XNA Gamestudio - NPCs get stuck at walls and each other (Visual Basic) - visual-studio-2013

Question

I created NPCs that move that direction you're standing at the moment. If they touch something, they never will move again. I don't have a clue and already wasted like 6 hours searching the fault.
That is my Move-Method:
Overrides Sub Move()
Dim actorPosition As Vector2
Dim spieler As Actor
For Each obj As Actor In Actor.ActorList
If TypeOf obj Is Actor And obj.Alive And obj.ObjektTyp = "A"c Then
actorPosition = obj.position
spieler = obj
End If
Next
Dim difPos As Vector2 = position - actorPosition
normaldifpos = difPos
normaldifpos.Normalize()
If lastTimeAttack + intervallBetweenAttack1 < Game1.Game1Time Then
If difPos.Length < range Then
Select Case ObjektTyp
Case "Z"c
spieler.leben -= stärke
Case "H"c
For Each obj As Objekt In ObjList
If TypeOf obj Is Spells Then
If obj.ObjektTyp = "Z"c And obj.Alive = False Then
obj.position = position
obj.richtung = -normaldifpos
obj.senderE = Me
obj.stärke = stärke
obj.Alive = True
Exit For
End If
End If
Next
End Select
lastTimeAttack = Game1.Game1Time
End If
End If
If difPos.Length() < agroRange Then
If spieler IsNot Nothing And Not collide((normaldifpos + New Vector2(-4, -4) * speed)) Then
position = position - normaldifpos * speed
Else
End If
End If
End Sub
And this my collide method:
Public Overridable Function collide(vek As Vector2) As Boolean
Dim extrahitbox As Rectangle
extrahitbox = Hitbox
extrahitbox.X += vek.X
extrahitbox.Y += vek.Y
For Each obj As Objekt In Objekt.ObjList
If TypeOf obj Is Spells Or TypeOf obj Is Key Or TypeOf obj Is PowerUP Or TypeOf obj Is Coin Then
Else
If extrahitbox.Intersects(obj.Hitbox) Then
Return True
End If
End If
Next
For Each Act As Actor In Actor.ActorList
If Act IsNot Me Then
If extrahitbox.Intersects(Act.Hitbox) Then
Return True
Else
End If
End If
Next
If extrahitbox.X < 0 Then
Return True
ElseIf extrahitbox.Right > 1280 Then
Return True
ElseIf extrahitbox.Top < 0 Then
Return True
ElseIf extrahitbox.Bottom > 720 Then
Return True
End If
End Function
I would appreciate help!

Answer 1

From your example it looks object stuck because once when it collide with other object you are not doing any update to position. After determing collision you have to calculate how deep object is inside other object and move it back to previous position.
One way is after you determinate collision you simply negate velocity.
object.Position -= object.Velocity
object.Velocity = new vector2(0,0)
Other way is more accurate as velocity remain same and if your origin is on top-left position. It collision happened, it will position your object right next to other object depend from where collision happened.
If obj.Intersect(otherObj) Then
Dim newPos as new vector2d = obj.Position
if (obj.velocity.x>0) then newPos.x = otherObj.Left - obj.width
if (obj.velocity.x<0) then newPos.x = otherObj.right
obj.Position = newPos
End If
So basicly goes like this
put position to temp varialbe
check collision
if collision happened set original to temp
draw