When Joe Manganiello first visited LaBare, the Dallas male strip club, in 2012, most of the dancers had no idea who he was.

Few of them watched “True Blood,” the HBO series on which Manganiello plays a beefy werewolf named Alcide. While almost all of the dancers had seen Steven Soderbergh’s male stripper opus “Magic Mike,” in which Manganiello plays a dancer, their knowledge of the cast did not extend beyond the two stars, Channing Tatum and Matthew McConaughey.

“Joe’s brother, Nick, asked me, ‘Have you watched “True Blood?” ’ and I was like, ‘That show is terrible,’ ” recalled Jerred Fulbright, 30, who dances at LaBare under the stage name, J.D. “Joe was standing right next to me when I said that.”

Manganiello took the criticism in stride. He was there, after all, to win the trust of the dancers in the hopes of putting their stories on film. “Magic Mike,” he believed, had scratched only the surface of a fascinating subject — the mostly straight male dancers who perform each night at strip clubs around the country. He persuaded the LaBare dancers to allow him to film and interview them for eight days in December 2012 and July 2013.

“No one had ever given a fly-on-the-wall look at this world,” Manganiello said. “To think that I could stumble on this desert island that wasn’t recorded on any map was mind-blowing to me.”

The resulting documentary, “La Bare,” premiered in January at the Slamdance Film Festival, and will open in Dallas, Los Angeles and New York on Friday.

Manganiello, who had not previously directed a film, first learned about LaBare while researching his part in “Magic Mike.” A friend who had danced at the club in the 1990s assured Manganiello that many of the stereotypes associated with male strippers — that they were gay or troubled young men with substance abuse problems — were untrue.

Working with his brother, Nick, with whom he produced the film, Manganiello initially planned to pitch “La Bare” as a reality television series. But he was persuaded to make a documentary film after he showed 15 minutes of footage to Soderbergh and Elvis Mitchell, the film critic.

“They both said, ‘Don’t give it away to a production company. Finish it yourself, because there’s something really good here,’ ” Manganiello recalled.

As portrayed in the film, the club — which opened in 1978 — is less a seamy den of iniquity and closeted homosexuality than an inviting cabaret populated by earnest, hard-working, straight men who rarely end up wanting for female companionship. Although Manganiello devotes a stretch of the film to the death of Ruben Riguero, a dancer shot during a dispute in the parking lot of a female strip club down the road in 2012, he mostly maintains an upbeat tone and allows the dancers to talk about what drew them to the profession and — in at least one case — has kept them stripping for decades. (The troupe’s unofficial godfather, and the film’s most colorful character is Randy Ricks, known as Master Blaster, who first started dancing at LaBare in 1979 and is now in his 50s.)

Fulbright — who first got into stripping after seeing “Magic Mike,” and who admits to being a “terrible dancer” on camera — said the film accurately captures the club’s camaraderie and the day-to-day life of a dancer. But he does not expect the movie will earn much in the way of respect for the club or the performers of his profession, who despite being adored by female fans are mocked by many men.

“In terms of us trying to grow and get out of the shadows, I don’t really think anything has changed,” Fulbright said. He added that he does not believe the men who “run society down here in Dallas” will watch “La Bare.”

Nevertheless, the subject of male stripping appears to have captured the cultural imagination. In addition to “La Bare,” the television network E! recently aired “Men of the Strip,” a reality television special, and a sequel to “Magic Mike” is scheduled to be filmed this fall. (Manganiello is set to reprise his part.)

David Greven, a professor of English at the University of South Carolina, who has written extensively about gender and sexuality in film, argued that the male stripper has become “a useful figure for a postgay and postfeminist world.”

“Male bodies can be sexually objectified and consumed” by both gay men and female consumers, he said. “But the heterosexual integrity and identity of the male stripper stays resolutely intact and unquestioned.” (That’s probably particularly true for clubs like LaBare, where male patrons are allowed only when accompanied by women.)

Manganiello, who is still weighing whether to spin the “La Bare” documentary into a reality television series, views the trend in more explicitly commercial terms.

“There was ‘True Blood,’ there was ‘Fifty Shades of Grey,’ and all of a sudden women’s sexuality was being talked about, and it was O.K. for women to speak about it publicly,” he said. “And then ‘Magic Mike’ hit theaters, and now you’ve got a market that’s just opened up, and people want more.”