The message on the invitation for the $100-a-person first anniversary fund-raiser for Mayor Marion Barry this week is straight and to the point: four words scrawled in white on a slick black background, resembling street gang graffiti on a ghetto wall. "He can handle it," the invitation reads. The word "can" is underlined.

After one year in office, Barry and the cadre of once-wide-eyed, energetic and idealistic "can-do" rebels who rose to power with him are still determined to prove themselves to the doubters of Washington -- and to themselves, as well.

The hoopla is gone; the honeymoon over. And Marion Barry -- heavier, grayer and having frequently traded his rhetoric about being a round-the-clock civil servant for the relief that an out-of-town vacation brings -- has learned what it's really like to be mayor of the District of Columbia.

One of Barry's strongest campaign indictments of Walter E. Washington was that Washington could not get control of a "bumbling and bungling" District bureaucracy. Barry doesn't control it either -- it bungled his showpiece summer jobs for youth program, for example.

And the system works so slowly that a printed list of Barry's accomplishments during his first year in office was not ready for last week's anniversary celebration.

The District is running out of money. Congress is stingy, and the White House plays hardball politics with its generosity. The press can be tough, the school board stubborn. A federal grand jury is investigating the financial affairs of Barry's former wife and a real estate spinoff of Youth Pride Inc., the black self-help organization that launched his political career.

Marion Barry is an extremely proud and confident man. "I guess some people call this arrogance. But I just like to be good. I've been competitive all my life . . . That's part of the drive. That's part of the internal motor," he once told an interviewer.

So for him, survival and success as mayor have become a personal thing. HIS pride is on the line. HIS reputation is at stake. HIS political career -- the only career he's ever known -- hangs in the balance.

But many blacks feel that a part of their own future is wrapped up in Marion Barry's success as mayor. He is a symbol -- the most visible symbol -- of those blacks who grew up in the '60s, began to achieve status, affluence and power in the '70s, and don't want to lose it in the '80s.

For these people, Barry's success proves that black people -- them -- can do the job without bringing to the black community the kind of embarrassment they saw in Walter Washinton's adminsitration.

Barry has to demonstrate that a black man can run this government; that black people can answer the telephones right; that a black woman can be the budget director (black folks can count, too); that blacks not only can execute nickel-and-dime service contracts, but they also can construct skyscrapers downtown.

How well has he handled it so far?

In a general sense, Barry has set a new tone for government, and generated more activity in the mayor's office and more home town pride.

Throughout the city, from welfare mothers to business executives, there's a feeling that the District government is more responsive than before. But there are many who wonder when the new style will reap new substance.

"It's difficult to determine with all the fanfare and hurrah what's really coming out from down there that will change my life," said Everett Scott of Northeast Washington, president of the D.C. Federation of Civic Associations.

"Barry has not developed a mayoral personality that you can see," said the Rev. A. Knighton Stanley of People's Congregational Church. "What is the philosophy of the Barry administration? I do not know."

During his first year, an overall theme of what Barry wants the city to be like has not emerged. Instead, he has devoted considerable energy and resources to mollifying various special interest groups. He has been many things to many people. The goodies of office have been spread around more widely than in the Washington adminsitration.

There have been new appointments for gays, Hispanics and women, and reappointments for many of the holdovers from the Washington administration. A new breed of managers was brought in to head some departments, but promotions from within of longtime civil servants were also made, to ensure peace in the bureaucracy.

Barry directed much of his housing program at the middle class, but he also spent more than $3 million to renovate worn-out public housing units. He realigned the bureaucracy to reduce waiting time for welfare mothers and businessmen alike.

Barry's black activist background and his aggressive campaign posture would have suggested that he would begin immediately to remake the city and its government in his own image. For years, he had craved real power and had preached about what the city should do for the poor and forgotten.

But since taking office on Jan. 2, 1979, Barry has become a mayor who says his job is first, foremost -- and almost exclusively -- to provide services. His broad visions of social reform are a thing of the past.

"I was naive. Write that down," Barry ordered a reporter during a recent interview, pointing his finger toward the notebook and jerking back his head. "I was idealistic, as all young people ought to be idealistic. I was 20-something years old. Everybody who's that age ought to believe in what I believe in now."

There are still echoes of the past in Barry's speeches. As long as there is one family without a home, one child without education, one youth without a job, one business without profit, there is work to do, he said during one of his anniversary speeches last week.

But away from the crowd, behind the desk where he insists the buck stops, Barry speaks of limits, sounding more and more like other politicians stricken by Proposition 13 fever. The boards will come off only so many vacant houses. Every youth who wants and needs a job will not get one. Better education is necessary, but more money is not the answer, he says.

"I never promised to solve the jobs problem," he said.

"I never promised during my campaign that I would have everybody who wanted a house who now lives in substandard conditions in one during this administration," he also said.

"We have to be very careful about what we promised, and about misleading people in general and black people in particular, because they are very suspicious," Barry said last week.

The lack of money is the biggest obstacle Barry sees to doing more. But he and his bureaucratic irregulars have also encountered many problems that were not covered in How to Run the Government Instead of Criticize It 101.

"One of the frustrations is learning that you never have as much control as you want to," said Ivanhoe Donaldson, Barry's general assistant and principal adviser.

One of the early lessons occurred during the 23-day teachers strike in March. Barry misread the stubbornness of the the school board and the clout of his office. When he brought to bear the power of his office and asked the board's minor league politicians to have it his way, they simply looked him in the face and said no.

As summer neared, Barry rushed headlong to fulfill his campaign promise to provide twice as many summer jobs for youth as Washington had the year before. But he forgot that the bumbling of the city's Labor Department was more far-reaching than the labor director he had removed. The program was bungled. Federal investigators termed it the worst-run in the nation. Congress got angry, and Barry used up some precious good will among some key senators on Capitol Hill.

In still other areas, Barry just never got around to fulfilling campaign promises or found out, once in office, that his campaign stance was incorrect.

He balked, for example, on his campaign pledge to sever health services operations from the troubled Department of Human Resources.

Promises of a citywide conference on education, establishment of a model day-care center to commemorate the "International Year of the Child" and setting up a broad-based citywide task force on public education were not fulfilled. Barry blamed many of his shortcomings in education on a "terrible" school board, and quickly reminded a reporter that his authority over the schools is limited.

"That's not passing the buck?" the reporter asked.

"No," said Barry, "That's a fact."

Barry's new song since taking office is loud enough to suggest to some persons close to him that he is bored, frustrated and disappointed in what he has found the job to be.

"How can you have a vision of the city if you have to be worried about somebody's water meter," said Stanley, who was one of the cochairmen of Barry's first anniversary celebration. "He's not at home in the mayor's chair. He's a broad strokes man. The details are too much. It rubs against the grain of who he is."

But one glance at Barry, sitting back authoritatively in his red leather office chair, strolling broad-shouldered into a hall with a bodyguard by his side, pursing his lips before a verbal battle with a reporter, or sitting in the back of his chauffeured limousine, makes it obvious that Barry very much enjoys being mayor.

At night, his midnight blue sedan with a license tag that reads "MAYOR" races through town, red light flashing, siren squealing, taking Barry to various social, diplomatic and unofficial rendezvous. He tries to make them all.

Barry, who only a few years ago lived in a rented basement apartment, is now co-owner of a 9-year-old, three-bedroom $125,000 house in the up-and-coming "Silver Coast" area of Southeast Washington. He is expanding the living room so he will have more room to entertain. His wife gave up her Volkswagen for a white Cadillac Seville with license tag No. 1. g

And he seems to enjoy traveling. All or part of 75 days of his first year in office were spent out of town: Pittsburgh, Atlanta, Las Vegas and Honolulu on business; Miami, Hilton Head, Woodstock and Jamaica on vacation; and five countries in Africa in 19 days -- courtesy of the U.S. State Department.

Many of the problems he faces as he begins his second year are political, because he came into office with so slim a base that it could only be victorious in a close three-way election like that of the September 1978 primary. He is trying to build a broader base, but the problem of clashing constituencies stands in the way. He will have to take some stands.

He will have to referee and choose sides in a tough fight between the city's business and labor communities over the city's high workers' compensation and disability tax formulas. Barry is a favorite with neither group, and he knows that in this one at least one party may lose.

There are many whites in Barry's political base, a fact that got him labeled "the white community's candidate" during the campaign. Already, as he tries to expand it, many of the city's black ministers whose congregations include many of the regularly voting middle-class blacks are grumbling about his support for legalized gambling and complaining publicly that his strong support for gay rights is encouraging homosexuality in the city.

Barry is trying to keep his campaign promise to place more Hispanics in upper-level government jobs. But each Hispanic hired draws sneers from blacks who feel unfairly passed over when others get the jobs.

And still haunting him is the ghost of Youth Pride Inc., the self-help organization for outcast "street dudes" that Barry helped to found.

Federal prosecutors are investigating reports that three officials in a real estate spinoff of Youth Pride stole, misappropriated and diverted $600,000 from the U.S. government and tenants at the Clifton Terrace apartments in Northwest Washington between 1974 and 1978. Among the three are Mary Treadwell, to whom Barry was married until 1977.

Barry has refused to comment on that issue. "The public's not the grand jury," he said. "When the public wants to know about what happened they ought to go and get on the grand jury . . . When the grand jury calls me, I will speak on it."

He also has said little about the controversy surrounding a $100,000 loan he and his wife Effi received to buy their home. The loan was first made at the preferential rate of 8 3/4 percent, but Barry later had it rewritten at the going rate of 12 percent -- after reporters discovered the discount, which Barry had not disclosed.

Donaldson, Barry's chief political strategist, expects the administration to be hurt politically by the Pride controversy. He also concedes that Barry made a mistake in the way he handled his mortgage. Stephen Koczak, president of the Federation of Citizens Associations of the District of Columbia and a resident of Cleveland Park, agrees.

"The prestige of the mayor has gone down. It has to do with his personal life and things about his style," Koczak said.

Despite studied instructions on how to be "more mayoral," some still consider Barry a diamond in the rough when it comes to proper conduct.

He is still one helluva charmer with the ladies around town. And he laughs off as nothing serious his weekly poker parties. Barry's regular card-playing buddies include "Mr. Bill" -- William B. Fitzgerald, whose savings and loan association gave Barry the loan, on whose board Barry's wife serves and whose directors are part owners of a $143 million project to be built on city-owned land.

"He hasn't acted like a mayor. He still acts like Marion Barry," one City Council member close to Barry said. "You can't be mayor and do those things. If you recognize you're the mayor, you wouldn't do that."

Barry has survived his first year. The city government did not go under, he didn't call anyone on Capitol Hill a rinky-dink and Congress did not revoke "home rule," even though it did for the first time overturn legislation passed by the elected City Council and approved by the mayor.

In fact, many, including some of his former critics, say Barry's rookie year has been a success. But he still feels he is under scrutiny, more than he wants and more than he deserves.

"We're always on trial," he said of himself and other blacks in top roles in city government. "They all put us on trial. You all do. Write that down.You all do," Barry told a reporter.

"Everybody who's a recipient of services in this city is excited about what's going on. It's you and others who are not excited about it.

"If you go out and talk to the people who are the recipients of the services, they're very excited; not happy always, not satisfied -- and shouldn't ever want to be satisfied. But they're excited about what's going on in the government."