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POAccessing an Instance's Variable from another Activity - Android Developement
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copied!<p>I have creted a program that has 3 Activities: MainActivity, UpgradeActivity and UpgradesActivity.</p> <p>Main Activity contains a timer and it also contains an instance of a Vehicle class.</p> <pre><code>public class MainActivity extends Activity { TextView vehicleSpeed, vehicleName, vehicleDistance, vehicleLocation, vehicleStatus, vehicleNews, vehicleInfo, vehicleMoney; ProgressBar vehicleFuel; public static Vehicle vehicle; boolean launched; public static PartType selectedType; Handler handler = new Handler(); </code></pre> <p>I have a button in MainActivity, that when pressed will take me to a page where i can select which part of the vehicle i wish to upgrade. For example i select: Engine. The engine Button takes me to the Upgrade Activity. In this activity i can buy the upgrade which should be applied to the vehicle in MainActivity. For the purpose of this question, lets say it set vehicles speed to +3.</p> <p>My question is in regards to how to access the vehicle instance inside the MainActivity from the UpgradeActivity. I've tried making the instance static but that didn't work. How do i gain access and how can i change the vehicles variables from the other activities.</p> <p>Here is where i am making the instance:</p> <pre><code>@Override protected void onCreate(Bundle savedInstanceState) { this.selectedType = PartType.Antenna; this.launched = false; super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); vehicle = new Vehicle(); vehicle.setupCar(); </code></pre> <p>Here is where i am accessing the variable in Upgrades, it call the upgrade function inside of the Vehicle Class:</p> <pre><code> buyUp1.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { MainActivity.vehicle.upgradeEngine(MainActivity.vehicle.engineLvl + 1); Intent activityChangeIntent = new Intent(UpgradesActivity.this, MainActivity.class); UpgradesActivity.this.startActivity(activityChangeIntent); } }); </code></pre> <p>And this is the function within the Vehicle Class:</p> <pre><code> public void upgradeEngine(int lvl) { engineLvl += 3; engine = parts.getEngine(lvl); } </code></pre> <p>The vehicle Stores an integer called: EngineLvl. This determines what level the cars engine is. The level is incremented by +3 everytime the engine is updated. </p> <p>The problem is that the engine level never changes. Even if i make the Vehicle instance and all of the variables within vehicle STATIC;</p> <p>MAINACTIVITY:</p> <p>Vehicle Button to UpgradesActivity</p> <p>UPGRADESACTIVITY:</p> <p>Button to UpgradeActivity</p> <p>UPGRADEACTIVITY:</p> <p>Change vehicle enginelvl Int Button back to MainActivity</p> <p>Main>Upgrades>Upgrade</p> <p>Thank you for your time</p>

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