Added fixes provided on the issue section

RJTextBox.cs

@@ -21,6 +21,7 @@ public partial class RJTextBox : UserControl
         private int borderSize = 2;
         private bool underlinedStyle = false;
         private bool isFocused = false;
+	private bool removeNewline = false;
 
         private int borderRadius = 0;
         private Color placeholderColor = Color.DarkGray;
@@ -31,13 +32,25 @@ public partial class RJTextBox : UserControl
         //Events
         public event EventHandler _TextChanged;
 
+         // Cached render point
+        private Rectangle rectBorderSmooth;
+        private Rectangle rectBorder;
+        private int smoothSize;
+
+        private GraphicsPath pathBorderSmooth;
+        private GraphicsPath pathBorder;
+        private GraphicsPath pathTxt;
+
         #endregion
 
         //-> Constructor
         public RJTextBox()
         {
             //Created by designer
             InitializeComponent();
+	    SetStyle(ControlStyles.AllPaintingInWmPaint, true);
+            SetStyle(ControlStyles.UserPaint, true);
+            SetStyle(ControlStyles.DoubleBuffer, true);
         }
 
         #region -> Properties
@@ -68,6 +81,7 @@ public int BorderSize
                 if (value >= 1)
                 {
                     borderSize = value;
+		    layoutChanged = true;
                     this.Invalidate();
                 }
             }
@@ -84,6 +98,16 @@ public bool UnderlinedStyle
             }
         }
 
+        [Category("RJ Code Advance")]
+        public bool RemoveNewline
+        {
+            get { return removeNewline; }
+            set
+            {
+                removeNewline = value;
+            }
+        }
+
         [Category("RJ Code Advance")]
         public bool PasswordChar
         {
@@ -109,8 +133,12 @@ public override Color BackColor
             get { return base.BackColor; }
             set
             {
-                base.BackColor = value;
-                textBox1.BackColor = value;
+		try
+		{
+			base.BackColor = value;
+			textBox1.BackColor = value;
+		}
+		catch (ArgumentException) { return; }
             }
         }
 
@@ -148,8 +176,13 @@ public string Texts
             }
             set
             {
-                textBox1.Text = value;
-                SetPlaceholder();
+                if (!string.IsNullOrWhiteSpace(value))
+                {
+		    RemovePlaceholder();
+		    string val = value;
+        	    if (removeNewline) { val = val.Replace("\n", "").Replace("\r", ""); ; }
+                    textBox1.Text = val;
+                }
             }
         }
 
@@ -162,6 +195,7 @@ public int BorderRadius
                 if (value >= 0)
                 {
                     borderRadius = value;
+		    layoutChanged = true;
                     this.Invalidate();//Redraw control
                 }
             }
@@ -191,14 +225,14 @@ public string PlaceholderText
             }
         }
 
-
-
         #endregion
 
         #region -> Overridden methods
         protected override void OnResize(EventArgs e)
         {
             base.OnResize(e);
+	    layoutChanged = true;
+            Invalidate();
             if (this.DesignMode)
                 UpdateControlHeight();
         }
@@ -215,18 +249,17 @@ protected override void OnPaint(PaintEventArgs e)
             if (borderRadius > 1)//Rounded TextBox
             {
                 //-Fields
-                var rectBorderSmooth = this.ClientRectangle;
-                var rectBorder = Rectangle.Inflate(rectBorderSmooth, -borderSize, -borderSize);
-                int smoothSize = borderSize > 0 ? borderSize : 1;
-
-                using (GraphicsPath pathBorderSmooth = GetFigurePath(rectBorderSmooth, borderRadius))
-                using (GraphicsPath pathBorder = GetFigurePath(rectBorder, borderRadius - borderSize))
+		if (layoutChanged) 
+  		{
+    			RefreshDataPoints();
+       			this.Region = new Region(pathBorderSmooth); // Set the rounded region of UserControl
+       		}
                 using (Pen penBorderSmooth = new Pen(this.Parent.BackColor, smoothSize))
                 using (Pen penBorder = new Pen(borderColor, borderSize))
                 {
                     //-Drawing
-                    this.Region = new Region(pathBorderSmooth);//Set the rounded region of UserControl
                     if (borderRadius > 15) SetTextBoxRoundedRegion();//Set the rounded region of TextBox component
+		    if (layoutChanged) { layoutChanged = false; }
                     graph.SmoothingMode = SmoothingMode.AntiAlias;
                     penBorder.Alignment = System.Drawing.Drawing2D.PenAlignment.Center;
                     if (isFocused) penBorder.Color = borderFocusColor;
@@ -253,7 +286,11 @@ protected override void OnPaint(PaintEventArgs e)
                 //Draw border
                 using (Pen penBorder = new Pen(borderColor, borderSize))
                 {
-                    this.Region = new Region(this.ClientRectangle);
+                    if (layoutChanged)
+                    {
+                        this.Region = new Region(this.ClientRectangle);
+                        layoutChanged = false;
+                    }
                     penBorder.Alignment = System.Drawing.Drawing2D.PenAlignment.Inset;
                     if (isFocused) penBorder.Color = borderFocusColor;
 
@@ -289,6 +326,18 @@ private void RemovePlaceholder()
                     textBox1.UseSystemPasswordChar = true;
             }
         }        
+
+ 	private void RefreshDataPoints()
+        {
+            rectBorderSmooth = this.ClientRectangle;
+            rectBorder = Rectangle.Inflate(rectBorderSmooth, -borderSize, -borderSize);
+            smoothSize = borderSize > 0 ? borderSize : 1;
+            pathBorderSmooth?.Dispose();
+            pathBorderSmooth = GetFigurePath(rectBorderSmooth, borderRadius);
+            pathBorder?.Dispose();
+            pathBorder = GetFigurePath(rectBorder, borderRadius - borderSize);
+        }
+
         private GraphicsPath GetFigurePath(Rectangle rect, int radius)
         {
             GraphicsPath path = new GraphicsPath();
@@ -304,19 +353,17 @@ private GraphicsPath GetFigurePath(Rectangle rect, int radius)
         }
         private void SetTextBoxRoundedRegion()
         {
-            GraphicsPath pathTxt;
-            if (Multiline)
-            {
-                pathTxt = GetFigurePath(textBox1.ClientRectangle, borderRadius - borderSize);
-                textBox1.Region = new Region(pathTxt);
-            }
-            else
+            if (layoutChanged)
             {
-                pathTxt = GetFigurePath(textBox1.ClientRectangle, borderSize * 2);
+                pathTxt?.Dispose();
+                int effectiveBorderRadius = Multiline
+                    ? borderRadius - borderSize
+                    : borderSize * 2;
+                pathTxt = GetFigurePath(textBox1.ClientRectangle, effectiveBorderRadius);
                 textBox1.Region = new Region(pathTxt);
             }
-            pathTxt.Dispose();
         }
+
         private void UpdateControlHeight()
         {
             if (textBox1.Multiline == false)
@@ -334,6 +381,7 @@ private void UpdateControlHeight()
         #region -> TextBox events
         private void textBox1_TextChanged(object sender, EventArgs e)
         {
+			if (isPlaceholder) return;
             if (_TextChanged != null)
                 _TextChanged.Invoke(sender, e);
         }
@@ -360,6 +408,7 @@ private void textBox1_Enter(object sender, EventArgs e)
             this.Invalidate();
             RemovePlaceholder();
         }
+
         private void textBox1_Leave(object sender, EventArgs e)
         {
             isFocused = false;