android - Error:(10) Error parsing XML: duplicate attribute

hi i have got a problem when i was making a navigation drawer.
it show me two :

"Error parsing XML: duplicate attribute"

one of them is about my main layout and another is about my

E:\MyApplication\app\build\intermediates\res\merged\debug\layout\main.xml

and in the down of this two error that show me this:

"Error:Execution failed for task ':app:processDebugResources'.
com.android.ide.common.process.ProcessException: Failed to execute aapt" error too.

and in the preview that say me i have two render error with these subjects

"compilation errors"
and
"Missing classes"

and this is my Main Activity:

     package com.example.mehrad.myapplication;


     import android.content.Context;
     import android.content.SharedPreferences;
     import android.support.v4.widget.DrawerLayout;
     import android.support.v7.app.AppCompatActivity;
     import android.os.Bundle;
     import android.support.v7.widget.LinearLayoutManager;
     import android.support.v7.widget.RecyclerView;
     import android.view.LayoutInflater;


     public class MainActivity extends AppCompatActivity {
         private SharedPreferences sharedPreferences;
         private DrawerLayout drawerLayout;
         private NavigationView navigationView;
         @Override
         protected void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
             setContentView(R.layout.main);
             new MyShared(this);
             new Names("first one");

             new Names("second one");
             RecyclerView recyclerView=(RecyclerView)findViewById(R.id.rec);
             LinearLayoutManager linearLayoutManager=new           
        LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
             recyclerView.setLayoutManager(linearLayoutManager);
             MyAdapter myAdapter=new MyAdapter(this);
             recyclerView.setAdapter(myAdapter);
             drawerLayout =(DrawerLayout) findViewById(R.id.dl);
             navigationView=(NavigationView)findViewById(R.id.nv);
         }

     }

and this is my main layout:

     
                   xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:app="http://schemas.android.com/apk/res-auto"

            android:id="@+id/dl"
            android:fitsSystemWindows="true"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            xmlns:app="http://schemas.android.com/apk/res-auto">
            
                        android:layout_width="wrap_content"      
            android:layout_gravity="right"    
            android:id="@+id/nv"

            app:headerLayout="@layout/header"
            app:menu="@menu/menu"
            android:layout_height="match_parent"/>

    

and this is my Activity main:

     

              xmlns:tools="http://schemas.android.com/tools"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         tools:context="com.example.mehrad.myapplication.MainActivity">

              android:id="@+id/rec"
         android:layout_width="match_parent"
         android:layout_height="match_parent"

         android:clipToPadding="false" />
     

and this is my app file:

     apply plugin: 'com.android.application'

 android {
         compileSdkVersion 25

         buildToolsVersion "25.0.2"
         defaultConfig {
             applicationId "com.example.mehrad.myapplication"
             minSdkVersion 15
             targetSdkVersion 25
             versionCode 1
             versionName "1.0"
             testInstrumentationRunner      
    "android.support.test.runner.AndroidJUnitRunner"
         }

         buildTypes {
             release {
                 minifyEnabled false
                 proguardFiles getDefaultProguardFile('proguard-android.txt'),           
     'proguard-rules.pro'
         }
     }
 }

 dependencies {

     compile fileTree(dir: 'libs', include: ['*.jar'])
     androidTestCompile('com.android.support.test.espresso:espresso-     
core:2.2.2',                   {
       exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:recyclerview-v7:25.3.1'
    compile 'com.android.support:cardview-v7:25.3.1'
}

this is my header:

            android:orientation="vertical" android:layout_width="match_parent"
        android:layout_height="match_parent">
                    android:layout_width="match_parent"

            android:src="@drawable/header"
            android:id="@+id/image"
            android:layout_height="220dp" />
    

and this is my menu:

help me please

Answer

In this block in your main.xml layout:

        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/dl"
        android:fitsSystemWindows="true"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto">

You have the attribute xmlns:app twice (see the bottom line). Remove this duplicate attribute and your app should build fine, i.e.

        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/dl"
        android:fitsSystemWindows="true"
        android:layout_width="wrap_content"
        android:layout_height="match_parent">