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How to: Create a Flowchart Workflow

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Workflows can be constructed from built-in activities as well as from custom activities. This topic steps through creating a workflow that uses both built-in activities such as the Flowchart activity, and the custom activities from the previous How to: Create an Activity topic. The workflow models a number guessing game.

Note

Each topic in the Getting Started tutorial depends on the previous topics. To complete this topic, you must first complete How to: Create an Activity.

To create the workflow

  1. Right-click NumberGuessWorkflowActivities in Solution Explorer and select Add, New Item.

  2. In the Installed, Common Items node, select Workflow. Select Activity from the Workflow list.

  3. Type FlowchartNumberGuessWorkflow into the Name box and click Add.

  4. Drag a Flowchart activity from the Flowchart section of the Toolbox and drop it onto the Drop activity here label on the workflow design surface.

To create the workflow variables and arguments

  1. Double-click FlowchartNumberGuessWorkflow.xaml in Solution Explorer to display the workflow in the designer, if it is not already displayed.

  2. Click Arguments in the lower-left side of the workflow designer to display the Arguments pane.

  3. Click Create Argument.

  4. Type MaxNumber into the Name box, select In from the Direction drop-down list, select Int32 from the Argument type drop-down list, and then press ENTER to save the argument.

  5. Click Create Argument.

  6. Type Turns into the Name box that is below the newly added MaxNumber argument, select Out from the Direction drop-down list, select Int32 from the Argument type drop-down list, and then press ENTER.

  7. Click Arguments in the lower-left side of the activity designer to close the Arguments pane.

  8. Click Variables in the lower-left side of the workflow designer to display the Variables pane.

  9. Click Create Variable.

    Tip

    If no Create Variable box is displayed, click the Flowchart activity on the workflow designer surface to select it.

  10. Type Guess into the Name box, select Int32 from the Variable type drop-down list, and then press ENTER to save the variable.

  11. Click Create Variable.

  12. Type Target into the Name box, select Int32 from the Variable type drop-down list, and then press ENTER to save the variable.

  13. Click Variables in the lower-left side of the activity designer to close the Variables pane.

To add the workflow activities

  1. Drag an Assign activity from the Primitives section of the Toolbox and hover it over the Start node, which is at the top of the flowchart. When the Assign activity is over the Start node, three triangles will appear around the Start node. Drop the Assign activity on the triangle that is directly below the Start node. This will link the two items together and designates the Assign activity as the first activity in the flowchart.

    Note

    Activities can also be indicated as the starting activity in the workflow by manually linking them activity to the start node. To do this, hover the mouse over the Start node, click one of the rectangles that appear when the mouse is over the Start node, and drag the connecting line down to the desired activity and drop it on one of the rectangles that appear. You can also designate an activity as the starting activity by right-clicking the it and choosing Set as Start Node.

  2. Type Target into the To box and the following expression into the Enter a C# Expression or Enter a VB expression box.

    New System.Random().Next(1, MaxNumber + 1)  

    new System.Random().Next(1, MaxNumber + 1)

    Tip

    If the Toolbox window is not displayed, select Toolbox from the View menu.

  3. Drag a Prompt activity from the NumberGuessWorkflowActivities section of the Toolbox, drop it below the Assign activity from the previous step, and connect the Prompt activity to the Assign activity. There are three ways to connect the two activities. The first way is to connect them as you drop the Prompt activity on the workflow. As you are dragging the Prompt activity to the workflow, hover it over the Assign activity and drop it onto one of the four triangles that appear when the Prompt activity is over the Assign activity. The second way is to drop the Prompt activity onto the workflow at the desired location. Then, hover the mouse over the Assign activity and drag one of the rectangles that appears down to the Prompt activity. Drag the mouse so that the connecting line from the Assign activity connects to one of the rectangles of the Prompt activity, and then release the mouse button. The third way is very similar to the first way, except that instead of dragging the Prompt activity from the Toolbox, you drag it from its location on the workflow design surface, hover it over the Assign activity, and drop it onto one of the triangles that appears.

  4. In the Properties Window for the Prompt activity, type "EnterGuess" including the quotes into the BookmarkName property value box. Type Guess into the Result property value box, and type the following expression into the Text property box.

    "Please enter a number between 1 and " & MaxNumber  

    "Please enter a number between 1 and " + MaxNumber

    Tip

    If the Properties Window is not displayed, select Properties Window from the View menu.

  5. Drag an Assign activity from the Primitives section of the Toolbox and connect it using one of the methods described in the previous step so that it is below the Prompt activity.

  6. Type Turns into the To box and Turns + 1 into the Enter a C# expression or Enter a VB expression box.

  7. Drag a FlowDecision from the Flowchart section of the Toolbox and connect it below the Assign activity. In the Properties Window, type the following expression into the Condition property value box.

    Guess = Target  

    Guess == Target

  8. Drag another FlowDecision activity from the Toolbox and drop it below the first one. Connect the two activities by dragging from the rectangle that is labeled False on the top FlowDecision activity to the rectangle at the top of the second FlowDecision activity.

    Tip

    If you do not see the True and False labels on the FlowDecision, hover the mouse over the FlowDecision.

  9. Click the second FlowDecision activity to select it. In the Properties Window, type the following expression into the Condition property value box.

    Guess < Target

  10. Drag two WriteLine activities from the Primitives section of the Toolbox and drop them so that they are side by side below the two FlowDecision activities. Connect the True action of the bottom FlowDecision activity to the leftmost WriteLine activity, and the False action to the rightmost WriteLine activity.

  11. Click the leftmost WriteLine activity to select it, and type the following expression into the Text property value box in the Properties Window.

    "Your guess is too low."

  12. Connect the WriteLine to the left side of the Prompt activity that is above it.

  13. Click the rightmost WriteLine activity to select it, and type the following expression into the Text property value box in the Properties Window.

    "Your guess is too high."

  14. Connect the WriteLine activity to the right side of the Prompt activity above it.

    The following example illustrates the completed workflow.

    Diagram that shows a completed Windows Workflow Foundation flowchart.

To build the workflow

  1. Press CTRL+SHIFT+B to build the solution.

    For instructions on how to run the workflow, please see the next topic, How to: Run a Workflow. If you have already completed the How to: Run a Workflow step with a different style of workflow and wish to run it using the flowchart workflow from this step, skip ahead to the To build and run the application section of How to: Run a Workflow.

See also