按鈕重定向 - Android Studio中的登錄活動

Question

了我寫的登錄應用程序中的問題，但finaly我已經得到了應用「偏偏已停止」

也許你能幫什麼是錯的這個問題呢？

package com.example.micha.notes; 
 

 
import android.app.Activity; 
 
import android.content.Intent; 
 
import android.graphics.Color; 
 
import android.os.Bundle; 
 
import android.view.View; 
 

 
import android.widget.Button; 
 
import android.widget.EditText; 
 
import android.widget.TextView; 
 
import android.widget.Toast; 
 

 
public class MainActivity extends Activity { 
 
    Button b1,b2; 
 
    EditText ed1,ed2; 
 

 
    TextView tx1; 
 
    int counter = 3; 
 

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

 
     b1 = (Button)findViewById(R.id.button); 
 
     ed1 = (EditText)findViewById(R.id.editText); 
 
     ed2 = (EditText)findViewById(R.id.editText2); 
 

 
     b2 = (Button)findViewById(R.id.button2); 
 
     tx1 = (TextView)findViewById(R.id.textView3); 
 
     tx1.setVisibility(View.GONE); 
 

 
     b1.setOnClickListener(new View.OnClickListener() { 
 
      @Override 
 
      public void onClick(View v) { 
 
       if(ed1.getText().toString().equals("a") && 
 
         ed2.getText().toString().equals("a")) { 
 
        // Toast.makeText(getApplicationContext(), "Redirecting...", Toast.LENGTH_SHORT).show(); 
 
        Intent toy = new Intent(MainActivity.this, ListActivity.class); 
 
        startActivity(toy); 
 
       }else{ 
 
        Toast.makeText(getApplicationContext(), "Wrong Credentials",Toast.LENGTH_SHORT).show(); 
 

 
          tx1.setVisibility(View.VISIBLE); 
 
        tx1.setBackgroundColor(Color.RED); 
 
        counter--; 
 
        tx1.setText(Integer.toString(counter)); 
 

 
        if (counter == 0) { 
 
         b1.setEnabled(false); 
 
        } 
 
       } 
 
      } 
 
     }); 
 

 
     b2.setOnClickListener(new View.OnClickListener() { 
 
      @Override 
 
      public void onClick(View view) { 
 
       finish(); 
 
      } 
 
     }); 
 
    } 
 
}

我認爲臭蟲是這裏的某個地方，但不知道該怎麼辦:(

public void onClick(View v) { 
 
       if(ed1.getText().toString().equals("a") && 
 
         ed2.getText().toString().equals("a")) { 
 
        // Toast.makeText(getApplicationContext(), "Redirecting...", Toast.LENGTH_SHORT).show(); 
 
        Intent toy = new Intent(MainActivity.this, ListActivity.class); 
 
        startActivity(toy); 
 
       }else{

Answer 1

你加活動清單？

Intent toy = new Intent(MainActivity.this, ListActivity.class); 

ListActivity？

<activity 
     android:name=".ListActivity" 
     android:configChanges="keyboardHidden|orientation|screenSize"/>