自全球应用课间与＆QUOT; android.app.Application不能转换到＆QUOT; [英] Custom global Application class breaks with "android.app.Application cannot be cast to"

问题描述

我有一个看起来像这样一个自定义的全局类

I have a custom global class which looks like this

import android.app.Application;

public class MyApp extends Application {

    public String MainAct;

    public String getMainAct() {
        return MainAct;
    }

    public void setMainAct(String mainAct) {
        MainAct = mainAct;
    }
}

我想preserve通过另一个活动在的onCreate 方法的字符串在这个类。

I want to preserve a string in this class via another Activity in its onCreate method.

    String local = "myLocalVariable";
    ((MyApp) getApplication()).setMainAct(local); //breaks here!!!
    String name = ((MyApp) getApplication()).getMainAct();

它打破了与错误的标记线：致：java.lang.ClassCastException：android.app.Application不能转换为com.xxx.yyy.global.MyApp

我检查了code五次，我无法找到错误的任何地方。谁能告诉我在哪里，错误的是？！

I've checked the code for five times and I cannot find error anywhere. Can anyone tell me where the error is?!

感谢

推荐答案

该错误提示按 getApplication 返回的对象的类型是安卓.app.Application 。一个可能的原因是，你无法定义清单中的应用程序。请确保您的清单包括一些在该行：

The error states that the type of the object returned by getApplication is android.app.Application. A possible cause for this is that you failed to define the application in the manifest. Make sure that your manifest includes something in the lines of:

<application android:name=".MyApp"...
</application>

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