안타깝게도 앱이 중지되었습니다. 나는 mainActivity 클래스

Question

![error ][1] 

package com.welcome.testingnew; 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.R; 

public class MainActivity extends Activity { 

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

     final EditText username; 
     final EditText password; 
     username=(EditText) findViewById(R.id.EditText1); 
     password=(EditText) findViewById(R.id.EditText2); 
     final EditText result=(EditText) findViewById(R.id.EditText3); 
     Button login=(Button) findViewById(R.id.button1); 
     login.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
      if(username.toString().equals("thamarai") && password.toString().equals("selva")){ 
       EditText3.setText("Success"); 


      } 
      else 
       EditText3.setText("failed"); 
      } 
     }); 
    } 





} 

시도에 약간의 코딩을 삽입하려고하면 내가 다음 코드로 projetc 실행하면 작동 잘

public class MainActivity extends Activity { 

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

와 나는

setContentView(R.layout.activity_main); 

같은 후 anycode를 삽입하는 경우 이

 public class MainActivity extends Activity { 

      @Override 
      public void onCreate(Bundle savedInstanceState) { 
       super.onCreate(savedInstanceState); 
       setContentView(R.layout.activity_main); 
final EditText username; 
      final EditText password; 
      username=(EditText) findViewById(R.id.EditText1); 
      password=(EditText) findViewById(R.id.EditText2); 
      final EditText result=(EditText) findViewById(R.id.EditText3); 
      Button login=(Button) findViewById(R.id.button1); } 
     } 

불행히도 app ha s 중지 된 문제는 가능한 한 빨리 답변 해주세요

Answer 1

나는 이것을 달성하려고 노력하고 있습니다. 여기에 작업 코드입니다 :

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" > 

<TextView 
    android:id="@+id/textView1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentTop="true" 
    android:layout_marginTop="28dp" 
    android:text="Username" 
    android:textAppearance="?android:attr/textAppearanceMedium" /> 

<TextView 
    android:id="@+id/textView2" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignRight="@+id/textView1" 
    android:layout_below="@+id/textView1" 
    android:layout_marginTop="30dp" 
    android:text="Password" 
    android:textAppearance="?android:attr/textAppearanceMedium" /> 

<EditText 
    android:id="@+id/editText1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBaseline="@+id/textView1" 
    android:layout_alignBottom="@+id/textView1" 
    android:layout_alignParentRight="true" 
    android:layout_marginLeft="28dp" 
    android:layout_toRightOf="@+id/textView1" 
    android:inputType="textPersonName" > 

    <requestFocus /> 
</EditText> 

<EditText 
    android:id="@+id/editText2" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBottom="@+id/textView2" 
    android:layout_alignLeft="@+id/editText1" 
    android:layout_alignRight="@+id/editText1" 
    android:inputType="textPassword" /> 

<Button 
    android:id="@+id/button1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@+id/textView2" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="34dp" 
    android:text="Login" /> 

<TextView 
    android:id="@+id/textView3" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@+id/button1" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="76dp" 
    android:text="Status" 
    android:textAppearance="?android:attr/textAppearanceLarge" /> 

MainActivity.java

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 

public class MainActivity extends Activity { 

    EditText username; 
    EditText password; 
    TextView status; 

    Button log; 

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

     username = (EditText) findViewById(R.id.editText1); 
     password = (EditText) findViewById(R.id.editText2); 

     status = (TextView) findViewById(R.id.textView3); 

     log = (Button) findViewById(R.id.button1); 
     log.setOnClickListener(new OnClickListener() { 


      @Override 
      public void onClick(View arg0) { 

      String uname = username.getText().toString(); 
      String pass = password.getText().toString(); 

      if(uname.equals("admin") && pass.equals("admin")) 
      { 
       status.setText("Success"); 
      } 
      else 
      { 
       status.setText("failed"); 
      } 

      } 

     }); 

    } 

} 

응용 프로그램 시작,

검증이 실패

,

때 검증 성공,

는 희망이 도움이!