Why does Sleep(); function skip Label -> Text commands? - winforms

Question

In my Programming I have made two Attack logs (they are labels) which display things that happen during a battle... But whenever I run the code, both labels skip all previous code and display the last thing that It was told to display...
this -> EnemyAttackLog -> Text = "[Enemy Attack Log] " + EName + " Attacked!!";
Sleep(500);
damage = rnd4 -> Next(-2,3) + EnemyA;
if (D > EnemyA)
{
damage = rnd4 -> Next(3,6);
this -> AttackLog -> Text = "[Attack Log] Your Armor Reduced the Damage!";
}
Sleep(500);
this -> EnemyAttackLog -> Text = "[Enemy Attack Log] " + EName + " did " + damage + " Damage";
Hp -= damage;
this -> HealthBar -> Value = Hp;
Sleep(800);
damage = rnd4 -> Next(-2,3) + A;
if (EnemyD > A)
{
damage = rnd4 -> Next(3,6);
this -> EnemyAttackLog -> Text = "[Enemy Attack Log] " + EName + "'s armor reduced damage!";
}
Sleep(1500);
this -> AttackLog -> Text = "[Attack Log] " + Name + " did " + damage + " Damage";
EnemyHp -= damage;
this -> EnemyHealth -> Value = EnemyHp;
If this did what i thought it would do, It would display
this -> EnemyAttackLog -> Text = "[Enemy Attack Log] " + EName + " Attacked!!";
for Half a second and move on to display the next code for Another half a second, But instead, all it does is wait for ALL the sleep functions (Which added together makes 3300 milliseconds) and THEN displays the text at the very end... which is
this -> AttackLog -> Text = "[Attack Log] " + Name + " did " + damage + " Damage";
Why does it skip all previous commands (for the labels text) but STILL waits for 3300 milliseconds?

Answer 1

It is probably down to the fact you are sleeping the UI thread. I've just tried a similar test in C# and I get the same issue. To fix this you will have to call Refresh on the textbox after setting the value.
Another way would be to do the work on a background thread and then marshal the "this->EnemyAttackLog->Text = sometext" code onto the UI thread. This way your UI will stay responsive.