Simple .NET/ASP.NET PDF document editor web control SDK
Listing 8-5. A Simple Form Created in XAML <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:sys="clr-namespace:System;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" > <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="64" /> <ColumnDefinition Width="128" /> <ColumnDefinition Width="128" /> <ColumnDefinition Width="128" /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="24"/> </Grid.RowDefinitions> <Label Grid.Row="0" Grid.Column="0" >Input: </Label> <TextBox Name="input" Grid.Column="1" Text="hello" /> <Label Name="output" Grid.Row="0" Grid.Column="2" ></Label> <Button Name="press" Grid.Column="3" >Press Me</Button> </Grid> </Window> To make this XAML definition of a form useful, you need to do two things. You must load the form s definition and show it to the user, but just doing this will offer no interaction with the user, so the other thing you need to do is make the form interactive. To do this, you use F# to add event handlers to the controls, in this case to add an event handler to the button to place the contents of the textbox into the second label. The function createWindow is a generalpurpose function for loading an XAML form. You then use this function to create the value window, and you pass this value to the form s FindName method to find the controls within the form so you can interact with them. Finally, in the main function you create an instance of the Application class and use this to show the form (see Listing 8-6). Listing 8-6. Displaying the XAML Form and Adding Event Handlers to It #light open System open System.Collections.Generic open System.Windows open System.Windows.Controls open System.Windows.Markup open System.Xml // creates the window and loads the given XAML file into it let createWindow (file : string) = using (XmlReader.Create(file)) (fun stream -> (XamlReader.Load(stream) : > Window))excel vba barcode generator, create barcodes in excel 2010 free, barcode in excel 2007, barcode generator excel 2013 free, how to create a barcode in excel 2007, barcode fonts for excel, open source barcode generator excel, how to add barcode font to excel 2007, excel 2007 barcode formula, barcode checksum excel formula,
// create the window object and add event handler // to the button control let window = let temp = createWindow "Window1.xaml" let press = temp.FindName("press") : > Button let textbox = temp.FindName("input") : > TextBox let label = temp.FindName("output") : > Label press.Click.Add (fun _ -> label.Content <- textbox.Text ) temp // run the application let main() = let app = new Application() app.Run(window) |> ignore [<STAThread>] do main() To get this program to compile, you must add references to PresentationCore.dll, PresentationFramework.dll, and WindowsBase.dll, which are usually found in the directory C:\Program Files\Reference Assemblies\Microsoft\Framework\v3.0. In the other examples in this chapter, you didn t need to add references, since the libraries were automatically referenced by the compiler. The form appears as in Figure 8-11.
The joystick gimbal for the front mount is the same as the back mount joystick. If it s mounted far enough above the NXT, the display and buttons are still accessible. Because the T-56 already makes use of input ports 1 and 3, the swing axis control has to be brought into port 2 and the elevation axis into port 4. The idle position of the joystick is recorded when the program first starts. These raw values are saved in variables C0 and B0, as shown in Figure 6-25. Then the program goes into a long endless loop of moving the two axes and checking whether the jaw should open or close.
Though Web-based, applets still presented many of the issues associated with thick client applications. In the era of the dial-up connection (still far too prevalent even today), downloading the entire code base for a complex applet could take more time than a user was willing to invest. Developers also had to worry about the version of Java present on the client, and some virtual machines left something to be desired.3 Ideally, you just serve up static Web pages after all, that was what the Internet was truly designed to do. Of course, static pages are, well, static, but if you could dynamically generate content on the server and return static content, that would get you somewhere. Within a year of Java being introduced to the world, Sun introduced servlets. No longer would your Java code run in the client browser as with applets; it would run on an application server that you controlled. This would allow developers to leverage existing business applications, and if you needed to upgrade to the latest Java version, you had to worry only about your server. Java s write once, run anywhere nature allowed developers to select best-of-breed application servers and server environments yet another advantage of the new technology. Servlets also served as an alternative to CGI scripts. Servlets were a huge step forward. They offered full access to the entire set of Java application programming interfaces (APIs) and came with a complete library for handling HTTP . However, servlets weren t perfect. Interface design with servlets can be hard. In a typical servlet interaction, you get some information from your user, perform some business logic, and then, using what amounts to print lines, create the HTML to display for the user. Code like that shown in Listing 1-1 was common.
Figure 8-11. A form created using XAML and F#
The control is exactly the same for both axes, as seen in Figures 6-26 and 6-27. The current value of the pot is read and subtracted from the initial position to create a motor power command. The direction of the command is determined by comparing the value to zero. Fortunately, the Motor block doesn t care if the power command is positive or negative; it just uses the size of the number.