Android Question White map, google maps not work.

AddManifestText(
<uses-sdk android:minSdkVersion="5" android:targetSdkVersion="26"/>
<supports-screens android:largeScreens="true" 
    android:normalScreens="true" 
    android:smallScreens="true" 
    android:anyDensity="true"/>)
SetApplicationAttribute(android:icon, "@drawable/icon")
SetApplicationAttribute(android:label, "$LABEL$")
SetApplicationAttribute(android:theme, "@android:style/Theme.Holo.Light")
SetApplicationAttribute(android:largeHeap,"true")
AddApplicationText(
<meta-data
  android:name="com.google.android.geo.API_KEY"
  android:value="AIzaSyDIbmbyuijOgRwYNLIGQjukV29Pc_y9iKs"/>
)

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("lyCollectGPS")
    If MapFragment1.IsGooglePlayServicesAvailable = False Then
        ToastMessageShow("Please install Google Play Services.", True)
      End If
End Sub
Sub MapFragment1_Ready
    gmap = MapFragment1.GetMap
    Starter.rp.CheckAndRequest(Starter.rp.PERMISSION_ACCESS_FINE_LOCATION)
    Wait For Activity_PermissionResult (Permission As String, Result As Boolean)
    gmap.GetUiSettings.MyLocationButtonEnabled=True
    Dim m1 As Marker = gmap.AddMarker(10, 30, "test")
    m1.Snippet = "This is the snippet"
End Sub
Sub Activity_PermissionResult (Permission As String, Result As Boolean)
    If Permission = Starter.rp.PERMISSION_ACCESS_FINE_LOCATION Then
        gmap.MyLocationEnabled = Result
    End If
End Sub