从不同的表单更新控件

Question

我有一个主窗体 (frm_Main) 和设置窗体 (frm_Settings)，我想从 frm_Settings 更新一个位于 frm_Main 中的控件。到目前为止，我已经尝试在 frm_Main 中添加一个方法，然后从 frm_Settings 访问它，希望它能够工作，但它没有。这是我当前方法的代码：

主窗体

public partial class frm_Main : Form
{
    public frm_Main()
    {

    }

    public void ChangeBackColor(Color color)
    {
        richTextBox.BackColor = color;
    }
}

设置表单

public partial class frm_Settings : Form
{
    public frm_Settings()
    {

    }

    private void pbcl_editorBackColor_Click(object sender, EventArgs e)
    {
        ColorDialog editorBackColor = new ColorDialog();
        if (editorBackColor.ShowDialog() == DialogResult.OK)
        {
            Variables.Editor_BackColor = "#" + editorBackColor.Color.ToArgb().ToString("X");
            Color colour = ColorTranslator.FromHtml(Variables.Editor_ForeColor);
            var Main = new frm_Main();
            Main.ChangeBackColor(colour);
        }
    }
}

单击 ColorSelectorDialog 上的“确定”按钮后，没有任何反应，也没有任何更新。我在这里做错了什么？

Answer 1

试试这个

Settings.cs

public partial class frm_Settings : Form
{
    private frm_Main _main;
    public frm_Settings(frm_Main main)
    {
          _main = main;
    }

    private void pbcl_editorBackColor_Click(object sender, EventArgs e)
    {
        ColorDialog editorBackColor = new ColorDialog();
        if (editorBackColor.ShowDialog() == DialogResult.OK)
        {
            Variables.Editor_BackColor = "#" + editorBackColor.Color.ToArgb().ToString("X");
            Color colour = ColorTranslator.FromHtml(Variables.Editor_ForeColor);                
            _main.ChangeBackColor(colour);
        }
    }
}

Main.cs

public partial class frm_Main : Form
{
    public frm_Main()
    {

    }
    private void LaunchSetting()
    {
       var settings = new frm_Settings(this);
       settings.ShowDialog();
    }
    public void ChangeBackColor(Color color)
    {
        richTextBox.BackColor = color;
    }
}

编辑：

我们也可以处理它来创建一个事件

Settings.cs

public partial class frm_Settings : Form
{
    public delegate void ColorChangedHandler(Color color);
    public event ColorChangedHandler OnColorChangedHandler;
    public frm_Settings()
    {

    }

    private void pbcl_editorBackColor_Click(object sender, EventArgs e)
    {
        ColorDialog editorBackColor = new ColorDialog();
        if (editorBackColor.ShowDialog() == DialogResult.OK)
        {
            Variables.Editor_BackColor = "#" + editorBackColor.Color.ToArgb().ToString("X");
            Color colour = ColorTranslator.FromHtml(Variables.Editor_ForeColor);
            if (OnColorChangedHandler != null)
            {
               OnColorChangedHandler(colour);
            }
        }
    } 
}

Main.cs

public partial class frm_Main : Form
{
    public frm_Main()
    {

    }
    private void LaunchSetting()
    {
       var settings = new frm_Settings(this);
       settings.OnColorChangedHandler += OnColorChanged;
       settings.ShowDialog();
    }
    private void OnColorChanged(Color color)
    {
       ChangeBackColor(color);
    }
    public void ChangeBackColor(Color color)
    {
        richTextBox.BackColor = color;
    }
}