title: how can set map api key in android studio?
body: <p>I am using Google map in my project, map is opening but not loading. I am new on android studio,I do not know how set map key in android studio,<br>
  Please help me.</p>
  
  <p>manifest file is</p>
  
  <pre><code>     &lt;?xml version="1.0" encoding="utf-8"?&gt;
  </code></pre>
  
  <p>
      </p>
  
  <pre><code>&lt;uses-permission android:name="com.truiton.supportmapfragment.permission.MAPS_RECEIVE" /&gt;
  &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
  &lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /&gt;
  &lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /&gt;
  &lt;uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" /&gt;
  &lt;!--
   The following two permissions are not required to use
   Google Maps Android API v2, but are recommended.
  --&gt;
  &lt;uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /&gt;
  &lt;uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /&gt;
  &lt;application
      android:allowBackup="true"
      android:icon="@drawable/logo"
      android:label="@string/app_name"
      android:supportsRtl="true"
      android:theme="@style/AppTheme" &gt;
  
  
      &lt;activity
          android:name=".activities.SplashScreen"
          android:label="@string/app_name"
          android:theme="@style/AppTheme.NoActionBar" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
      &lt;activity android:name=".activities.MainActivity" /&gt;
      &lt;activity
          android:name=".activities.ForCustomer"
          android:label="@string/title_activity_for_customer"
          android:theme="@style/AppTheme.NoActionBar" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".activities.CustomerSignIn"
          android:label="@string/title_activity_customer_sign_in"
          android:theme="@style/AppTheme.NoActionBar" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".activities.Home"
          android:label="@string/title_activity_home"
          android:theme="@style/AppTheme.NoActionBar" &gt;
      &lt;/activity&gt;
      &lt;activity
          android:name=".activities.RegisterCustomer"
          android:label="@string/title_activity_register_customer"
          android:theme="@style/AppTheme.NoActionBar" &gt;
      &lt;/activity&gt;
      &lt;uses-feature
          android:glEsVersion="0x00020000"
          android:required="true"/&gt;
      &lt;meta-data
          android:name="com.google.android.gms.version"
          android:value="@integer/google_play_services_version" /&gt;
  
      &lt;meta-data android:name="com.google.android.maps.v2.API_KEY" android:value="I_REMOVED"/&gt;
  &lt;/application&gt;
  </code></pre>
  
  <p></p>
  
  <p>xml file using like this</p>
  
  <pre><code>&lt;RelativeLayoutxmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/content_frame"
      android:layout_width="match_parent"
      android:layout_height="match_parent" &gt;
      &lt;RelativeLayout
          android:id="@+id/header"
          android:layout_width="fill_parent"
          android:layout_height="50dp"
          android:background="#1B8AB7"&gt;
  
          &lt;ImageView
              android:id="@+id/menu"
              android:layout_width="40dp"
              android:layout_height="25dp"
              android:src="@drawable/menu"
              android:layout_centerVertical="true"
              android:layout_alignParentLeft="true"
              android:layout_marginLeft="10dp"/&gt;
  
          &lt;RelativeLayout
  
              android:id="@+id/realtivelayout_search_bar"
  
              android:layout_width="250dp"
         android:layout_centerHorizontal="true"
              android:layout_height="30dp"
              android:layout_centerVertical="true"
  
              android:background="@drawable/saerchbarbackground"
  
              &gt;
  
              &lt;ImageView
                  android:id="@+id/btn_searchbar"
                  android:layout_width="35dp"
                  android:layout_height="match_parent"
                  android:layout_alignParentRight="true"
                  android:layout_centerVertical="true"
                  android:src="@drawable/search_btn"
                  android:layout_marginRight="5dp"/&gt;
              &lt;EditText
                  android:layout_marginLeft="5dp"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentLeft="true"
                  android:layout_centerVertical="true"
                  android:id="@+id/edittext_searchbar"
                  android:layout_toLeftOf="@+id/btn_searchbar"
                  android:hint=" search for location"
                  android:singleLine="true"
                  android:textColor="#000000"
                  android:background="#00000000"
                  /&gt;
  
          &lt;/RelativeLayout&gt;
  
      &lt;/RelativeLayout&gt;
  
      &lt;fragment
          android:id="@+id/map"
          android:name="com.google.android.gms.maps.SupportMapFragment"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_below="@+id/header"
  
          /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>I Used map api like you said, but map not loading yet. </p>