使用按鈕觸發時註冊活動崩潰

Question

我創建了一個登錄活動，它是啓動器的活動。我的登錄頁面有兩個按鈕登錄或註冊。註冊按鈕會觸發另一個名爲Main2Activity的活動，這是一個標籤活動，但會一直崩潰。任何幫助，將不勝感激。這裏是Main2Activity：

public class Main2Activity extends AppCompatActivity { 

    private SectionsPagerAdapter mSectionsPagerAdapter; 

    /** 
    * The {@link ViewPager} that will host the section contents. 
    */ 
    private ViewPager mViewPager; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.signup); 

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 
    // Create the adapter that will return a fragment for each of the three 
    // primary sections of the activity. 
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); 

    // Set up the ViewPager with the sections adapter. 
    mViewPager = (ViewPager) findViewById(R.id.container); 
    mViewPager.setAdapter(mSectionsPagerAdapter); 

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs); 
    tabLayout.setupWithViewPager(mViewPager); 

    //Student Sign up button clicked 
    Button StdSignUp = (Button)findViewById(R.id.stdsignup); 
    StdSignUp.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
     Intent HomePage = new Intent(Main2Activity.this,MainActivity.class); 
     startActivity(HomePage); 
     } 
    }); 

    //Teacher Sign up button clicked 
    Button TSignUp = (Button)findViewById(R.id.tsignup); 
    TSignUp.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
     Intent HomePage = new Intent(Main2Activity.this, MainActivity.class); 
     startActivity(HomePage); 
     } 
    }); 


    } 
    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
    } 


    /** 
    * A {@link FragmentPagerAdapter} that returns a fragment corresponding to 
    * one of the sections/tabs/pages. 
    */ 
    public class SectionsPagerAdapter extends FragmentPagerAdapter { 

    public SectionsPagerAdapter(FragmentManager fm) { 
     super(fm); 
    } 

    @Override 
    public Fragment getItem(int position) { 
     switch (position) 
     { 
     case 0: 
      StudentSignup ss = new StudentSignup(); 
      return ss; 
     case 1: 
      TeacherSignup ts = new TeacherSignup(); 
      return ts; 
     default: 
      return null; 
     } 
    } 

    @Override 
    public int getCount() { 
     // Show 3 total pages. 
     return 2; 
    } 

    @Override 
    public CharSequence getPageTitle(int position) { 
     switch (position) { 
     case 0: 
      return "Student Account"; 
     case 1: 
      return "Teacher Account"; 
     } 
     return null; 
    } 
    } 
} 

這裏是在Login Acvivity的onCreate（）方法中觸發Main2Activity的按鈕。

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_login); 

    }); 
    Button mEmailSignUpButton = (Button) findViewById(R.id.Signupbtn); 
    mEmailSignUpButton.setOnClickListener(new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     Intent Signup = new Intent(LoginActivity.this, Main2Activity.class); 
     startActivity(Signup);//this starts sign up page activity named main2activity 
    } 
    }); 
} 

Answer 1

您需要將您的新活動添加到AndroidManifest.xml。例如：

<activity 
     android:name=".Main2Activity" 
     android:label="@string/title_main2_activity"/>