CheckedChanged not triggering

I am trying to create a winform application. Accidentally I found that Radiobutton.Checked event is fired when we programmatically assign true to RadioButton.Checked. But it is not fired when we programmatically assign false to Radiobutton.Checked. But it fires, when we manually checked/unchecked it. Here is a sample Code. Copy it,compile it and run it to check

using System.Windows.Forms;
using System;
using System.ComponentModel;
using System.Windows;

namespace Temp
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        //radioButton1.Checked = true;
        //radioButton2.Checked = true;
        radioButton1.Checked = false;
        radioButton2.Checked = false;
    }

    private void radioButton1_CheckedChanged(object sender, EventArgs e)
    {
        System.Windows.Forms.RadioButton tempRB = (System.Windows.Forms.RadioButton)sender;
        MessageBox.Show(tempRB.Name + " : " + (tempRB.Checked ? "Checked" : "Unchecked"));
        //radioButton2.Checked = !radioButton1.Checked;
    }
}
partial class Form1
{
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private System.ComponentModel.IContainer components = null;

    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    #region Windows Form Designer generated code

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
        this.button1 = new System.Windows.Forms.Button();
        this.groupBox1 = new System.Windows.Forms.GroupBox();
        this.radioButton1 = new System.Windows.Forms.RadioButton();
        this.radioButton2 = new System.Windows.Forms.RadioButton();
        this.groupBox1.SuspendLayout();
        this.SuspendLayout();
        // 
        // button1
        // 
        this.button1.Location = new System.Drawing.Point(173, 84);
        this.button1.Name = "button1";
        this.button1.Size = new System.Drawing.Size(75, 23);
        this.button1.TabIndex = 1;
        this.button1.Text = "button1";
        this.button1.UseVisualStyleBackColor = true;
        this.button1.Click += new System.EventHandler(this.button1_Click);
        // 
        // groupBox1
        // 
        this.groupBox1.Controls.Add(this.radioButton2);
        this.groupBox1.Controls.Add(this.radioButton1);
        this.groupBox1.Location = new System.Drawing.Point(385, 56);
        this.groupBox1.Name = "groupBox1";
        this.groupBox1.Size = new System.Drawing.Size(200, 100);
        this.groupBox1.TabIndex = 2;
        this.groupBox1.TabStop = false;
        this.groupBox1.Text = "groupBox1";
        // 
        // radioButton1
        // 
        this.radioButton1.AutoSize = true;
        this.radioButton1.Location = new System.Drawing.Point(21, 28);
        this.radioButton1.Name = "radioButton1";
        this.radioButton1.Size = new System.Drawing.Size(85, 17);
        this.radioButton1.TabIndex = 0;
        this.radioButton1.Text = "radioButton1";
        this.radioButton1.UseVisualStyleBackColor = true;
        this.radioButton1.CheckedChanged += new System.EventHandler(this.radioButton1_CheckedChanged);
        // 
        // radioButton2
        // 
        this.radioButton2.AutoSize = true;
        this.radioButton2.Location = new System.Drawing.Point(21, 52);
        this.radioButton2.Name = "radioButton2";
        this.radioButton2.Size = new System.Drawing.Size(85, 17);
        this.radioButton2.TabIndex = 1;
        this.radioButton2.Text = "radioButton2";
        this.radioButton2.UseVisualStyleBackColor = true;
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(663, 261);
        this.Controls.Add(this.groupBox1);
        this.Controls.Add(this.button1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.groupBox1.ResumeLayout(false);
        this.groupBox1.PerformLayout();
        this.ResumeLayout(false);
        this.PerformLayout();
    }

    #endregion

    private System.Windows.Forms.Button button1;
    private System.Windows.Forms.GroupBox groupBox1;
    private System.Windows.Forms.RadioButton radioButton2;
    private System.Windows.Forms.RadioButton radioButton1;
}
static class Temp
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}
}

Can anybody give an explanation about this. And also help me on how to fire RadioButton.Checked event when it got assigned false programmatically.
Note: I am using .net 3.5,Windows 10.

EDIT:
I am adding slightly modified code. In this "Uncheck" button didn’t trigger anything. But "Check Both" triggers two times CheckedChanged event. Check this code

using System.Windows.Forms;
using System;
using System.ComponentModel;
using System.Windows;

namespace Temp
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        radioButton1.Checked = false;
        radioButton2.Checked = false;
    }

    private void button2_Click(object sender, EventArgs e)
    {
        radioButton1.Checked = true;
        radioButton2.Checked = true;
    }

    private void radioButton1_CheckedChanged(object sender, EventArgs e)
    {
        System.Windows.Forms.RadioButton tempRB = (System.Windows.Forms.RadioButton)sender;
        MessageBox.Show(tempRB.Name + " : " + (tempRB.Checked ? "Checked" : "Unchecked"));
        //radioButton2.Checked = !radioButton1.Checked;
    }
}
partial class Form1
{
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private System.ComponentModel.IContainer components = null;

    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    #region Windows Form Designer generated code

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
        this.button1 = new System.Windows.Forms.Button();
        this.groupBox1 = new System.Windows.Forms.GroupBox();
        this.radioButton1 = new System.Windows.Forms.RadioButton();
        this.radioButton2 = new System.Windows.Forms.RadioButton();
        this.button2 = new System.Windows.Forms.Button();
        this.groupBox1.SuspendLayout();
        this.SuspendLayout();
        // 
        // button1
        // 
        this.button1.Location = new System.Drawing.Point(173, 84);
        this.button1.Name = "button1";
        this.button1.Size = new System.Drawing.Size(75, 23);
        this.button1.TabIndex = 1;
        this.button1.Text = "UnCheck";
        this.button1.UseVisualStyleBackColor = true;
        this.button1.Click += new System.EventHandler(this.button1_Click);
        // 
        // button2
        // 
        this.button2.Location = new System.Drawing.Point(173, 132);
        this.button2.Name = "button2";
        this.button2.Size = new System.Drawing.Size(75, 23);
        this.button2.TabIndex = 3;
        this.button2.Text = "Check Both";
        this.button2.UseVisualStyleBackColor = true;
        this.button2.Click += new System.EventHandler(this.button2_Click);
        // 
        // groupBox1
        // 
        this.groupBox1.Controls.Add(this.radioButton2);
        this.groupBox1.Controls.Add(this.radioButton1);
        this.groupBox1.Location = new System.Drawing.Point(385, 56);
        this.groupBox1.Name = "groupBox1";
        this.groupBox1.Size = new System.Drawing.Size(200, 100);
        this.groupBox1.TabIndex = 2;
        this.groupBox1.TabStop = false;
        this.groupBox1.Text = "groupBox1";
        // 
        // radioButton1
        // 
        this.radioButton1.AutoSize = true;
        this.radioButton1.Location = new System.Drawing.Point(21, 28);
        this.radioButton1.Name = "radioButton1";
        this.radioButton1.Size = new System.Drawing.Size(85, 17);
        this.radioButton1.TabIndex = 0;
        this.radioButton1.Text = "radioButton1";
        this.radioButton1.UseVisualStyleBackColor = true;
        this.radioButton1.CheckedChanged += new System.EventHandler(this.radioButton1_CheckedChanged);
        // 
        // radioButton2
        // 
        this.radioButton2.AutoSize = true;
        this.radioButton2.Location = new System.Drawing.Point(21, 52);
        this.radioButton2.Name = "radioButton2";
        this.radioButton2.Size = new System.Drawing.Size(85, 17);
        this.radioButton2.TabIndex = 1;
        this.radioButton2.Text = "radioButton2";
        this.radioButton2.UseVisualStyleBackColor = true;
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(663, 261);
        this.Controls.Add(this.groupBox1);
        this.Controls.Add(this.button1);
        this.Controls.Add(this.button2);
        this.Name = "Form1";
        this.Text = "Form1";
        this.groupBox1.ResumeLayout(false);
        this.groupBox1.PerformLayout();
        this.ResumeLayout(false);
        this.PerformLayout();
    }

    #endregion

    private System.Windows.Forms.Button button2;
    private System.Windows.Forms.Button button1;
    private System.Windows.Forms.GroupBox groupBox1;
    private System.Windows.Forms.RadioButton radioButton2;
    private System.Windows.Forms.RadioButton radioButton1;
}
static class Temp
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}
}