Android的代碼 - 拉多姆數生成調用活動

Question

可能重複：
Generating random number in a range with Java
How can I generate random number in specific range in Android?

這裏是我的方案 從在MainActivity;在點擊一個按鈕我想生成一個隨機數從1到4 基於輸出，我想寫一個if-else將調用4個不同的活動

所以點擊時，如果生成4，然後呼叫活動4 下一次1可以生成，並應該呼叫活動1 等等......

有人可以幫我這個代碼嗎？

Answer 1

myBtn.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View v) { 
      // TODO Auto-generated method stub 

      Random r = new Random(); 
      int index = r.nextInt(4)+1; 

      Intent intent; 

      if (index == 4) { 
       intent = new Intent(Activity.this, Activity4.class); 
      } 
      else if (index == 3) { 
       intent = new Intent(Activity.this, Activity3.class); 
      } 
      else if (index == 2) { 
      intent = new Intent(Activity.this, Activity2.class); 
      } 
      else 
      intent = new Intent(Activity.this, Activity1.class);      

      startActivity(intent);     
     } 
    }); 

Answer 2

public void test1(){ 
    Random r = new Random(); 
    int index = r.nextInt(4)+1; 

    Intent intent = null; 

    switch(index){ 
    case 1: intent = new Intent(this, Activity1.class); 
     break; 
    case 2: intent = new Intent(this, Activity2.class); 
     break; 
    case 3: intent = new Intent(this, Activity3.class); 
     break; 
    case 4: intent = new Intent(this, Activity4.class); 
     break; 
    default: 
    Log.e("ERROR", ""); 
      return; 
    } 
    if(intent != null){ 
     this.startActivity(intent); 
    } 
    }