How to access properties of a usercontrol in C#

问题

I've made a C# usercontrol with one textbox and one richtextbox.

How can I access the properties of the richtextbox from outside the usercontrol.

For example.. if i put it in a form, how can i use the Text propertie of the richtextbox???

thanks

回答1:

Cleanest way is to expose the desired properties as properties of your usercontrol, e.g:

class MyUserControl
{
  // expose the Text of the richtext control (read-only)
  public string TextOfRichTextBox
  {
    get { return richTextBox.Text; }
  }
  // expose the Checked Property of a checkbox (read/write)
  public bool CheckBoxProperty
  {
    get { return checkBox.Checked; }
    set { checkBox.Checked = value; }
  }


  //...
}

In this way you can control which properties you want to expose and whether they should be read/write or read-only. (of course you should use better names for the properties, depending on their meaning).

Another advantage of this approach is that it hides the internal implementation of your user control. Should you ever want to exchange your richtext control with a different one, you won't break the callers/users of your control.

回答2:

Change the access modifier ("Modifiers") of the RichTextBox in the property grid to Public.

回答3:

Add a property to the usercontrol like this

public string TextBoxText
{
    get
    {
        return textBox1.Text;
    }
    set
    {
        textBox1.Text = value;
    }
}

回答4:

I recently had some issues doing this with a custom class:

A user control had a public property which was of a custom class type. The designer by default tries to assign some value to it, so in the designer code, the line userControlThing.CustomClassProperty = null was being automatically added.

The intent was to be able to provide the user control with a custom class at any point while running the program (to change values visible to the user). Because the set {} portion did not check for null values, various errors were cropping up.

The solution was to change the property to a private one, and use two public methods to set and get the value. The designer will try to auto-assign properties, but leaves methods alone.

回答5:

You need to make a public property for the richtextbox, or expose some other property that does the job of setting the richtextbox text like:

private RichTextBox rtb;

public string RichTextBoxText
{
    get
    {
        return rtb.Text;
    }
    set
    {
        rtb.Text = value;
    }
}

来源：https://stackoverflow.com/questions/411316/how-to-access-properties-of-a-usercontrol-in-c-sharp

标签

user-controls

properties

richtextbox