我该如何创建全局变量,使其在应用程序的生命周期内保持值不变,而不管运行哪个活动。
我该如何创建全局变量,使其在应用程序的生命周期内保持值不变,而不管运行哪个活动。
技术上讲,这并没有回答问题,但我建议使用Room数据库而不是任何全局变量。 https://developer.android.com/topic/libraries/architecture/room.html 即使你只需要存储一个全局变量,而且这并不是什么大事,但使用Room数据库是保持活动生命周期中的值最优雅、本地化和得到最好支持的方式。 它将有助于防止许多问题,特别是数据完整性。 我知道数据库和全局变量是不同的,但为了代码维护、应用程序稳定性和数据完整性,请使用Room。
import android.app.Application;
public class Globals extends Application
{
private static Globals instance = null;
private static int RecentCompaignID;
private static int EmailClick;
private static String LoginPassword;
static String loginMemberID;
private static String CompaignName = "";
private static int listget=0;
//MailingDetails
private static String FromEmailadd="";
private static String FromName="";
private static String ReplyEmailAdd="";
private static String CompaignSubject="";
private static int TempId=0;
private static int ListIds=0;
private static String HTMLContent="";
@Override
public void onCreate()
{
super.onCreate();
instance = this;
}
public static Globals getInstance()
{
return instance;
}
public void setRecentCompaignID(int objRecentCompaignID)
{
RecentCompaignID = objRecentCompaignID;
}
public int getRecentCompaignID()
{
return RecentCompaignID;
}
public void setLoginMemberID(String objloginMemberID)
{
loginMemberID = objloginMemberID;
}
public String getLoginMemberID()
{
return loginMemberID;
}
public void setLoginMemberPassword(String objLoginPassword)
{
LoginPassword = objLoginPassword;
}
public String getLoginMemberPassword()
{
return LoginPassword;
}
public void setEmailclick(int id)
{
EmailClick = id;
}
public int getEmailClick()
{
return EmailClick;
}
public void setCompaignName(String objCompaignName)
{
CompaignName=objCompaignName;
}
public String getCompaignName()
{
return CompaignName;
}
public void setlistgetvalue(int objlistget)
{
listget=objlistget;
}
public int getlistvalue()
{
return listget;
}
public void setCompaignSubject(String objCompaignSubject)
{
CompaignSubject=objCompaignSubject;
}
public String getCompaignSubject()
{
return CompaignSubject;
}
public void setHTMLContent(String objHTMLContent)
{
HTMLContent=objHTMLContent;
}
public String getHTMLContent()
{
return HTMLContent;
}
public void setListIds(int objListIds)
{
ListIds=objListIds;
}
public int getListIds()
{
return ListIds;
}
public void setReplyEmailAdd(String objReplyEmailAdd)
{
ReplyEmailAdd=objReplyEmailAdd;
}
public String getReplyEmailAdd()
{
return ReplyEmailAdd;
}
public void setFromName(String objFromName)
{
FromName=objFromName;
}
public String getFromName()
{
return FromName;
}
public void setFromEmailadd(String objFromEmailadd)
{
FromEmailadd=objFromEmailadd;
}
public String getFromEmailadd()
{
return FromEmailadd;
}
}
太简单了!!!
如果你想要将某些变量作为全局变量来访问,你可以将它们声明为静态变量。现在,你可以通过使用
classname.variablename;
public class MyProperties {
private static MyProperties mInstance= null;
static int someValueIWantToKeep;
protected MyProperties(){}
public static synchronized MyProperties getInstance(){
if(null == mInstance){
mInstance = new MyProperties();
}
return mInstance;
}
}
MyProperites.someValueIWantToKeep;
就是这样!;)
getInstance()
上使用了synchronized
,而其他答案则没有。相应地进行了投票。 - user2297550