esqueminha pseudo java/C#

main.cs

class ApiClient {	
	private string connectionString;
	
	ctor(String connectionString) {
		this.connectionString = connectionString;
	}
	
	public string FazAlgumaCoisa(string parametros) {
		using (var conexao = new ConexaoComDb(connectionString)) {
			return conexao.PegaDados(parametros);
		}
	}
}

class Business {
	private ApiClient apiclient;
	
	ctor(ApiClient apiclient) {
		this.apiClient = apiclient;
	}
	
	public bool LeEImprime(string parametros) {
		try {
			//valida parâmetros
			if (string.IsNullOrWhiteSpace(parametros)) return false;
			
			var result = apiclient.FazAlgumaCoisa(parametros);
			if (result != null) {
				ChamaImpressora();
				return true;	
			}
			return false;
			
		}
		catch {
			return false;
		}
	}
}

public class FormPrincipal {
	private Business business;
	
	ctor(Business business) {
		this.business = business;
	}
	
	public void ButtonClickHandler(object sender, EventArgs args) {
		var parametros = textBox1.Text;
		var result = business.LeEImprime(parametros);
		if (result == true) {
			ShowMessage("Função executada com sucesso.");
		}
	}
	
}


class Program {
	public static void main() {
		var connectionString = LerConfiguration["ConnectionString"];
		var apiclient = new ApiClient(connectionString);
		var business = new Business(apiclient);
		var formprincipal = new FormPrincipal(business);
		formprincipal.Show();
	}	
}