如何在C＃中创建添加控件的功能 [英] How can I make a function to Add Control in C#

问题描述

如何使一个函数有一个参数接收控件的类型如（Button，GroupBox，Panel，TextBox，Label ...等）



private void CreateControl（）

{

Button myButton = new Button（）;

this.Controls.Add（myButton）;

}



我需要设置一个参数来控制控件的类型并不总是一个按钮。



请帮助

How can I make a function has 1 parameter recieves the type of the Control like(Button, GroupBox,Panel,TextBox,Label ...etc)

private void CreateControl()
{
Button myButton=new Button();
this.Controls.Add(myButton);
}

I need to put a paramter to spicify the type of the control not always a button.

Please help

推荐答案

嗯，你可以这样做：

Well, you could do this:

private void CreateControl(Type controlType)
{
    Control control = Activator.CreateInstance(controlType) as Control;
    if (control != null) Controls.Add(control);
}

这有点复杂，因为它在很大程度上取决于您要传递的参数类型：您需要一个参数告诉你要创建什么类型的控件，这意味着传递一个字符串作为类名，或者一个Type指示控件应该是什么类型 - 这将使你的外部代码调用它复杂 - 但是我有多复杂无法分辨。

一般来说，这种方法并不是一个好主意 - 这是可能的，但这并不意味着你应该这样做 - 这通常意味着你的设计过于复杂或经过深思熟虑。但也有例外。



一种方法是通过泛型：

That's a little complex, because it depends to a large extent of what kind of parameter you want to pass: You need a parameter which tells you what type of control to create, which means passing it a string which is the class name, or a Type which indicates what type the control should be - and that's going to make your external code to call it complex - but how complex I can't tell.
Generally, this kind of aproach is not a good idea - it's possible, but that doesn't mean you should do it - it normally means your design is overcomplicated or badly thought out. There are exceptions though.

One way to do it is via generics:

private void CreateControl<T>() where T : Control, new()
    {
    T t = new T();
    Controls.Add(t);
    }

然后你创建这样的实例：

You then create the instance like this:

CreateControl<Button>();

否则，它的参数类型和反射使用 Activator.CreateInstance [ ^ ]

您好，



以下是示例代码。只需采取组合框/下拉和放大器列出要动态创建的控件&分配一些值。

点击按钮执行代码。

例如文本框为值1，标记为值2

和调用函数CreateControl（）&申请swith case。



这是小代码;

取一个整数作为全局变量

Hello ,

Here is the sample code. Just take the combobox/Dropdown & list the control which you want to Create Dynamically & assign some value.
Take the Button to execute the code on Click.
For Example textbox as value 1,label as value 2
and Call Function CreateControl() & apply swith case.

Here is the small Code;
Take one integer as global variable

int cleft = 1; 

变量用于定位目的。



然后修改你的函数CreateControl（）

the variable is for the positioning purpose.

Then Modify your function CreateControl()

<pre lang="c#">private void CreateControl()
{
switch (urDropdown.selectedvaue)
                    {
                        case 1://TextBox
                            Button myButton = new Button();
                            this.Controls.Add(myButton);
                            myButton.Top = cleft * 25;
                            myButton.Left = 100;
                            myButton.Text = "TextBox " + this.cleft.ToString();
                            cleft++;
                            break;

                        case 2://LAbel
                            Label label1 = new Label();
                            this.Controls.Add(label1);
                            label1.Top = cleft * 25;
                            label1.Left = 100;
                            label1.Text = "label1 " + this.cleft.ToString();
                            cleft++;
                            break;
case 3://Button 
break;
                        default:
                    }

}





该代码适用于LAbel& Textbox.your将它扩展为您想要的任意数量的控件。您可以将它用于textbox，combobox，Groupbox，panel&等等。

请小心试试，抓住你的代码来发现任何错误。

让我知道这是否对你有所帮助。？

快乐编码： - ）

}


The code is for LAbel & Textbox.your expand it to any number of controls you want.You can take it for textbox,combobox,Groupbox,panel & so on .
Kindly take try, catch in your code to catch any error when it occurs.
Let me know whether this helped you or not.?
Happy Coding :-)

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