在图形变换比例后缺少第一个像素列的一半

我注意到在OnPaint事件上的图形变换比例之后，不会绘制图像的第一个像素列的一半。

重现它所需的所有代码都在post的末尾。 基本上我已经创建了一个派生自PictureBox的类，名为PictureBox2，它会覆盖OnPaint方法来执行Scale转换。 它还将InterpolationMode更改为NearestNeighbor以防止Graphics更改像素外观。

PictureBox控件已添加到名为Form6_GraphicsTest的Form中。 控制在所有方面都是固定的。 PictureBox2背面颜色更改为蓝色，Form返回颜色为深灰色。

正如您在下面的图像中看到的那样，只绘制了图像第一个像素列的1/2。 为什么？？ 我在这里遗漏了什么？

这是原始的10×10 8bpp图像：

编辑 – 解决方案对于一些奇怪的原因，PixelOffsetMode.Default吃了0.5像素。 解决方案：PixelOffsetMode.Half或HighQuality！

代码PictureBox2.cs

using System.Drawing; using System.Drawing.Drawing2D; using System.Windows.Forms; namespace GraphicsTest { public class PictureBox2 : PictureBox { public PointF Zoom = new PointF(20, 20); private InterpolationMode interpolationMode = InterpolationMode.NearestNeighbor; /// 
 /// Paint the image /// 
 /// The paint event protected override void OnPaint(PaintEventArgs e) { if (IsDisposed) return; if (Image != null) { if (e.Graphics.InterpolationMode != interpolationMode) e.Graphics.InterpolationMode = interpolationMode; using (Matrix transform = e.Graphics.Transform) { //e.Graphics.ResetTransform(); if (Zoom.X != 1.0 || Zoom.Y != 1.0) transform.Scale(Zoom.X, Zoom.Y, MatrixOrder.Append); //if (ImageDisplayLocation.X != 0 || ImageDisplayLocation.Y != 0) //Convert translation back to display pixel unit. // transform.Translate(ImageDisplayLocation.X / Zoom.X, ImageDisplayLocation.Y / Zoom.Y); e.Graphics.Transform = transform; } } base.OnPaint(e); //If you want to draw something over the control in control coordinate, you must first reset the transformation! :D //e.Graphics.ResetTransform(); //Draw your stuff } } } 

代码Form6_GraphicsTest.cs：

 using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace GraphicsTest { public class Form6_GraphicsTest : Form { public Form6_GraphicsTest() { InitializeComponent(); Bitmap bmp = new Bitmap(@"D:\Test 10x10.8bpp.png"); this.pictureBox21.Image = bmp; this.pictureBox21.Zoom = new PointF(20,20); this.ClientSize = new Size(Convert.ToInt32(this.pictureBox21.Zoom.X * bmp.Width) + 30, Convert.ToInt32(this.pictureBox21.Zoom.Y * bmp.Height) + 30); } /// 
 /// Required designer variable. /// 
 private System.ComponentModel.IContainer components = null; /// 
 /// Clean up any resources being used. /// 
 /// true if managed resources should be disposed; otherwise, false. protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// 
 /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// 
 private void InitializeComponent() { this.pictureBox21 = new GraphicsTest.PictureBox2(); ((System.ComponentModel.ISupportInitialize)(this.pictureBox21)).BeginInit(); this.SuspendLayout(); // // pictureBox21 // this.pictureBox21.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right))); this.pictureBox21.BackColor = System.Drawing.SystemColors.Highlight; this.pictureBox21.Location = new System.Drawing.Point(12, 12); this.pictureBox21.Name = "pictureBox21"; this.pictureBox21.Size = new System.Drawing.Size(260, 238); this.pictureBox21.TabIndex = 0; this.pictureBox21.TabStop = false; // // Form6_GraphicsTest // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.BackColor = System.Drawing.SystemColors.ControlDarkDark; this.ClientSize = new System.Drawing.Size(284, 262); this.Controls.Add(this.pictureBox21); this.Name = "Form6_GraphicsTest"; this.Text = "Form6_GraphicsTest"; ((System.ComponentModel.ISupportInitialize)(this.pictureBox21)).EndInit(); this.ResumeLayout(false); } #endregion private PictureBox2 pictureBox21; } } 

Answer 1

它可能与PixelOffsetMode有关吗？ 这可能与其他post有关 。 它与渲染效率有关…