While Hitler uses the word "evolution" in Mein Kampf, it is clear that he is not referring to Darwin's theory --- indeed, he never mentions the man. In fact, a look at his writings reveals his sentiments on the subject to be those of an orthodox creationist.
Like a creationist, Hitler asserts fixity of kinds:
The fox remains always a fox, the goose remains a goose, and the tiger will retain the character of a tiger. - Adolf Hitler, Mein Kampf, vol. i, ch. xi
Like a creationist, Hitler claims that God made man:
For it was by the Will of God that men were made of a certain bodily shape, were given their natures and their faculties. - Adolf Hitler, Mein Kampf, vol. ii, ch. x
Like a creationist, Hitler affirms that humans existed "from the very beginning", and could not have evolved from apes:
From where do we get the right to believe, that from the very beginning Man was not what he is today? Looking at Nature tells us, that in the realm of plants and animals changes and developments happen. But nowhere inside a kind shows such a development as the breadth of the jump , as Man must supposedly have made, if he has developed from an ape-like state to what he is today. - Adolf Hitler, Hitler's Tabletalk (Tischgesprache im Fuhrerhauptquartier)
Like a creationist, Hitler believes that man was made in God's image, and in the expulsion from Eden:
Whoever would dare to raise a profane hand against that highest image of God among His creatures would sin against the bountiful Creator of this marvel and would collaborate in the expulsion from Paradise. - Adolf Hitler, Mein Kampf, vol ii, ch. i
Like a creationist, Hitler believes that:
God ... sent [us] into this world with the commission to struggle for our daily bread. - Adolf Hitler, Mein Kampf, vol ii, ch. xiv
Like a creationist, Hitler claims Jesus as his inspiration:
My feeling as a Christian points me to my Lord and Savior as a fighter. It points me to the man who once in loneliness, surrounded only by a few followers, recognized these Jews for what they were and summoned men to fight against them. - Adolf Hitler, speech, April 12 1922, published in My New Order
Like a creationist, Hitler despises secular schooling:
Secular schools can never be tolerated because such schools have no religious instruction, and a general moral instruction without a religious foundation is built on air; consequently, all character training and religion must be derived from faith . . . we need believing people. - Adolf Hitler, Speech, April 26, 1933
Like a creationist, Hitler wished to make prayer compulsory in public schools. Unlike American creationists, he succeeded.
Hitler even goes so far as to claim that Creationism is what sets humans apart from the animals:
The most marvelous proof of the superiority of Man, which puts man ahead of the animals, is the fact that he understands that there must be a Creator. - Adolf Hitler, Hitler's Tabletalk (Tischgesprache im Fuhrerhauptquartier)
So why does he mention evolution at all? On examination, he is talking of differences within species --- of the "micro-evolution" that creationists profess to believe in:
The fox remains always a fox, the goose remains a goose, and the tiger will retain the character of a tiger. The only difference that can exist within the species must be in the various degrees of structural strength and active power, in the intelligence, efficiency, endurance, etc., with which the individual specimens are endowed. (Mein Kampf, vol. i, ch. xi)
So, like a creationist, there is some evolution he is prepared to concede --- evolution within species, which creationists call "microevolution", and which they have no objection to [1]. So it is on the basis of the one part of evolutionary theory which creationists accept that Hitler tried to find a scientific basis for his racism and his program of eugenics.
It is not surprising that Hitler should have found creationist views so attractive. A man who will not admit people of other races to be his brothers is hardly likely to embrace animals of other species as his cousins.