學習 Android 編程的基礎知識

如果您想學習 Android 編程基礎知識, 您可以在網上找到一些資源. Android-Anfanger 教程面向有經驗的 Java 用戶, 所以你需要一些語言經驗. 它還需要自編程. Android SDK 沒什麼大不了的, 但你需要了解Java. 本文將引導您完成創建簡單 Android 應用程序的過程並學習如何創建 shareActionProvider.

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開發 Android 應用程序通常意味著使用 Java 編程語言. 創建 Android 應用程序, you’ll need an application development tool called an Android-Studio. 基於 Java 的課程將教您有關 Android 應用程序的各種組件, 包括動畫, 聲音, 相機和運動傳感器. 基於 Java 的課程還將幫助您開發智能手錶和在線最佳列表的應用程序. 最終, 您將能夠為所有這些設備開發應用程序，並使它們在您的設備上無縫運行.

除了學習Java, 您還可以學習如何使用 Android SDK 構建混合應用程序, 應用程序開發工具. 該工具包含Android SDK和Interneti-teenused. 取決於您的經驗水平, 您可以學習使用應用程序生成器來開發混合應用程序. 這個選項比較貴, 但允許您無需學習編程即可創建應用程序. 唯一的缺點是Java不像Swift那麼流行, Objective-C 或 Swift.

由於Android上的操作系統是基於Linux的, Java 是用於開發應用程序的主要語言. You can download Java Studio from Google for free, and the Java SE Development Kit and Runtime Environment (虛擬機) to build your Android application. Java is an Object-Oriented Programming language, and is the most popular programming language for Android. 實際上, Java is used to write apps for mobile devices. And if you want to create an iOS app, you can learn Swift without learning Java.

XML-Parsing

When you’re working on Android programming, you might be thinking that XML-Parsing is not necessary. 實際上, XML-Parsing is necessary in many cases. The Extensible Markup Language (XML) is a standard encoding format for sharing information on the internet. XML feeds are commonly provided by websites that frequently update content. Many network-connected apps must parse XML data to provide information to their users.

An XML parsing application will gather data and convert it into a formatted string, which can be used in many ways. A collection class, a database, or a database are all options. The resulting formatted string is formatted with minimal HTML. Some alternatives may be more efficient. A custom class may be necessary, since it uses a getResults() method to gather the assembled representation of data.

If you’re new to Android programming, you might be wondering how to use JSON or XML. To use the former, you’ll need to have Android Studio, but the revision of the SDK API does not matter. 開始, you can refer to the Android Developers website for instructions. You should be able to find basic JSON and XML parsing examples there.

Activity Lifecycle

在Android編程中, you can use the Activity Lifecycle to control your application’s behavior. This is the process by which an activity is brought back to the foreground and interacts with the user. While it is in the resumed state, it remains there until the focus is taken away from it, such as when the user makes a phone call, closes the app, or the screen turns off. 幸運的是, you can add lifecycle-aware functionality to your app to keep it running as long as the user is able to see it.

onStart() method is called when the Activity is about to be visible. It prepares the Activity for interactive operations. It is called before the activity’s onPause() 和on Resume() 方法. This method is used to trigger UI updates and save application data before the activity is killed by the system. 此外, 暫停() 當某件事吸引用戶焦點時調用該方法.

非活動活動也稱為 “不活躍的” 是那些對用戶不可見的. 如果應用程序的圖標被隱藏, 它將進入暫停狀態, 並且它不會在應用程序列表中可見. 此狀態通常與用戶單擊後退導航按鈕時相同. 當活動的可見性降至某個閾值以下時, it will be killed.

ShareActionProvider

如果您正在尋找一種在 Android 上共享內容的簡單方法, 您可能需要考慮使用 ShareActionProvider. 該類是 Android 支持庫的一部分, 支持較舊的 Android 版本. Share-Apps are simple apps that let users share content between two or more apps. The ShareActionProvider class is a useful tool for these apps. The underlying code for this class can be found here.

This class binds itself to the Action Bar menueintrag, or Options Menu. It appears as a to-the-right icon. 一旦安裝, the program starts automatically. You can also find the ShareActionProvider in the Android programmierung source code. It is displayed as a to-the-right icon and contains a list of applications that you can share. Once you’ve added the ShareActionProvider to your project, you can then launch it.

ShareActionProvider was added to the Android framework in ICS. It makes sharing data between Android apps much easier. It populates custom view lists and facilitates the addition of a share menu in the ActionBar. ShareActionProvider 還保存提供程序，以便您可以在想要共享時更改其意圖. 如果您使用 ActionBar 共享信息，這尤其有用.

XML 字符串

XML 代表可擴展標記語言, 它是一種輕量級標記語言，最初是為標准通用標記語言開發的 (SGML). XML 用標籤定義數據. 這種標記語言具有可擴展性並且易於開發, 廣泛用於Android編程中UI相關的數據. 本文概述了 XML 的基礎知識並展示瞭如何在 Android 編程中使用它.

XML解析方法

XML 解析對於 Android 開發人員來說是一項重要任務, 特別是如果您打算在 Web 應用程序中使用它. XML 文件包含一系列事件, 然後被解析並格式化為文本和其他數據. XML 解析器主要分為三種類型: 薩克斯, DOM, 和拉. 這些方法中的每一種都使用自己獨特的一組規則來處理數據並解析它.

雖然 JSON 廣泛用於 Web 服務, 一些應用程序仍然需要解析XML數據. 幸運的是, Android 有多種解析方法, 包括 XML PullParser API. XML 拉式解析比 DOM 解析器 API 需要更少的內存. 這些方法之間有一些共同的差異, 但您可以使用其中任何一個來完成相同的任務.

DOM 是 Android 中 XML 解析的另一種選擇. DOM 內存佔用較大, 但它沒有 SAX 複雜. 如果您的目標是創建一個僅顯示數據源子集的應用程序, SAX 方法可能就足夠了. 如果您打算將來解析更大的數據集, 然而, 使用 DOM 方法總是更好.