While philanthropists in China debate whether his theatrical style helps or hinders the growth of philanthropic culture there, Mr. Chen has no doubt about his own significance. His business card describes him as “Most Influential Person of China” and “Most Well-known and Beloved Chinese Role Model.”

On Sunday he met with officials from the New York City Rescue Mission and asked them to supply the homeless people as guests. They said they would participate in the event as long as he did not hand out any cash, said Craig Mayes, the group’s executive director. Mr. Mayes said he was concerned that some of the clients might use the cash to buy alcohol and drugs. In return, Mr. Chen agreed to donate $90,000 to the organization, and the two parties signed a contract.

On Wednesday morning, the boathouse was abuzz with activity. Large security officers in suits were posted around the building. Scores of journalists had descended on the site. The police had set up barricades.

The buses from the rescue mission arrived shortly before noon, and the men and women filed into the boathouse. Tuxedoed waiters standing at the entrance offered them glasses of fruit juice and ice water with lemon. A video extolling the accomplishments of Mr. Chen played on four screens above the dais.

“This is not bad: Central Park, a summer day,” said Frank Oquendo, 48, one of the guests, as he and the others were ushered to their seats at large banquet tables draped in white tablecloths. “Being in here is like being a billionaire for a day.”

Many said they had heard conflicting reports about whether Mr. Chen might distribute cash. “Is it true that they’re going to give us a donation?” asked Roberto Cruz, 40. “I hope they didn’t mislead us.”

As the guests dug into their first course — sesame-crusted tuna with Asian vegetable slaw and lemon grass — a program of music, speeches and even magic tricks unfolded on a dais. Volunteers dressed in Chinese military outfits sang.