C#正方形图片的绘制方法

本文为大家分享了C#绘制正方形图片的的具体代码，供大家参考。

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace treads
{
/// <summary>
/// 制作小正方形
/// </summary>
class Class3
{
  private string srcFileName = @"x";//获取图片的路径
  private string srcFileName1 = @"x";//要保持图片的新路径

 

  /// <summary>
  /// 保存图片
  /// </summary>
  /// <param name="image">Image 对象</param>
  /// <param name="savePath">保存路径</param>
  /// <param name="ici">指定格式的编解码参数</param>
  private static void SaveImage(Image image, string savePath, ImageCodecInfo ici)
  {
    //设置 原图片 对象的 EncoderParameters 对象
    EncoderParameters parameters = new EncoderParameters(1);
    parameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, ((long)100));
    image.Save(savePath, ici, parameters);
    parameters.Dispose();
  }

  /// <summary>
  /// 获取图像编码解码器的所有相关信息
  /// </summary>
  /// <param name="mimeType">包含编码解码器的多用途网际邮件扩充协议 (MIME) 类型的字符串</param>
  /// <returns>返回图像编码解码器的所有相关信息</returns>
  private static ImageCodecInfo GetCodecInfo(string mimeType)
  {
    ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
    foreach (ImageCodecInfo ici in CodecInfo)
    {
      if (ici.MimeType == mimeType)
        return ici;
    }
    return null;
  }

  /// <summary>
  /// 计算新尺寸
  /// </summary>
  /// <param name="width">原始宽度</param>
  /// <param name="height">原始高度</param>
  /// <param name="maxWidth">最大新宽度</param>
  /// <param name="maxHeight">最大新高度</param>
  /// <returns></returns>
  private static Size ResizeImage(int width, int height, int maxWidth, int maxHeight)
  {
    //此次2012-02-05修改过=================
    if (maxWidth <= 0)
      maxWidth = width;
    if (maxHeight <= 0)
      maxHeight = height;
    //以上2012-02-05修改过=================
    decimal MAX_WIDTH = (decimal)maxWidth;
    decimal MAX_HEIGHT = (decimal)maxHeight;
    decimal ASPECT_RATIO = MAX_WIDTH / MAX_HEIGHT;

    int newWidth, newHeight;
    decimal originalWidth = (decimal)width;
    decimal originalHeight = (decimal)height;

    if (originalWidth > MAX_WIDTH || originalHeight > MAX_HEIGHT)
    {
      decimal factor;
      // determine the largest factor 
      if (originalWidth / originalHeight > ASPECT_RATIO)
      {
        factor = originalWidth / MAX_WIDTH;
        newWidth = Convert.ToInt32(originalWidth / factor);
        newHeight = Convert.ToInt32(originalHeight / factor);
      }
      else
      {
        factor = originalHeight / MAX_HEIGHT;
        newWidth = Convert.ToInt32(originalWidth / factor);
        newHeight = Convert.ToInt32(originalHeight / factor);
      }
    }
    else
    {
      newWidth = width;
      newHeight = height;
    }
    return new Size(newWidth, newHeight);
  }

  /// <summary>
  /// 得到图片格式
  /// </summary>
  /// <param name="name">文件名称</param>
  /// <returns></returns>
  public static ImageFormat GetFormat(string name)
  {
    string ext = name.Substring(name.LastIndexOf(".") + 1);
    switch (ext.ToLower())
    {
      case "jpg":
      case "jpeg":
        return ImageFormat.Jpeg;
      case "bmp":
        return ImageFormat.Bmp;
      case "png":
        return ImageFormat.Png;
      case "gif":
        return ImageFormat.Gif;
      default:
        return ImageFormat.Jpeg;
    }
  }
 

  /// <summary>
  /// 制作小正方形
  /// </summary>
  /// <param name="image">图片对象</param>
  /// <param name="newFileName">新地址</param>
  /// <param name="newSize">长度或宽度</param>
  public static void MakeSquareImage(Image image, string newFileName, int newSize)
  {
    int i = 0;
    int width = image.Width;
    int height = image.Height;
    if (width > height)
      i = height;
    else
      i = width;

    Bitmap b = new Bitmap(newSize, newSize);

    try
    {
      Graphics g = Graphics.FromImage(b);
      //设置高质量插值法
      g.InterpolationMode = InterpolationMode.HighQualityBicubic;
      //设置高质量,低速度呈现平滑程度
      g.SmoothingMode = SmoothingMode.AntiAlias;
      g.PixelOffsetMode = PixelOffsetMode.HighQuality;
      //清除整个绘图面并以透明背景色填充
      g.Clear(Color.Transparent);
      if (width < height)
        g.DrawImage(image, new Rectangle(0, 0, newSize, newSize), new Rectangle(0, (height - width) / 2, width, width), GraphicsUnit.Pixel);
      else
        g.DrawImage(image, new Rectangle(0, 0, newSize, newSize), new Rectangle((width - height) / 2, 0, height, height), GraphicsUnit.Pixel);

      SaveImage(b, newFileName, GetCodecInfo("image/" + GetFormat(newFileName).ToString().ToLower()));
    }
    finally
    {
      image.Dispose();
      b.Dispose();
    }
  }

  /// <summary>
  /// 制作小正方形
  /// </summary>
  /// <param name="fileName">图片文件名</param>
  /// <param name="newFileName">新地址</param>
  /// <param name="newSize">长度或宽度</param>
  public static void MakeSquareImage(string fileName,string newFileName, int newSize)
  {
    MakeSquareImage(Image.FromFile(fileName), newFileName, newSize);
  }
}
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程宝库。

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