```kotlin val mutableList = mutableListOf<Int>() ``` 或者 ```kotlin val mutableList = listOf(1, 2, 3).toMutableList() ``` 2.使用add方法向列表中添加元素。在Kotlin中,add方法用于将指定的元素添加到列表的末尾。 示例代码: ```kotlin mutableList.add(4) mutableList.add(5) ``` 在上述示例...
object DataRepository { var data = listOf(1,2,3) } 1. 2. 3. 对象声明的特点是object关键字后面跟着一个名称。就像声明一个变量那样,但是对象声明不是一个表达式,不能把对象声明放在赋值语句的右边。 利用AndroidStudio 的 Show Kotlin Bytecode 功能,看一下对应的 .java 文件: public final class DataR...
Kotlin不允许往集合中添加null值,虽然签名做了空判断,但是怕在调用addAll时对应值仍然被修改为null(脑子有问题)。 解决方案 方式1. data.list?.let(mDataList::addAll) 方式2. data.list?.let { node -> mDataList.addAll(node) } 方式3. data.list?.let { mD...
If we come from the Java world, these lists may confuse us. Also, when we try to add an element to a list in Kotlin, it’s not always as straightforward as calling theadd()method in Java. For example, sometimes, thelist.add()line may not compile. Next, we’ll briefly introduce th...
MutableList 是Kotlin 中的一个接口,它继承自 List 接口,并添加了可变操作的方法。clear() 和addAll() 是MutableList 接口中用于修改列表内容的两个常用方法。 基础概念 clear(): 这个方法用于移除列表中的所有元素,使得列表变为空。 addAll(): 这个方法用于将一个集合中的所有元素添加到列表的末尾。 行为解释 ...
1 + # ZXing-C++ Kotlin/Native Library 2 + 3 + ## Install 4 + 5 + The easiest way to use the library is to fetch if from _mavenCentral_. Simply add 6 + 7 + ```gradle 8 + implementation("io.github.zxing-cpp:kotlin-native:2.2.1") 9 + ``` 10 + 11 + to ...
In Kotlin, as in every language, we have predefined operators to perform certain operations. The most typical are the addition (+), subtraction (-), multiplication (*) or division (/), but there are a few more. In some languages, such as Java, these operators are limited to certain ...
2 changes: 2 additions & 0 deletions 2 core/common/src/main/kotlin/eu/kanade/tachiyomi/util/system/DeviceUtil.kt Original file line numberDiff line numberDiff line change @@ -81,6 +81,8 @@ object DeviceUtil { "com.zui.resolver", // Infinix "com.transsion.resolver", // Xiaomi Redmi...
怎么样在recyclerview 里添加header Kotlin classAllCategoryAdapter(val categoryList : List<AllCategoryBean>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {privateval TYPE_HEADER : Int = 0privateval TYPE_LIST : Int = 1override fun getItemViewType(position: Int): Int {if(position == 0) ...
In theAndroidview ofAndroid Studio, openapp > kotlin+java > com.example.app > MainActivity. Set theAuthenticationModeto.API_KEY. MainActivity.kt Expand Use dark colors for code blocks classMainActivity:ComponentActivity() {privateenumclassAuthenticationMode{ API_KEY, USER_AUTH }privatevalauthenticat...