Exercises and solutions for the fourth day.
Write a small Windows Forms application that consists of two windows (forms). The first (main) window should have a ComboBox with two values, "blocking" and "non-blocking", a Button and an empty Label.
The second window should have a TextBox and two Button controls, one with the text being "OK" and another one with the text being "Cancel".
Pressing the button in the main window should open the second window. If the value "blocking" has been selected from the ComboBox control, then the ShowDialog() method should be picked, otherwise the Show() method is the way to go.
The second window should be closed on pressing one of the buttons. The difference between the two buttons is, however, that the OK button does also "transmit" the value in textbox to the label of the main window.
Place a variety of controls on a Form and display some of the information you can read out using the Environment class like the current username and the current directory.
Write a Windows Forms application that measures the reaction speed using the classes Random, Timer and Stopwatch. The Timer can be placed per drag and drop on the Form as a control.
First you use a random number to determine the value for the timer (when to display a label, that the button can now be pressed). Then, when the timer is firing it's elapsed event, start a new stopwatch measurement. Once the user presses the button the stopwatch should be stopped and the reaction time should be displayed.
Start by using the following LINQ query:
var random = new Random();
var list = Enumerable.Range(0, 100).Select(m => random.Next(0, 1000)).ToArray();
Create now a set of new variables based on the variable list. In total create the following variables with LINQ:
- Find the minimum element min in list.
- Find the maximum element max in list.
- Save the ordered array as a
List<int>in ordered. - Save all odd elements of list in onlyodd.
- Take only the 10 elements after the first 15 elements and save them as an array in elements.
- Take the first element that is bigger than 999 and save it in hulk.
Create a custom user control that contains a Timer control and a Label control as well as a Button. The user control should be a simple implementation of a timer app:
- Show the button with the text "Start" and the label with a time indicator (e.g. "Timer: 00m : 00s").
- When the button is pressed the time string on the label should count upwards.
- The button should be named "Stop" now.
- When the button is pressed the timer stops counting.
- The button should now display "Reset". If it is being pressed, the initial state should be shown again.
Similarly, one could also implement a countdown user control.
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