private ViewPager viewPager;
    private Button leftBtn, rightBtn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.start_up);

        leftBtn = (Button) findViewById(R.id.left_btn);
        rightBtn= (Button) findViewById(R.id.right_btn);

        viewPager = (ViewPager) findViewById(R.id.viewpager);
        setupViewPager(viewPager);

        tabLayout = (TabLayout) findViewById(R.id.tabLayout);
        tabLayout.setupWithViewPager(viewPager);
    }

   // This is not working, even the `Toast` not appearing
    private ViewPager.OnPageChangeListener listener = new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, …

如果location是null,我想执行一个msg ,如果它不是null,我想执行另一个msg,所以我尝试使用elvis-operator作为a?.let{} ?: run{}语句,但是run部分是不可访问的,它告诉我它不是必需的也不是非-nullable!

我得到错误的函数是:

getLocation(
           context,
                { location ->
                    location?.let {
                        msg = ("As of: ${Date(it.time)}, " +
                                "I am at: http://maps.google.com/?q=@" +
                                "${it.latitude}, ${it.longitude}, " +
                                "my speed is: ${it.speed}")
                    } ?: run { . // Getting error here
                        msg = "Sorry, it looks GPS is off, no location found\""
                    }

                    sendSMS(
                            context,
                            address,
                            msg,
                            subId
                    )
                }
        )

个getLocation功能是:

object UtilLocation {
    private lateinit var l : …

这是一个Expanded panel看起来像这样的材料设计：

我想用 做一个类似的Flutter，不确定我是否必须从下面的代码开始或知道如何完成它！

new ExpansionPanelList(
  children: <ExpansionPanel>[
    new ExpansionPanel(
      headerBuilder: (BuildContext context, bool isExpanded) {
            isExpanded = true;
            return new ListTile(
            // leading: item.iconpic,
            title: new Text(
            "First",
            textAlign: TextAlign.left,
            style: new TextStyle(
            fontSize: 20.0,
            fontWeight: FontWeight.w400,
            ),
            ));
          },
      body: new Text("school"),
      isExpanded: true,
    ),
    new ExpansionPanel(
      headerBuilder: (BuildContext context, bool isExpanded) {
        isExpanded = true;
        return new ListTile(
          // leading: item.iconpic,
            title: new Text(
              "Second",
              textAlign: TextAlign.left,
              style: new TextStyle(
                fontSize: 20.0, …