Keep getting red lines under anything I try to find in my layout. How do I fix t

Question

Keep getting red lines under anything I try to find in my layout. How do I fix this? Look for the comments.

MainActivity.java

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;
import android.view.View;
import android.view.View.OnClickListener;

public class MainActivity extends Activity {

   Button button;
  

   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);//this one is fine
       addListenerOnButton();
   }

   public void addListenerOnButton() {

       final Context context = this;

       button = (Button) findViewById(R.id.login);//underneath the word login. red lines under anything being found

                                                                         //by 'find'. Only one that doesn't is main_activity above

       button.setOnClickListener(new OnClickListener() {

           @Override
           public void onClick(View arg0) {

                Intent intent = new Intent(context, Main2Activity.class);
                            startActivity(intent);

           }

       });
      

   }

}

main_activity.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"
    tools:context="edu.rasmussen.mobile.MainActivity" >

    <Button
        android:id="@+id/"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_alignParentTop="true"
        android:text="Login" />

</RelativeLayout>

MainActivity2.java

package edu.rasmussen.mobile;

import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;

public class Main2Activity extends Activity {

   Button button;

   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main_activity2);//red lines under activity_main_activity2
   }

}

activity_main_activity2.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"
    tools:context="edu.rasmussen.mobile.Main2Activity" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

Explanation / Answer

you are missing the import call for classes. do this

import android.R;

import com.yourname.yourapp.R;

Also try cleaning your project.

Step 1: Clean your project by clicking Project -> Clean.

Step 2: Rebuild your project by clicking Project -> Build All.

Related Questions

Navigate

• Browse (All)
• Browse K
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.