android 全局变量，getApplicationContext 与 ClassCastException
按照Stack Overflow问答的建议，我创建了一个类（常量），并尝试声明并使用它作为全局变量，但它无法转换，找不到这个问题的任何好的答案，我尝试定义无论是清单文件中的“Constant”还是“.Constant”，这些定义都不起作用。
请帮帮我。
Constant con = ((Constant)getApplicationContext()); // failed to cast here
con.setClientid(Integer.parseInt(clientid));
import android.app.Application;
public class Constant extends Application {
private int gClientid;
public int getClientid() { return gClientid; }
public void setClientid(int cid) { gClientid = cid; }
}
显现
<application android:name=".Constant" android:icon="@drawable/icon">
Follow the advice from Stack Overflow question and answer, I create a class (Constant), and try to declare and use it as the global variable, but it failed to cast, can not find any good answer for this issue, I tried to define either "Constant" or ".Constant" in Manifest file, none of the definition works.
Please help me out.
Constant con = ((Constant)getApplicationContext()); // failed to cast here
con.setClientid(Integer.parseInt(clientid));
import android.app.Application;
public class Constant extends Application {
private int gClientid;
public int getClientid() { return gClientid; }
public void setClientid(int cid) { gClientid = cid; }
}
Manifest
<application android:name=".Constant" android:icon="@drawable/icon">
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评论（4）
正确的语法应该是 Constant con = (Constant) this.getApplication();在你的活动中。
The correct synthax should be Constant con = (Constant) this.getApplication(); inside your activity.
将 getApplicationContext() 替换为 getApplication()，您应该能够转换扩展应用程序的类。
Replace getApplicationContext() with getApplication() and you should be able to cast a class extending application.
我知道我正在回复旧帖子
但只是为了那些仍然遇到类似问题的人。
我认为他的问题是我的问题的一部分
是通过包含类的整个特定路径而不是“.Constant”来解决的。
前任。 “com.example.常量”
I know I'm answering to a old post,
but just for the people still getting similar problem.
I think his problem is the part of
My problem is solved by including whole specific path to the class instead of ".Constant".
ex. "com.example.Constant"