Android 全局变量 [英] Android global variable

问题描述

我如何创建全局变量，在应用程序的整个生命周期中保持值不变，而不管哪个活动正在运行.

How can I create global variable keep remain values around the life cycle of the application regardless which activity running.

推荐答案

您可以扩展基础 android.app.Application 类并添加成员变量，如下所示:

You can extend the base android.app.Application class and add member variables like so:

public class MyApplication extends Application {

    private String someVariable;

    public String getSomeVariable() {
        return someVariable;
    }

    public void setSomeVariable(String someVariable) {
        this.someVariable = someVariable;
    }
}

在您的 android manifest 中，您必须声明实现 android.app.Application 的类(将 android:name=".MyApplication" 属性添加到现有的应用程序标记):

In your android manifest you must declare the class implementing android.app.Application (add the android:name=".MyApplication" attribute to the existing application tag):

<application 
  android:name=".MyApplication" 
  android:icon="@drawable/icon" 
  android:label="@string/app_name">

然后在您的活动中，您可以像这样获取和设置变量:

Then in your activities you can get and set the variable like so:

// set
((MyApplication) this.getApplication()).setSomeVariable("foo");

// get
String s = ((MyApplication) this.getApplication()).getSomeVariable();

这篇关于Android 全局变量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！