我试图构建Ingenico POS终端(iWL220)的模拟器。
主屏幕我有一个组合框。一旦用户输入id和密码,组合框就会加载6个菜单。如果用户单击btn1,则组合框清除菜单并添加另一组菜单。如果用户单击btn1
以获取新加载的菜单,则再次清除组合框并加载另一组菜单。
我的问题是每次点击按钮(btn1,btn2,btn3,btn4,btn5)我必须编写很多if else语句。实施例;
第一个菜单(在组合框中)有6个扇区。
如果用户选择1.SectorA,则用户单击btn1。然后btn1清除组合框并加载另一组菜单。这个时间菜单(在组合框中)有3家公司。
这次用户选择1.CompanyA然后用户再次点击btn1。然后btn1清除组合框并加载另一组菜单。此时间菜单(在组合框中)有2个付款选项。
现在,如果用户单击btn1或btn2,则可见的组合框变为false,并且在主屏幕中有一个标签和文本框。文本框允许用户输入用户号码并按Enter键(绿色按钮)。
我已经将Ingenico终端图片加载为jpeg和顶部我设置了我的按钮。 我只提供了我的模拟的小版本。在我的应用程序中,用户可以选择114个概率。
在我的应用程序中,btn1有92个被点击的概率,btn2有53个被点击的概率,依此类推。用户输入用户号码并单击绿色按钮后,我的应用程序使用wfc服务格式化数据并发送到sql server。 但是在用户点击按钮的每个组合之前,在我的应用程序中我将btn编号存储为422.这422意味着,用户选择了SectorD + CompanyB + ParitalPayment选项。所以我的wfc会知道它是什么意思422。
我的问题是为这个概率案例构建我的按钮事件的最短路径是什么?
我有4个按钮。 Btn1,Btn2,Btn3和Btn4。我还有一些如下所示的数组和1个组合框。
1.ArrayMain() = {“1.Water”,”2.Air”,”3.Soil”,”4.Fire”}
1.1. ArrayWater() = {“1.Salty”,”2.Fresh”, “3.Contaminated”}
1.1.1.ArraySalty() = {1.”AA”, 2.”BB”, 3.”CC”}
1.1.2.ArrayFresh() = {1.”DD”, 2.”EE”, 3.”FF”}
1.1.3.ArrayContaminated() = {1.”XX”, 2.”YY”, 3.”ZZ”}
1.2 ArrayAir() = {“1.Fresh”, “2.Contaminated”}
1.3 ArraySoil() = {“1.Normal”, “2.Contaminated”}
1.4 ArrayFire() = {“1.Low”,”2.Mid”,”3.High”}
当我的应用程序启动时,第一个数组值1.(ArrayMain)
将填充comboBox。这个组合框将有4个值,其中包括“1.Water”,“2.Air”,“3.Soil”,“4.Fire”。如果用户选择“1.Water”而不是用户点击Btn1。比btn1事件清除comboBox并将1.1ArrayWater()
值加载到comboBox。
第二次如果用户选择“1.Salty”而不是用户再次点击btn1,这次btn1事件清除comboBox并将1.1.1ArraySalty()
值加载到comboBox中。
如果用户选择“2.BB”而不是用户点击Btn2并发送信息“BB”进行计算,则第三次。
首先你有5个(或多或少)菜单项,每次按下任何(数字)按钮(在pos终端中1到9 lilke),屏幕上会出现新菜单。
答案 0 :(得分:3)
任何特定时间的每个按钮都应根据系统状态执行一些特定操作。显然,如果您尝试根据众多不同变量决定具体操作,您将创建大量分支代码。这样的代码很难正确编写,甚至更难以调试和维护。
那么,如果我们在某个特定的类(接口)中封装每个可能状态(状态序列)的当前操作,该怎么办:
/// <summary>
/// Represents internal terminal presenter that is used inside IGlobalTerminalPresenter.
/// </summary>
public interface ITerminalPresenter
{
void UpdateUI();
ITerminalPresenter this[Int32 index]
{
get;
}
ITerminalPresenter Do1();
ITerminalPresenter Do2();
ITerminalPresenter Parent
{
get;
set;
}
void Reset();
}
在表单中,我们将使用类似接口的字段来封装演示者的所有更改。
/// <summary>
/// Represents terminal presenter that UI can operate upon.
/// </summary>
public interface IGlobalTerminalPresenter
{
void UpdateUI();
void Do1();
void Do2();
Int32 SelectedIndex
{
get;
set;
}
void Reset();
}
我们的事件处理程序将成为:
private void comboBox_SelectedIndexChanged(object sender, EventArgs e)
{
var senderComboBox = (ComboBox)sender;
this.globalTerminalPresenter.SelectedIndex = senderComboBox.SelectedIndex;
}
private void button1_Click(object sender, EventArgs e)
{
this.globalTerminalPresenter.Do1();
}
private void button2_Click(object sender, EventArgs e)
{
this.globalTerminalPresenter.Do2();
}
为了让我们的具体TerminalPresenters与表单进行互操作,我们将强制我们的表单实现以下接口:
/// <summary>
/// This represents your UI in technology-independent manner
/// </summary>
public interface ITerminalView
{
String Title { get; set; }
String Input { get; set; }
String Output { get; set; }
String Button1_Text { get; set; }
String Button2_Text { get; set; }
IEnumerable<String> SelectionItems { get; set; }
void Clear();
}
public partial class MainForm : Form,
ITerminalView
{
...
#region ITerminalView implementation
public string Title
{
get { return this.Text; }
set { this.Text = value; }
}
public String Button1_Text
{
get { return this.button1.Text; }
set { this.button1.Text = value; }
}
public String Button2_Text
{
get { return this.button2.Text; }
set { this.button2.Text = value; }
}
public string Input
{
get { return this.textBox_Input.Text; }
set { this.textBox_Input.Text = value; }
}
public string Output
{
get { return this.textBox_Output.Text; }
set { this.textBox_Output.Text = value; }
}
public IEnumerable<string> SelectionItems
{
get { return this.comboBox.Items.Cast<String>(); }
set
{
this.comboBox.Items.Clear();
if (value == null)
return;
foreach (var item in value)
{
this.comboBox.Items.Add(item);
}
}
}
public void Clear()
{
this.comboBox.SelectedIndex = -1;
this.Title = String.Empty;
this.Input = String.Empty;
this.Output = String.Empty;
this.SelectionItems = null;
}
#endregion
现在我们将创建两个TerminalPresenters - 一个只允许通过组合框选择下一个选项,一个计算两个数字的总和。它们都使用相同的基类。
/// <summary>
/// Base class for all presenters
/// </summary>
public abstract class TerminalPresenterBase : ITerminalPresenter
{
protected ITerminalView view;
public TerminalPresenterBase(ITerminalView view)
{
if (view == null)
throw new ArgumentNullException("view");
this.view = view;
this.Parent = this;
}
public abstract void UpdateUI();
public abstract ITerminalPresenter this[int index]
{
get;
}
public abstract ITerminalPresenter Do1();
public abstract ITerminalPresenter Do2();
public virtual ITerminalPresenter Parent
{
get;
set;
}
public virtual void Reset()
{
this.UpdateUI();
}
}
/// <summary>
/// Presenter whose sole goal is to allow user to select some other option and press next
/// </summary>
public class SelectOptionPresenter : TerminalPresenterBase
{
private IList<KeyValuePair<String, ITerminalPresenter>> options;
private ITerminalPresenter selected;
private String title;
public SelectOptionPresenter(ITerminalView view,
String title,
IList<KeyValuePair<String, ITerminalPresenter>> options)
: base(view)
{
if (options == null)
throw new ArgumentNullException("options");
this.title = title;
this.options = options;
foreach (var item in options)
{
item.Value.Parent = this;
}
}
public override void UpdateUI()
{
this.view.Clear();
this.view.Button1_Text = "Confirm selection";
this.view.Button2_Text = "Go back";
this.view.Title = title;
this.view.SelectionItems = options
.Select(opt => opt.Key);
}
public override ITerminalPresenter this[int index]
{
get
{
this.selected = this.options[index].Value;
return this;
}
}
public override ITerminalPresenter Do1()
{
return this.ConfirmSelection();
}
public override ITerminalPresenter Do2()
{
return this.GoBack();
}
public ITerminalPresenter ConfirmSelection()
{
this.selected.UpdateUI();
return this.selected;
}
public ITerminalPresenter GoBack()
{
this.Parent.UpdateUI();
return this.Parent;
}
}
public enum APlusBState
{
EnterA,
EnterB,
Result
}
public class StepActions
{
public Action UpdateUI { get; set; }
public Func<ITerminalPresenter> Do1 { get; set; }
public Func<ITerminalPresenter> Do2 { get; set; }
}
public class APlusBPresenter : TerminalPresenterBase
{
private Int32 a, b;
private APlusBState state;
private String error = null;
private Dictionary<APlusBState, StepActions> stateActions;
private void InitializeStateActions()
{
this.stateActions = new Dictionary<APlusBState, StepActions>();
this.stateActions.Add(APlusBState.EnterA,
new StepActions()
{
UpdateUI = () =>
{
this.view.Title = this.error ?? "Enter A";
this.view.Input = this.a.ToString();
this.view.Button1_Text = "Confirm A";
this.view.Button2_Text = "Exit";
},
Do1 = () => // Confirm A
{
if (!Int32.TryParse(this.view.Input, out this.a))
{
this.error = "A is in incorrect format. Enter A again";
return this;
}
this.error = null;
this.state = APlusBState.EnterB;
return this;
},
Do2 = () => // Exit
{
this.Reset();
return this.Parent;
}
});
this.stateActions.Add(APlusBState.EnterB,
new StepActions()
{
UpdateUI = () =>
{
this.view.Title = this.error ?? "Enter B";
this.view.Input = this.b.ToString();
this.view.Button1_Text = "Confirm B";
this.view.Button2_Text = "Back to A";
},
Do1 = () => // Confirm B
{
if (!Int32.TryParse(this.view.Input, out this.b))
{
this.error = "B is in incorrect format. Enter B again";
return this;
}
this.error = null;
this.state = APlusBState.Result;
return this;
},
Do2 = () => // Back to a
{
this.state = APlusBState.EnterA;
return this;
}
});
this.stateActions.Add(APlusBState.Result,
new StepActions()
{
UpdateUI = () =>
{
this.view.Title = String.Format("The result of {0} + {1}", this.a, this.b);
this.view.Output = (this.a + this.b).ToString();
this.view.Button1_Text = "Exit";
this.view.Button2_Text = "Back";
},
Do1 = () => // Exit
{
this.Reset();
return this.Parent;
},
Do2 = () => // Back to B
{
this.state = APlusBState.EnterB;
return this;
}
});
}
public APlusBPresenter(ITerminalView view) : base(view)
{
this.InitializeStateActions();
this.Reset();
}
public override void UpdateUI()
{
this.view.Clear();
this.stateActions[this.state].UpdateUI();
}
public override ITerminalPresenter this[int index]
{
get { throw new NotImplementedException(); }
}
public override ITerminalPresenter Do1()
{
var nextPresenter = this.stateActions[this.state].Do1();
nextPresenter.UpdateUI();
return nextPresenter;
}
public override ITerminalPresenter Do2()
{
var nextPresenter = this.stateActions[this.state].Do2();
nextPresenter.UpdateUI();
return nextPresenter;
}
public override void Reset()
{
this.state = APlusBState.EnterA;
this.a = 0;
this.b = 0;
this.error = null;
}
}
/// <summary>
/// Represents terminal presenter to use inside GUI. It handles current ISpecificTerminalPresenter inside itself.
/// </summary>
public class GlobalTerminalPresenter : IGlobalTerminalPresenter
{
#region Fields
private ITerminalPresenter current;
private Int32 selectedIndex;
#endregion
#region Constructors
public GlobalTerminalPresenter(ITerminalPresenter mainPresenter)
{
if (mainPresenter == null)
throw new ArgumentNullException("mainPresenter");
this.current = mainPresenter;
this.UpdateUI();
}
#endregion
public void UpdateUI()
{
this.current.UpdateUI();
}
public void Do1()
{
this.current = this.current.Do1();
}
public void Do2()
{
this.current = this.current.Do2();
}
public Int32 SelectedIndex
{
get
{
return this.selectedIndex;
}
set
{
this.selectedIndex = value;
if (value == -1)
return;
this.current = this.current[value];
}
}
public void Reset()
{
this.current.Reset();
}
}
然后我们在表单的构造函数中初始化它们:
public partial class MainForm : Form,
ITerminalView
{
private IGlobalTerminalPresenter globalTerminalPresenter;
public MainForm()
{
InitializeComponent();
var nextLevelPresenters = new KeyValuePair<String, ITerminalPresenter>[]
{
new KeyValuePair<String, ITerminalPresenter>(
"A plus B",
new APlusBPresenter(this)),
new KeyValuePair<String, ITerminalPresenter>(
"Just empty selector",
new SelectOptionPresenter(this,
"Selector with no selection choices",
Enumerable
.Empty<KeyValuePair<String, ITerminalPresenter>>()
.ToArray()))
};
var topPresenter = new SelectOptionPresenter(this, "Select the option and press the confirm button", nextLevelPresenters);
this.globalTerminalPresenter = new GlobalTerminalPresenter(topPresenter);
}
P.S.1:这些代码片段假设您有一个名为MainForm的表单,它有两个按钮 - button1,button2,一个组合框,两个textBoxes - textBox_Input,textBox_Output。
P.S.2:使用的模式足够接近Model-View-Presenter,只有DataBindings。
P.S.3 如果修改APlusBPresenter
代码,则可以创建更多或更少的通用状态机Presenters。或者尝试塑造ChainXxxx...
类和接口。
P.S.4:抱歉这些代码墙。对于[SO]格式来说,这可能太多了,所以我在GitHub上提供了特定的概念证明 - https://github.com/Podskal/StackOverflow_29870164.git。它在很多方面都很丑陋,但事实上,它至少可以提供关于如何实现自己的系统的一些想法。
P.S.5:此代码中存在许多有问题的地方,因此您应该仔细考虑如何从中构建自己的系统。