Android passing variables between activities
I want to pass one or more variables between activities in android. One solution is to use global variables, and it is explained here: Android global variable which I repeat here:
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;
}
}
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();
I want to use this and set a global variable in one of my activities when an item on a ListView is pressed. So I have this code:
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
.
.
.
((MyApplication) this.getApplication()).setSomeVariable("foo");
}
});
However I get an error which says "The method getApplication() is undefined for the type new AdapterV开发者_Python百科iew.OnItemClickListener(){}".
I would like to know what is the reason I get this error and how to fix it, or a better way of passing a variable from one activity to the other.
Thanks,
TJ
Inside an Anonymous Class you cant say this. u have to specifi the Class around the inner class.
like MyApplication.this.get..
when using:
class MyApplication {
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
((MyApplication) MyApplication.this.getApplication()).setSomeVariable("foo");
}
}
}
the "this." inside an annoymous inner class refering to the inner class itself.
Any particular reason you are not using Intent's? http://developer.android.com/guide/topics/fundamentals/activities.html#StartingAnActivity
You have the use MyClass.this.getApplication() if you've define the anonymous OnItemClickListener in a member function of MyClass. OnItemClickListener does not know about the application.
I don't think you need to cast it... Application is already there.
MyApplication.getSomeVariable();
should work just like any other class.
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