[英]What is the best way to clear all controls on a form C#?
I do remember seeing someone ask something along these lines a while ago but I did a search and couldn't find anything. 我记得有一段时间以前看到有人问过这些问题,但是我做了搜索而找不到任何东西。
I'm trying to come up with the cleanest way to clear all the controls on a form back to their defaults (eg, clear textboxes, uncheck checkboxes). 我正在尝试用最干净的方法将表单上的所有控件清除回默认值(例如,清除文本框,取消选中复选框)。
How would you go about this? 你会怎么做?
What I have come up with so far is something like this: 到目前为止我想出的是这样的:
public static class extenstions
{
private static Dictionary<Type, Action<Control>> controldefaults = new Dictionary<Type, Action<Control>>() {
{typeof(TextBox), c => ((TextBox)c).Clear()},
{typeof(CheckBox), c => ((CheckBox)c).Checked = false},
{typeof(ListBox), c => ((ListBox)c).Items.Clear()},
{typeof(RadioButton), c => ((RadioButton)c).Checked = false},
{typeof(GroupBox), c => ((GroupBox)c).Controls.ClearControls()},
{typeof(Panel), c => ((Panel)c).Controls.ClearControls()}
};
private static void FindAndInvoke(Type type, Control control)
{
if (controldefaults.ContainsKey(type)) {
controldefaults[type].Invoke(control);
}
}
public static void ClearControls(this Control.ControlCollection controls)
{
foreach (Control control in controls)
{
FindAndInvoke(control.GetType(), control);
}
}
public static void ClearControls<T>(this Control.ControlCollection controls) where T : class
{
if (!controldefaults.ContainsKey(typeof(T))) return;
foreach (Control control in controls)
{
if (control.GetType().Equals(typeof(T)))
{
FindAndInvoke(typeof(T), control);
}
}
}
}
Now you can just call the extension method ClearControls like this: 现在你可以像这样调用扩展方法ClearControls:
private void button1_Click(object sender, EventArgs e)
{
this.Controls.ClearControls();
}
EDIT: I have just added a generic ClearControls method that will clear all the controls of that type, which can be called like this: 编辑:我刚刚添加了一个通用的ClearControls方法,它将清除该类型的所有控件,可以像这样调用:
this.Controls.ClearControls<TextBox>();
At the moment it will only handle top level controls and won't dig down through groupboxes and panels. 目前它只处理顶级控件,不会通过组框和面板进行挖掘。
I know its an old question but just my 2 cents in. This is a helper class I use for form clearing. 我知道这是一个老问题但只是我的2美分。这是我用于表格清理的帮助类。
using System;
using System.Windows.Forms;
namespace FormClearing
{
class Helper
{
public static void ClearFormControls(Form form)
{
foreach (Control control in form.Controls)
{
if (control is TextBox)
{
TextBox txtbox = (TextBox)control;
txtbox.Text = string.Empty;
}
else if(control is CheckBox)
{
CheckBox chkbox = (CheckBox)control;
chkbox.Checked = false;
}
else if (control is RadioButton)
{
RadioButton rdbtn = (RadioButton)control;
rdbtn.Checked = false;
}
else if (control is DateTimePicker)
{
DateTimePicker dtp = (DateTimePicker)control;
dtp.Value = DateTime.Now;
}
}
}
}
}
And I call the method from any form like this passing a form object as a parameter. 我从任何形式调用方法,将表单对象作为参数传递。
Helper.ClearFormControls(this);
You can extend it for other types of controls. 您可以将其扩展为其他类型的控件。 You just have to cast it. 你只需要施展它。
You can loop for control 你可以循环控制
foreach (Control ctrl in this)
{
if(ctrl is TextBox)
(ctrl as TextBox).Clear();
}
I voted for Nathan's solution, but wanted to add a bit more than a comment can handle. 我投票赞成了Nathan的解决方案,但想补充一点,而不是评论可以处理。
His is actually very good, but I think the best solution would involve sub-classing each of the control types you might be adding before adding them to the GUI. 他实际上非常好,但我认为最好的解决方案是在将它们添加到GUI之前对每个可能添加的控件类型进行子类化。 Have them all implement an interface "Clearable" or something like that (I'm a java programmer, but the concept should be there), then iterate over it as a collection of "Clearable" objects, calling the only method .clear() on each 让他们都实现一个“可清除”或类似的接口(我是一个java程序员,但概念应该在那里),然后迭代它作为“可清除”对象的集合,调用唯一的方法.clear()在每一个上
This is how GUIs really should be done in an OO system. 这就是如何在OO系统中完成GUI。 This will make your code easy to extend in the future--almost too easy, you'll be shocked. 这将使您的代码在将来易于扩展 - 几乎太容易了,您会感到震惊。
Edit: (per Nathan's comment about not changing existing controls) 编辑:(根据内森关于不改变现有控制的评论)
Perhaps you could create "Container" classes that reference your control (one for each type of control). 也许你可以创建引用你的控件的“容器”类(每种类型的控件一个)。 In a loop like the one you set up in your answer, you could instantiate the correct container, place the real control inside the container and store the container in a collection. 在您在答案中设置的循环中,您可以实例化正确的容器,将实际控件放在容器中并将容器存储在集合中。
That way you are back to iterating over a collection. 这样你就可以重新迭代一个集合了。
This would be a good simple solution that isn't much more complex than the one you suggested, but infinitely more expandable. 这将是一个很好的简单解决方案,并不比您建议的解决方案复杂得多,但可扩展性更高。
The above solutions seem to ignore nested controls. 上述解决方案似乎忽略了嵌套控件。
A recursive function may be required such as: 可能需要递归函数,例如:
public void ClearControl(Control control)
{
TextBox tb = control as TextBox;
if (tb != null)
{
tb.Text = String.Empty;
}
// repeat for combobox, listbox, checkbox and any other controls you want to clear
if (control.HasChildren)
{
foreach(Control child in control.Controls)
{
ClearControl(child)
}
}
}
You don't want to just clear the Text property without checking the controls type. 您不希望在不检查控件类型的情况下清除Text属性。
Implementing an interface, such as IClearable (as suggested by Bill K), on a set of derived controls would cut down the length of this function, but require more work on each control. 在一组派生控件上实现诸如IClearable(如Bill K所建议的)之类的接口将减少该函数的长度,但需要对每个控件进行更多的工作。
Here is the same thing that I proposed in my first answer but in VB, until we get VB10 this is the best we can do in VB because it doesn't support non returning functions in lambdas: 这是我在第一个答案中提出的相同的东西,但在VB中,直到我们得到VB10,这是我们在VB中可以做的最好的,因为它不支持lambda中的非返回函数:
VB Solution: VB解决方案:
Public Module Extension
Private Sub ClearTextBox(ByVal T As TextBox)
T.Clear()
End Sub
Private Sub ClearCheckBox(ByVal T As CheckBox)
T.Checked = False
End Sub
Private Sub ClearListBox(ByVal T As ListBox)
T.Items.Clear()
End Sub
Private Sub ClearGroupbox(ByVal T As GroupBox)
T.Controls.ClearControls()
End Sub
<Runtime.CompilerServices.Extension()> _
Public Sub ClearControls(ByVal Controls As ControlCollection)
For Each Control In Controls
If ControlDefaults.ContainsKey(Control.GetType()) Then
ControlDefaults(Control.GetType()).Invoke(Control)
End If
Next
End Sub
Private _ControlDefaults As Dictionary(Of Type, Action(Of Control))
Private ReadOnly Property ControlDefaults() As Dictionary(Of Type, Action(Of Control))
Get
If (_ControlDefaults Is Nothing) Then
_ControlDefaults = New Dictionary(Of Type, Action(Of Control))
_ControlDefaults.Add(GetType(TextBox), AddressOf ClearTextBox)
_ControlDefaults.Add(GetType(CheckBox), AddressOf ClearCheckBox)
_ControlDefaults.Add(GetType(ListBox), AddressOf ClearListBox)
_ControlDefaults.Add(GetType(GroupBox), AddressOf ClearGroupbox)
End If
Return _ControlDefaults
End Get
End Property
End Module
Calling: 呼叫:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.Controls.ClearControls()
End Sub
I'm just posting this here so that people can see how to do the same thing in VB. 我只是在这里发布这个,以便人们可以看到如何在VB中做同样的事情。
private void FormReset() { ViewState.Clear(); private void FormReset(){ViewState.Clear(); Response.Redirect(Request.Url.AbsoluteUri.ToString()); 的Response.Redirect(Request.Url.AbsoluteUri.ToString()); } }
Below are methods I use to clear text from a type of control that implements ITextBox. 下面是我用从一个类型的控制实现ITextBox明文的方法。
I noticed in the example default boolean values are set. 我注意到在示例中设置了默认的布尔值。 I'm sure you can modify it to set default values of boolean components. 我相信你可以修改它来设置布尔组件的默认值。
Pass the Clear method a control type (TextBox, Label... etc) and a control collection, and it will clear all text from controls that implement ITextBox. 将Clear方法传递给控件类型(TextBox,Label ...等)和控件集合,它将清除实现ITextBox的控件中的所有文本。
Something like this: 像这样的东西:
//Clears the textboxes
WebControlUtilities.ClearControls<TextBox>(myPanel.Controls);
The Clear method is meant for a Page or Masterpage. Clear方法适用于页面或母版页。 The control collection type may vary. 控件集合类型可能有所不同。 ie. 即。 Form, ContentPlaceHolder.. etc Form,ContentPlaceHolder等
/// <summary>
/// Clears Text from Controls...ie TextBox, Label, anything that implements ITextBox
/// </summary>
/// <typeparam name="T">Collection Type, ie. ContentPlaceHolder..</typeparam>
/// <typeparam name="C">ie TextBox, Label, anything that implements ITextBox</typeparam>
/// <param name="controls"></param>
public static void Clear<T, C>(ControlCollection controls)
where C : ITextControl
where T : Control
{
IEnumerable<T> placeHolders = controls.OfType<T>();
List<T> holders = placeHolders.ToList();
foreach (T holder in holders)
{
IEnumerable<C> enumBoxes = holder.Controls.OfType<C>();
List<C> boxes = enumBoxes.ToList();
foreach (C box in boxes)
{
box.Text = string.Empty;
}
}
}
/// <summary>
/// Clears the text from control.
/// </summary>
/// <typeparam name="C"></typeparam>
/// <param name="controls">The controls.</param>
public static void ClearControls<C>(ControlCollection controls) where C : ITextControl
{
IEnumerable<C> enumBoxes = controls.OfType<C>();
List<C> boxes = enumBoxes.ToList();
foreach (C box in boxes)
{
box.Text = string.Empty;
}
}
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