如何从另一个类调用对象并将其添加？

Question

I'm new for android java coding. I'm try to do menu list where just have tick box, and once tick the items, n press next, it should go to view layout and show items and the total of the item selected, then press next it should open details page where user must put their details n press send button to send via email. I don't know how to call the items from menu to Cart and to confirmation class.

This is menu.java .

 import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; public class MenuActivity extends Activity { Button btnorder; Button btnback; Button btnlinkcart; protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.menu); btnlinkcart = (Button) findViewById(R.id.button1); btnback = (Button) findViewById(R.id.button2); // back button click event btnback.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { Intent intent = new Intent(MenuActivity.this, MainActivity.class); startActivity(intent); } }); // Link to Cart Screen btnlinkcart.setOnClickListener(new View.OnClickListener() { public void onClick(View view) { Intent i = new Intent(getApplicationContext(), ViewActivity.class); startActivity(i); finish(); } }); } } 

This is Cart.java

 import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; public class ViewActivity extends Activity { Button btnconfirm; protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.cart); btnconfirm = (Button) findViewById(R.id.button1); // Link to Cart Screen btnconfirm.setOnClickListener(new View.OnClickListener() { public void onClick(View view) { Intent i = new Intent(getApplicationContext(), ConfirmActivity.class); startActivity(i); finish(); } }); } } 

This is cart.xml

 <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:background="@drawable/wallpaper" > <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:text="Confirm" /> </RelativeLayout> 

This is menu.xml

 <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@drawable/wallpaper" android:orientation="vertical" > <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:text="Next" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_alignParentLeft="true" android:text="Back" /> <CheckBox android:id="@+id/checkBox1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" android:layout_marginTop="28dp" android:text="Pizza (Large) RM30.00" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/checkBox1" android:layout_marginTop="20dp" android:text="Pizza (Mediume) RM20.00" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/checkBox2" android:layout_marginTop="20dp" android:text="Pizza (Personal) RM10.00" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/checkBox3" android:layout_marginTop="20dp" android:text="Chicken Wings RM12.00" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/checkBox4" android:layout_marginTop="19dp" android:text="Garlic Bread RM6.00" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox6" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/checkBox5" android:layout_marginTop="20dp" android:text="Soft Drink (Large) RM5.00" android:textAppearance="?android:attr/textAppearanceLarge" /> <CheckBox android:id="@+id/checkBox7" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/checkBox6" android:layout_marginTop="19dp" android:text="Soft Drink (Medium) RM4.00" android:textAppearance="?android:attr/textAppearanceLarge" /> </RelativeLayout> 

Answer 1

Make the variable you want to get in the menu class static, then in the cart class you can get them like this:

menu.variableFromMenuClass

Answer 2

 public static ArrayList<YourObject>  selectItemList= new ArrayList<YourObject>();


 on selectItem(){
 //each Item you add here 
 selectedList.add(selectedObject);
 }

 on disselectItem(){
//remove if exist in list
 selectedList.remove(disselectedOject);
 }


sendemail(){
 send your public static selecteditem list.

}

This is the algorithm you have to write simple.