Mayor Marion Barry yesterday announced a program of workshops and seminars to involve District residents in monitoring city services -- the latest in a series of actions aimed at changing the style of his slumping and often embattled administration.

Six months ago, Barry rarely ventured outside the District Building. When he did, he was often attacked for measures he took in his attempt to handle the city's budget crisis, including cutbacks in services and layoffs of more than 1,000 city workers.

"It was necessary to stay out of the community, because the reaction was so bad," said one Barry aide who asked not to be named. The aide said the most vitriolic community response seemed to stem from the layoffs. "Even if people hadn't been laid off themselves, they knew somebody who was."

But now, aides say, Barry believes he has isolated himself from the public and must emerge as a more visible leader. The mayor's advisers say he believes that the unpopular budget decisions are behind him and that the administration which began with such optimism can now get "back on the track."

This new stance goes along with what a Barry aide called the "general assumption" that Barry intends to run for reelection in 1982.

Barry has sent out 10,000 invitations for the March 25 workshops he announced yesterday, and aides expect that at least 800 persons will attend. The workshops will be followed in six months by seminars to evaluate the city's progress in meeting the concerns of citizens.

The workshops point to an evolving mayoral style that includes increased involvement of community leaders, tougher rhetoric on issues such as crime and the condition of the D.C. public schools, and a new reluctance to Barry to comment on some controversial matters on grounds that they fall within the normal, day-to-day operation of the city and are the province of the city administrator.

A Washington Post poll taken in December found that fewer than three of five respondents who said they voted for Barry in 1978 would do so again, with Barry scoring seventh out of eight local public figures in a test of overall popularity.

Four of every 10 persons polled gave Barry an unfavorable job rating at the midpoint of his four-year term, and in many key areas of city services, more persons saw decline than improvement.

Last week, about 75 neighborhood leaders trekked to the Municipal Center at Barry's invitation to hear him announce a new program designed to attack crime in the District. Anita Bonds, a Barry special assistant who was a key aide in his successful 1978 campaign, is coordinating a series of other Barry appearances before neighborhood groups such as parent-teacher associations.

Barry said yesterday that he will spend the entire day at the upcoming workshops at Dunbar High School and will deliver a speech during the lunch break. The 25 workshops will comprise discussion of a number of issues, including neighborhood business development, crime, transportation and services for senior citizens.

"We've not done as good a job as we should have in letting people know what the administration has accomplished," one of the mayor's assistants said. "But now we're not bogged down in the budget problems, and he can get out into the community.That's his arena, no question about it."

With the new emphasis on community involvement has come a change in the mayor's rhetoric, especially on issues such as crime.

Last year, Barry told audiences around the city that there was little he could do to eradicate crime, since much of the increase in the city's crime rate was related to the influx of drugs and factors such as unemployment, which, he contended, the District was virtually powerless to affect. Some civic leaders criticized that approach, saying they believed that citizens wanted to hear a more upbeat prognosis for the fight against crime.

Now Barry tells listeners -- as he told the crowd at the announcement of his crime program -- that his administration "will not tolerate" crime.

He called his crime package "the most comprehensive . . . ever developed for the District of Columbia," although he acknowledged that it consisted principally of expanding or restructuring existing programs, had no firm budget and would not produce immediate results.

At the same time, Barry has begun to decline comment on a wide range of issues, letting press aide Alan Grip or other officials answer reporters' questions.

City Administrator Elijah B. Rogers is now charged with giving public comment on the budget and nearly all other actions of District agencies under his control, except those mostly positive announcements that are saved for the mayor's regular monthly press conferences.