我注意到在OnPaint事件上的图形转换比例之后,不会绘制图像的第一个像素列的一半.
@H_403_22@解决方法
重现它所需的所有代码都在帖子的末尾.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!
- 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;
- /// <summary>
- /// Paint the image
- /// </summary>
- /// <param name="e">The paint event</param>
- 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);
- }
- /// <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.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;
- }
- }
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…