厚积薄发，丰富的公用类库积累，助你高效进行系统开发（6）----全屏截图、图标获取、图片打印、页面预览截屏、图片复杂操作等
俗话说，一个好汉十个帮，众人拾柴火焰高等都说明一个道理，有更多的资源，更丰富的积累，都是助你走向成功，走向顶峰的推动力。作为一个有多年开发经验的技术人员或者是初级的编程菜鸟，有着一些成熟、使用熟练的公用类库，能很高程度提升自己的软件开发能力和思维能力。另外，丰富的类库也是.NET的各种知识点的汇聚，经常查看优化，也是对自己能力深层次的提升。本篇继续公用类库系列的介绍，不同于前面几篇的主题，本篇主要介绍图片相关方面的类库操作，如果你对前面的类库介绍文章有兴趣，可以参考下面的连接了解。
/// <summary>
/// 图片下载完毕的时间处理
/// </summary>
public event ImageEventHandler DownloadCompleted;
/// <summary>
/// 图片处理委托定义
/// </summary>
/// <param name="image"></param>
public delegate void ImageEventHandler(Image image);
/// <summary>
/// 浏览区域大小
/// </summary>
public Size BrowserSize { get; set; }
/// <summary>
/// 页面URL地址
/// </summary>
public string URL { get; set; }
/// <summary>
/// 下载的图片对象
/// </summary>
public Image Image { get; private set; }
#endregion
#region 构造函数
/// <summary>
/// 构造函数,默认为屏幕大小
/// </summary>
public WebPageCapture() : this(Screen.PrimaryScreen.Bounds.Size) { }
/// <summary>
/// 构造函数，指定浏览区域大小
/// </summary>
/// <param name="width">宽度</param>
/// <param name="height">高度</param>
public WebPageCapture(int width, int height) : this(new Size(width, height)) { }
/// <summary>
/// 构造函数，指定浏览区域大小
/// </summary>
/// <param name="browserSize">浏览区域大小</param>
public WebPageCapture(Size browserSize)
#endregion
/// <summary>
/// 下载页面到图片中
/// </summary>
public void DownloadPage()
/// <summary>
/// 下载页面到图片中
/// </summary>
/// <param name="url">页面Url地址</param>
public void DownloadPage(string url)
到目前为止，类库的优化及内容介绍、例子实现同步进行，下面是最近的类库帮助文档整理截图。
1、全屏截图辅助控件 ScreenCaptureWindow
实现效果
1）本辅助类主要是用来方便实现对屏幕进行局部截图的功能，类似QQ截图的效果。
2）截图的时候，底图是当前屏幕的图像，加了灰度背景，当鼠标单击并拉动的时候，出现局部加亮区域，这个就是要截取的图片内容。图片截图后，用户可以实现自定义的保存等操作。
实现代码
1）辅助类提供的方法接口如下所示：
/// <summary>
/// 获取或设置截图的图片对象
/// </summary>
public Bitmap BitmapCache
/// <summary>
/// 图片截图结束后的事件处理
/// </summary>
public event EventHandler BitmapCropped;
/// <summary>
/// 拖动截图开始
/// </summary>
public Point DragStart
/// <summary>
/// 拖动截图结束
/// </summary>
public Point DragStop
/// </summary>
public Bitmap BitmapCache
/// <summary>
/// 图片截图结束后的事件处理
/// </summary>
public event EventHandler BitmapCropped;
/// <summary>
/// 拖动截图开始
/// </summary>
public Point DragStart
/// <summary>
/// 拖动截图结束
/// </summary>
public Point DragStop
2）辅助类ScreenCaptureWindow的使用例子代码如下所示（增加图片保存到文件的自定义操作）
public partial class Form1 : Form
{
private ScreenCaptureWindow captureWindow = null;
public Form1()
{
InitializeComponent();
}
private void captureWindow_BitmapCropped(object sender, EventArgs e)
{
if (captureWindow.DragStop != captureWindow.DragStart)
{
bool AutoSaveImages = false;
if (AutoSaveImages)
{
string path = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures);
string fileName = "Snap_" + DateTime.Now.Ticks.ToString() + Guid.NewGuid().ToString().Substring(0, 2) + ".jpg";
captureWindow.BitmapCache.Save(Path.Combine(path, fileName), ImageFormat.Jpeg);
}
}
}
private void btnScreenCapture_Click(object sender, EventArgs e)
{
if (captureWindow != null)
{
captureWindow.BitmapCropped -= new EventHandler(captureWindow_BitmapCropped);
captureWindow.Dispose();
captureWindow = null;
}
if (captureWindow == null)
{
captureWindow = new ScreenCaptureWindow();
captureWindow.BitmapCropped += new EventHandler(captureWindow_BitmapCropped);
}
captureWindow = new ScreenCaptureWindow();
captureWindow.Show();
captureWindow.TopMost = true;
captureWindow.TopMost = false;
}
}
{
private ScreenCaptureWindow captureWindow = null;
public Form1()
{
InitializeComponent();
}
private void captureWindow_BitmapCropped(object sender, EventArgs e)
{
if (captureWindow.DragStop != captureWindow.DragStart)
{
bool AutoSaveImages = false;
if (AutoSaveImages)
{
string path = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures);
string fileName = "Snap_" + DateTime.Now.Ticks.ToString() + Guid.NewGuid().ToString().Substring(0, 2) + ".jpg";
captureWindow.BitmapCache.Save(Path.Combine(path, fileName), ImageFormat.Jpeg);
}
}
}
private void btnScreenCapture_Click(object sender, EventArgs e)
{
if (captureWindow != null)
{
captureWindow.BitmapCropped -= new EventHandler(captureWindow_BitmapCropped);
captureWindow.Dispose();
captureWindow = null;
}
if (captureWindow == null)
{
captureWindow = new ScreenCaptureWindow();
captureWindow.BitmapCropped += new EventHandler(captureWindow_BitmapCropped);
}
captureWindow = new ScreenCaptureWindow();
captureWindow.Show();
captureWindow.TopMost = true;
captureWindow.TopMost = false;
}
}
最简化的操作就是只是把截图的图片放到在剪切板里面（默认），实现操作如下所示：
private ScreenCaptureWindow captureWindow = null;
private void btnScreenCapture_Click(object sender, EventArgs e)
{
captureWindow = new ScreenCaptureWindow();
captureWindow.Show();
captureWindow.TopMost = true;
captureWindow.TopMost = false;
}
{
captureWindow = new ScreenCaptureWindow();
captureWindow.Show();
captureWindow.TopMost = true;
captureWindow.TopMost = false;
}
2、本辅助类主要是用来方便实现获取文件、文件夹、扩展名的图标信息
IconReaderHelper。
实现效果
1）本辅助类主要是用来方便实现窗体的各种动画效果，包括创建、关闭、隐藏、移动状态的动画，动画支持滚动、滑动、各种方向变换、透明状态等。
实现代码
1）辅助类提供的方法接口如下所示
/// <summary>
/// 指定图标尺寸大小选项
/// </summary>
public enum IconSize
/// <summary>
/// 指定文件夹是打开还是关闭状态选项
/// </summary>
public enum FolderType
/// <summary>
/// 返回给定文件的图标
/// </summary>
/// <param name="name">文件路径名</param>
/// <param name="size">大图标还是小图标</param>
/// <param name="linkOverlay">是否包含链接图标</param>
/// <returns>System.Drawing.Icon</returns>
public static Icon GetFileIcon(string name, IconSize size, bool linkOverlay)
/// <summary>
/// 用于访问系统文件夹图标。
/// </summary>
/// <param name="size">大图标还是小图标</param>
/// <param name="folderType">文件夹是打开还是关闭状态</param>
/// <returns>System.Drawing.Icon</returns>
public static Icon GetFolderIcon(IconSize size, FolderType folderType)
/// <summary>
/// 获取文件或者文件夹图标的显示名称
/// </summary>
/// <param name="name">文件或文件夹路径</param>
/// <param name="isDirectory">是否为文件夹</param>
/// <returns></returns>
public static string GetDisplayName(string name, bool isDirectory)
#region 后缀名图标操作
/// <summary>
/// 添加扩展名小图标对象到ImageList集合中，并返回位置；如果存在，则返回对应的位置。
/// </summary>
/// <param name="images"></param>
/// <param name="extension"></param>
/// <returns></returns>
public static int GetIcon(ImageList images, string extension)
/// <summary>
/// 添加扩展名图标对象到ImageList集合中，并返回位置；如果存在，则返回对应的位置。
/// </summary>
/// <param name="images">ImageList集合</param>
/// <param name="extension">扩展名</param>
/// <param name="largeIcon">是否大图标</param>
/// <returns></returns>
public static int GetIcon(ImageList images, string extension, bool largeIcon)
/// <summary>
/// 获取扩展名的图标
/// </summary>
/// <param name="extension">扩展名</param>
/// <param name="large">是否为大图标</param>
/// <returns></returns>
public static Icon ExtractIconForExtension(string extension, bool large)
/// <summary>
/// 获取指定文件的关联图标
/// </summary>
/// <param name="stubPath">指定的文件路径</param>
/// <param name="large">是否为大图标</param>
/// <returns></returns>
public static Icon GetAssociatedIcon(string stubPath, bool large)
#endregion
/// </summary>
public enum IconSize
/// <summary>
/// 指定文件夹是打开还是关闭状态选项
/// </summary>
public enum FolderType
/// <summary>
/// 返回给定文件的图标
/// </summary>
/// <param name="name">文件路径名</param>
/// <param name="size">大图标还是小图标</param>
/// <param name="linkOverlay">是否包含链接图标</param>
/// <returns>System.Drawing.Icon</returns>
public static Icon GetFileIcon(string name, IconSize size, bool linkOverlay)
/// <summary>
/// 用于访问系统文件夹图标。
/// </summary>
/// <param name="size">大图标还是小图标</param>
/// <param name="folderType">文件夹是打开还是关闭状态</param>
/// <returns>System.Drawing.Icon</returns>
public static Icon GetFolderIcon(IconSize size, FolderType folderType)
/// <summary>
/// 获取文件或者文件夹图标的显示名称
/// </summary>
/// <param name="name">文件或文件夹路径</param>
/// <param name="isDirectory">是否为文件夹</param>
/// <returns></returns>
public static string GetDisplayName(string name, bool isDirectory)
#region 后缀名图标操作
/// <summary>
/// 添加扩展名小图标对象到ImageList集合中，并返回位置；如果存在，则返回对应的位置。
/// </summary>
/// <param name="images"></param>
/// <param name="extension"></param>
/// <returns></returns>
public static int GetIcon(ImageList images, string extension)
/// <summary>
/// 添加扩展名图标对象到ImageList集合中，并返回位置；如果存在，则返回对应的位置。
/// </summary>
/// <param name="images">ImageList集合</param>
/// <param name="extension">扩展名</param>
/// <param name="largeIcon">是否大图标</param>
/// <returns></returns>
public static int GetIcon(ImageList images, string extension, bool largeIcon)
/// <summary>
/// 获取扩展名的图标
/// </summary>
/// <param name="extension">扩展名</param>
/// <param name="large">是否为大图标</param>
/// <returns></returns>
public static Icon ExtractIconForExtension(string extension, bool large)
/// <summary>
/// 获取指定文件的关联图标
/// </summary>
/// <param name="stubPath">指定的文件路径</param>
/// <param name="large">是否为大图标</param>
/// <returns></returns>
public static Icon GetAssociatedIcon(string stubPath, bool large)
#endregion
2）辅助类IconReaderHelper的使用例子代码如下所示
private void btnGetIcon_Click(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(this.txtFilPath.Text))
{
//获取文件的图标
Icon ico = IconReaderHelper.GetFileIcon(this.txtFilPath.Text,
IconReaderHelper.IconSize.Large, false);
this.pictureBox1.Image = Bitmap.FromHicon(ico.Handle);
//获取对应图标的说明名称
string name = IconReaderHelper.GetDisplayName(this.txtFilPath.Text, false);
this.Text = name;
}
//获取系统文件夹图标
Icon ico2 = IconReaderHelper.GetFolderIcon(IconReaderHelper.IconSize.Large,
IconReaderHelper.FolderType.Open);
this.pictureBox2.Image = Bitmap.FromHicon(ico2.Handle);
}
private void btnGetExtensionIcon_Click(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(this.txtExtension.Text))
{
//获取扩展名图标
Icon ico = IconReaderHelper.ExtractIconForExtension(this.txtExtension.Text, true);
this.pictureBox2.Image = Bitmap.FromHicon(ico.Handle);
}
{
if (!string.IsNullOrEmpty(this.txtFilPath.Text))
{
//获取文件的图标
Icon ico = IconReaderHelper.GetFileIcon(this.txtFilPath.Text,
IconReaderHelper.IconSize.Large, false);
this.pictureBox1.Image = Bitmap.FromHicon(ico.Handle);
//获取对应图标的说明名称
string name = IconReaderHelper.GetDisplayName(this.txtFilPath.Text, false);
this.Text = name;
}
//获取系统文件夹图标
Icon ico2 = IconReaderHelper.GetFolderIcon(IconReaderHelper.IconSize.Large,
IconReaderHelper.FolderType.Open);
this.pictureBox2.Image = Bitmap.FromHicon(ico2.Handle);
}
private void btnGetExtensionIcon_Click(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(this.txtExtension.Text))
{
//获取扩展名图标
Icon ico = IconReaderHelper.ExtractIconForExtension(this.txtExtension.Text, true);
this.pictureBox2.Image = Bitmap.FromHicon(ico.Handle);
}
}
2、实现图片打印操作，并提供图片打印预览功能，图片自动根据页面进行居中、缩放、对齐等操作辅助类
ImagePrintHelper
实现效果
1）本辅助类主要是用来方便实现图片打印操作，并提供图片打印预览功能，图片自动根据页面进行居中、缩放、对齐等默认操作。
打印预览的时候，自动调整图片为止，如下：
或者打印对话框
实现代码
1）辅助类提供的方法接口如下所示
#region 配置参数
/// <summary>
/// 将在页面上居中打印输出。
/// </summary>
public bool AllowPrintCenter = true;
/// <summary>
/// 旋转图像，如果它符合页面更好
/// </summary>
public bool AllowPrintRotate = true;
/// <summary>
/// 缩放图像，以更好地适应页面
/// </summary>
public bool AllowPrintEnlarge = true;
/// <summary>
/// 允许打印收缩，以更好适应页面
/// </summary>
public bool AllowPrintShrink = true;
#endregion
/// <summary>
/// 构造函数
/// </summary>
/// <param name="image">待打印的图片对象</param>
public ImagePrintHelper(Image image) : this(image, "test.png")
/// <summary>
/// 构造函数
/// </summary>
/// <param name="image">待打印的图片对象</param>
/// <param name="documentname">文档名称</param>
public ImagePrintHelper(Image image, string documentname)
/// <summary>
/// 显示打印对话框，确定则进行打印
/// </summary>
/// <returns></returns>
public PrinterSettings PrintWithDialog()
/// <summary>
/// 在预览对话框中预览图片
/// </summary>
public void PrintPreview()
/// <summary>
/// 将在页面上居中打印输出。
/// </summary>
public bool AllowPrintCenter = true;
/// <summary>
/// 旋转图像，如果它符合页面更好
/// </summary>
public bool AllowPrintRotate = true;
/// <summary>
/// 缩放图像，以更好地适应页面
/// </summary>
public bool AllowPrintEnlarge = true;
/// <summary>
/// 允许打印收缩，以更好适应页面
/// </summary>
public bool AllowPrintShrink = true;
#endregion
/// <summary>
/// 构造函数
/// </summary>
/// <param name="image">待打印的图片对象</param>
public ImagePrintHelper(Image image) : this(image, "test.png")
/// <summary>
/// 构造函数
/// </summary>
/// <param name="image">待打印的图片对象</param>
/// <param name="documentname">文档名称</param>
public ImagePrintHelper(Image image, string documentname)
/// <summary>
/// 显示打印对话框，确定则进行打印
/// </summary>
/// <returns></returns>
public PrinterSettings PrintWithDialog()
/// <summary>
/// 在预览对话框中预览图片
/// </summary>
public void PrintPreview()
2）辅助类ImagePrintHelper的使用例子代码如下所示
private void btnPrintImage_Click(object sender, EventArgs e)
{
ImagePrintHelper imagePrint = new ImagePrintHelper(this.pictureBox1.Image, Path.GetFileName(this.txtFilPath.Text));
imagePrint.AllowPrintShrink = true;
imagePrint.AllowPrintCenter = true;
imagePrint.AllowPrintEnlarge = true;
imagePrint.AllowPrintRotate = true;
imagePrint.PrintWithDialog();//弹出打印对话框，确认进行打印
}
private void btnPrintView_Click(object sender, EventArgs e)
{
ImagePrintHelper imagePrint = new ImagePrintHelper(this.pictureBox1.Image, Path.GetFileName(this.txtFilPath.Text));
imagePrint.PrintPreview();//弹出打印预览页面
}
{
ImagePrintHelper imagePrint = new ImagePrintHelper(this.pictureBox1.Image, Path.GetFileName(this.txtFilPath.Text));
imagePrint.AllowPrintShrink = true;
imagePrint.AllowPrintCenter = true;
imagePrint.AllowPrintEnlarge = true;
imagePrint.AllowPrintRotate = true;
imagePrint.PrintWithDialog();//弹出打印对话框，确认进行打印
}
private void btnPrintView_Click(object sender, EventArgs e)
{
ImagePrintHelper imagePrint = new ImagePrintHelper(this.pictureBox1.Image, Path.GetFileName(this.txtFilPath.Text));
imagePrint.PrintPreview();//弹出打印预览页面
}
2、Web页面预览效果图片抓取辅助类 WebPageCapture和WebPreview
实现效果
1）本辅助类主要是用来方便实现Web页面预览效果图片抓取操作。
实现代码
1）辅助类提供的方法接口如下所示
#region 字段属性
/// <summary>
/// 图片下载完毕的时间处理
/// </summary>
public event ImageEventHandler DownloadCompleted;
/// <summary>
/// 图片处理委托定义
/// </summary>
/// <param name="image"></param>
public delegate void ImageEventHandler(Image image);
/// <summary>
/// 浏览区域大小
/// </summary>
public Size BrowserSize { get; set; }
/// <summary>
/// 页面URL地址
/// </summary>
public string URL { get; set; }
/// <summary>
/// 下载的图片对象
/// </summary>
public Image Image { get; private set; }
#endregion
#region 构造函数
/// <summary>
/// 构造函数,默认为屏幕大小
/// </summary>
public WebPageCapture() : this(Screen.PrimaryScreen.Bounds.Size) { }
/// <summary>
/// 构造函数，指定浏览区域大小
/// </summary>
/// <param name="width">宽度</param>
/// <param name="height">高度</param>
public WebPageCapture(int width, int height) : this(new Size(width, height)) { }
/// <summary>
/// 构造函数，指定浏览区域大小
/// </summary>
/// <param name="browserSize">浏览区域大小</param>
public WebPageCapture(Size browserSize)
#endregion
/// <summary>
/// 下载页面到图片中
/// </summary>
public void DownloadPage()
/// <summary>
/// 下载页面到图片中
/// </summary>
/// <param name="url">页面Url地址</param>
public void DownloadPage(string url)
2）辅助类WebPageCapture的使用例子代码如下所示
public partial class FrmWebPreview : Form
{
private WebPageCapture capture = new WebPageCapture();
public FrmWebPreview()
{
InitializeComponent();
capture.DownloadCompleted += new WebPageCapture.ImageEventHandler(capture_DownloadCompleted); }
void capture_DownloadCompleted(Image image)
{
this.pictureBox1.Image = image;
}
private void btnSnap1_Click(object sender, EventArgs e)
{
if (this.txtUrl.Text.Length == 0) return;
capture.DownloadPage(this.txtUrl.Text);
{
private WebPageCapture capture = new WebPageCapture();
public FrmWebPreview()
{
InitializeComponent();
capture.DownloadCompleted += new WebPageCapture.ImageEventHandler(capture_DownloadCompleted); }
void capture_DownloadCompleted(Image image)
{
this.pictureBox1.Image = image;
}
private void btnSnap1_Click(object sender, EventArgs e)
{
if (this.txtUrl.Text.Length == 0) return;
capture.DownloadPage(this.txtUrl.Text);
}
3） 辅助类WebPreview的使用例子代码如下所示
private void btnSnap2_Click(object sender, EventArgs e)
{
if (this.txtUrl.Text.Length == 0) return;
this.pictureBox1.Image = WebPreview.GetWebPreview(new Uri(this.txtUrl.Text), Screen.PrimaryScreen.Bounds.Size);
}
{
if (this.txtUrl.Text.Length == 0) return;
this.pictureBox1.Image = WebPreview.GetWebPreview(new Uri(this.txtUrl.Text), Screen.PrimaryScreen.Bounds.Size);
}
2、图片对象比较、缩放、缩略图、水印、压缩、转换、编码等操作辅助类 ImageHelper
实现效果
1）本辅助类主要是用来方便实现图片对象比较、缩放、缩略图、水印、压缩、转换、编码等操作。
2）基本图片所有的相关操作，均可在该辅助类中找到，该辅助类具有专业、全面、封装良好等特点。
实现代码
1）辅助类提供的方法接口如下所示
/// <summary>
/// 图片对象比较、缩放、缩略图、水印、压缩、转换、编码等操作辅助类
/// </summary>
public class ImageHelper
{
#region 图片比较
/// <summary>
/// 对比两张图片
/// </summary>
/// <param name="bmp1">The first bitmap image</param>
/// <param name="bmp2">The second bitmap image</param>
/// <returns>CompareResult</returns>
public static CompareResult CompareTwoImages(Bitmap bmp1, Bitmap bmp2)
#endregion
#region 图片缩放
/// <summary>
/// 按比例调整图片大小
/// </summary>
/// <param name="imgPhoto">原始图片对象.</param>
/// <param name="Percent">调整比例</param>
/// <returns></returns>
public static Image ResizeImageByPercent(Image imgPhoto, int Percent)
/// <summary>
/// 缩放、裁切图片
/// </summary>
/// <param name="originalImage">原始图片对象</param>
/// <param name="width">宽度</param>
/// <param name="height">高度</param>
/// <param name="mode">调整模式</param>
/// <returns></returns>
public static Image ResizeImageToAFixedSize(Image originalImage, int width, int height, ScaleMode mode)
#endregion
#region 创建缩略图
/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="originalImagePath">源图路径（物理路径）</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图高度</param>
/// <param name="mode">生成缩略图的方式</param>
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, ScaleMode mode)
/// <summary>
///
/// </summary>
public class ImageHelper
{
#region 图片比较
/// <summary>
/// 对比两张图片
/// </summary>
/// <param name="bmp1">The first bitmap image</param>
/// <param name="bmp2">The second bitmap image</param>
/// <returns>CompareResult</returns>
public static CompareResult CompareTwoImages(Bitmap bmp1, Bitmap bmp2)
#endregion
#region 图片缩放
/// <summary>
/// 按比例调整图片大小
/// </summary>
/// <param name="imgPhoto">原始图片对象.</param>
/// <param name="Percent">调整比例</param>
/// <returns></returns>
public static Image ResizeImageByPercent(Image imgPhoto, int Percent)
/// <summary>
/// 缩放、裁切图片
/// </summary>
/// <param name="originalImage">原始图片对象</param>
/// <param name="width">宽度</param>
/// <param name="height">高度</param>
/// <param name="mode">调整模式</param>
/// <returns></returns>
public static Image ResizeImageToAFixedSize(Image originalImage, int width, int height, ScaleMode mode)
#endregion
#region 创建缩略图
/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="originalImagePath">源图路径（物理路径）</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图高度</param>
/// <param name="mode">生成缩略图的方式</param>
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, ScaleMode mode)
/// <summary>
///