Java 如何在多个活动中包含相同的代码（Android Studio）

我有50项活动。每个活动都会随机打开新活动，如下所示：

public void openNewActivity(View view) {

Random generator = new Random();
int number = generator.nextInt(50) + 1;

Class activity = null; 

switch(number) {
case 1: activity = ActivityNumber1.class; break;
case 2: activity = ActivityNumber2.class; break;
...
case 50: activity = ActivityNumber50.class; break;}

Intent intent = new Intent(this, activity);
    startActivity(intent);

public class Util  
{
  public static Class getRandomActivityClass(){
    Random generator = new Random();
    int number = generator.nextInt(50) + 1;
    Class activity = null; 
    switch(number) {
      case 1: activity = ActivityNumber1.class; break;
      case 2: activity = ActivityNumber2.class; break;
      ...
      case 50: activity = ActivityNumber50.class; break;
   }
   return activity;    
  }
}

现在，我怎样才能只编写一次代码，并将其包含在每个活动中

我已经有了public int，用于保存活动之间要使用的数值：

public class counter_global extends Application...

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将其封装在类中，以便可以根据需要重用：

class NewActivity
{
    static void openRandom()
    {
        // Insert your code here.
    }
}

然后在你的活动中：

NewActivity.openRandom();

---

您应该创建一个全局抽象活动类“MainActivity”，并使每个活动继承该类。因此，任何子活动都将继承您的代码，并且在任何地方都可用

例如：

public abstract class MainActivity extends Activity {
    public void openNewActivity(View view) {

    Random generator = new Random();
        int number = generator.nextInt(50) + 1;

        Class activity = null; 

        switch(number) {
        case 1: activity = ActivityNumber1.class; break;
        case 2: activity = ActivityNumber2.class; break;
        ...
        case 50: activity = ActivityNumber50.class; break;}

        Intent intent = new Intent(this, activity);
        startActivity(intent);
    }
}

还有你的子类活动

public class OwnActivity1 extends MainActivity {


}

---

在您自己的Activity1中，方法“openNewActivity”将可用，您可以在需要的地方调用它。这种方法的主要优点是，如果需要的话，可以在以后一次对所有活动进行更改。例如，您可以在MainActivity上进行更改，在右上角添加一个“参数”按钮，或设置背景色、上下文菜单或操作栏等任何内容。

1-创建如下类：

public void openNewActivity(View view) {

Random generator = new Random();
int number = generator.nextInt(50) + 1;

Class activity = null; 

switch(number) {
case 1: activity = ActivityNumber1.class; break;
case 2: activity = ActivityNumber2.class; break;
...
case 50: activity = ActivityNumber50.class; break;}

Intent intent = new Intent(this, activity);
    startActivity(intent);

public class Util  
{
  public static Class getRandomActivityClass(){
    Random generator = new Random();
    int number = generator.nextInt(50) + 1;
    Class activity = null; 
    switch(number) {
      case 1: activity = ActivityNumber1.class; break;
      case 2: activity = ActivityNumber2.class; break;
      ...
      case 50: activity = ActivityNumber50.class; break;
   }
   return activity;    
  }
}

并在每项活动中使用它：

Intent intent = new Intent(this, Util.getRandomActivityClass());
startActivity(intent);

2-您可以创建基本活动类，将方法置于基础上，并从基类继承活动：

public class BaseActivity extends ActionBarActivity {

   public void runRandomActivityClass(){
    Random generator = new Random();
    int number = generator.nextInt(50) + 1;
    Class activity = null; 
    switch(number) {
      case 1: activity = ActivityNumber1.class; break;
      case 2: activity = ActivityNumber2.class; break;
      ...
      case 50: activity = ActivityNumber50.class; break;
    }

    Intent intent = new Intent(this, activity);
    startActivity(intent); 
  }

}

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50项活动？你能重复使用其中一个而不是创建新的吗？我想它可能更具动态性，但每个活动都有不同的布局和内容。