I know that this Question is repeated but I can't find the answer in Internet.
I want to call a method from another class.
I've Class1 and Class2.
In Class 2 I've that method:
public void UpdateEmployee(){
//some code
}
I want to call that method from Class1.
Thanks for any answer.
----EDIT----
final Button btnUpdate = (Button)findViewById(R.id.btnUpd);
btnUpdate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Employee updEmple = new Employee();
updEmple.UpdateEmployee();
}
});
----LogCat---
05-28 16:30:44.030: E/AndroidRuntime(25198): FATAL EXCEPTION: main
05-28 16:30:44.030: E/AndroidRuntime(25198): java.lang.NullPointerException: println needs a message
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.util.Log.println_native(Native Method)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.util.Log.v(Log.java:116)
05-28 16:30:44.030: E/AndroidRuntime(25198): at and.net.Employee.UpdateEmployee(Employee.java:77)
05-28 16:30:44.030: E/AndroidRuntime(25198): at and.net.AndActivity$2.onClick(AndActivity.java:51)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.view.View.performClick(View.java:2485)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.view.View$PerformClick.run(View.java:9080)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.os.Handler.handleCallback(Handler.java:587)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.os.Handler.dispatchMessage(Handler.java:92)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.os.Looper.loop(Looper.java:123)
05-28 16:30:44.030: E/AndroidRuntime(25198): at android.app.ActivityThread.main(ActivityThread.java:3683)
05-28 16:30:44.030: E/AndroidRuntime(25198): at java.lang.reflect.Method.invokeNative(Native Method)
05-28 16:30:44.030: E/AndroidRuntime(25198): at java.lang.reflect.Method.invoke(Method.java:507)
05-28 16:30:44.030: E/AndroidRuntime(25198): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-28 16:30:44.030: E/AndroidRuntime(25198): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-28 16:30:44.030: E/AndroidRuntime(25198): at dalvik.system.NativeStart.main(Native Method)
eric.itzhak
You should use the following code :
Class2 cls2 = new Class2();
cls2.UpdateEmployee();
In case you don't want to create a new instance to call the method, you can decalre the method as static and then you can just call Class2.UpdateEmployee().
And, if you don't want to instantiate Class2, declare UpdateEmployee as static and call it like this:
Class2.UpdateEmployee();
However, you'll normally want to do what @parag said.
Parag Chauhan
In Class1:
Class2 inst = new Class2();
inst.UpdateEmployee();
Add this in MainActivity.
Intent intent = new Intent(getApplicationContext(), Heightimage.class);
startActivity(intent);
来源:https://stackoverflow.com/questions/10787159/android-call-an-method-from-another-class