龙年新作：水印文字添加工具源码摘要

下载地址：http://www.xdowns.com/soft/31/93/2012/Soft_84985.html

源码要点核心：生成添加水印文字后的图片。

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace ImageProc
{
    public class WaterText
    {
        /// <summary>
        /// 生成添加水印后的图象。
        /// </summary>
        /// <param name="src">用于在其上添加水印的源图象，一个ImageSource的子类的对象。</param>
        /// <param name="rect">一个Rect结构，表示要生成的图象的大小。</param>
        /// <param name="test">水印文本。</param>
        /// <param name="fontFamily">使用的字体名称，如宋体等。</param>
        /// <param name="fontSize">字体大小。</param>
        /// <param name="DpiX">要生成的图象的水平分辨率（建议96以上）。</param>
        /// <param name="DpiY">要生成的图象的垂直分辨率（建议96以上）。</param>
        /// <param name="PaddingH">水平边距。</param>
        /// <param name="PaddingV">垂直边距。</param>
        /// <param name="loca">水印在图象中的位置，一个WaterLocation枚举。</param>
        /// <param name="wcolor">水印文字的颜色。</param>
        /// <param name="IsBold">水印文字是否加粗。</param>
        /// <param name="IsItalic">水印文是否倾斜。</param>
        /// <returns>一个ImageSource实例，表示处理后的图象。</returns>
        public BitmapSource BuildIamge(BitmapSource src, Rect rect, string test, string fontFamily, double fontSize,
                double DpiX, double DpiY, double PaddingH, double PaddingV, WaterLocation loca, Color wcolor,
                bool IsBold, bool IsItalic)
        {
            DrawingVisual drv = new DrawingVisual();
            // 通过DrawingVisual的RenderOpen方法返回一个DrawingContext
            using (DrawingContext dc = drv.RenderOpen())
            {
                // 绘制图象
                dc.DrawImage(src, rect);
                // 设置文字
                FontFamily fontf = new FontFamily(fontFamily);
                FontStyle MyFontStyle = IsItalic == true ? FontStyles.Italic : FontStyles.Normal;
                FontWeight MyFontWeight = IsBold == true ? FontWeights.Bold : FontWeights.Normal;
                Typeface tface = new Typeface(fontf, MyFontStyle, MyFontWeight, FontStretches.Normal);
                SolidColorBrush cb = new SolidColorBrush(wcolor);
                FormattedText ft = new FormattedText(
                    test,
                    System.Globalization.CultureInfo.CurrentCulture,
                    FlowDirection.LeftToRight,
                    tface,
                    fontSize,
                    cb);

                // 确定文本的位置
                double newX = 0, newY = 0;
                TextAlignment MyAlignment = TextAlignment.Left;
                switch (loca)
                {
                    case WaterLocation.TopLeft:
                        newX = PaddingH;
                        newY = PaddingV;
                        MyAlignment = TextAlignment.Left;
                        break;
                    case WaterLocation.TopCenter:
                        newX = PaddingH;
                        newY = PaddingV;
                        MyAlignment = TextAlignment.Center;
                        break;
                    case WaterLocation.TopRight:
                        newX = PaddingH;
                        newY = PaddingV;
                        MyAlignment = TextAlignment.Right;
                        break;
                    case WaterLocation.MidLeft:
                        newX = PaddingH;
                        newY = ((rect.Height - PaddingV * 2) - ft.Height) / 2;
                        MyAlignment = TextAlignment.Left;
                        break;
                    case WaterLocation.MidCenter:
                        newX = PaddingH;
                        newY = ((rect.Height - PaddingV * 2) - ft.Height) / 2;
                        MyAlignment = TextAlignment.Center;
                        break;
                    case WaterLocation.MidRight:
                        newX = PaddingH;
                        newY = ((rect.Height - PaddingV * 2) - ft.Height) / 2;
                        MyAlignment = TextAlignment.Right;
                        break;
                    case WaterLocation.BottomLeft:
                        newX = PaddingH;
                        newY = rect.Height - PaddingV - ft.Height;
                        MyAlignment = TextAlignment.Left;
                        break;
                    case WaterLocation.BottomCenter:
                        newX = PaddingH;
                        newY = rect.Height - PaddingV - ft.Height;
                        MyAlignment = TextAlignment.Center;
                        break;
                    case WaterLocation.BottomRight:
                        newX = PaddingH;
                        newY = rect.Height - PaddingV - ft.Height;
                        MyAlignment = TextAlignment.Right;
                        break;
                    default:
                        break;
                }

                ft.MaxTextWidth = rect.Width - 2 * PaddingH;
                ft.TextAlignment = MyAlignment;
                // 绘制文字
                dc.DrawText(ft, new Point(newX, newY));
            }

            RenderTargetBitmap rdb = new RenderTargetBitmap(
                src.PixelWidth,
                src.PixelHeight,
                DpiX, DpiY, PixelFormats.Default);

            // 通过该方法呈现可视化对象。
            rdb.Render(drv);
            return rdb;
        }

    }

    /// <summary>
    /// 水印的位置
    /// </summary>
    public enum WaterLocation
    {
        /// <summary>
        /// 左上角
        /// </summary>
        TopLeft,
        /// <summary>
        /// 顶部居中
        /// </summary>
        TopCenter,
        /// <summary>
        /// 右上角
        /// </summary>
        TopRight,
        /// <summary>
        /// 中部居左
        /// </summary>
        MidLeft,
        /// <summary>
        /// 中部居中
        /// </summary>
        MidCenter,
        /// <summary>
        /// 中部居右
        /// </summary>
        MidRight,
        /// <summary>
        /// 左下角
        /// </summary>
        BottomLeft,
        /// <summary>
        /// 底部居中
        /// </summary>
        BottomCenter,
        /// <summary>
        /// 右下角
        /// </summary>
        BottomRight
    }
}

源码要点1：初始屏幕中的按钮，在打开图片前显示，存在已打开图片后隐藏，类似QQ影音。

这里自定义了一个转换器，如果Image的Source属性为null，则按钮的Visibility属性为Visible，否则为Collapsed。

     /// <summary>
    /// 类型转换器
    /// </summary>
    [ValueConversion(typeof(ImageSource), typeof(Visibility))]
    public class VisibleConvert : IValueConverter
    {

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value == null)
            {
                return Visibility.Visible;
            }
            else
            {
                return Visibility.Collapsed;
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            return null;
        }

    }

接着，把这个转换器用到Binding中，对按钮进行绑定。

            Binding myBinding = new Binding();
            myBinding.Path = new PropertyPath(Image.SourceProperty);
            myBinding.Converter = new VisibleConvert();
            myBinding.Source = this.img;
            myBinding.Mode = BindingMode.OneWay;
            BindingOperations.SetBinding(btnOpenBig, Button.VisibilityProperty, myBinding);

源码要点2：“打开”和“保存”对话框。

WPF中没有这些对话框组件，但是，我们不要忘了，在WinForm里面，有OpenFileDialog类和SaveFileDialog类。

但是，System.Windows.Forms命名空间下，个别类型的名字与System.Windows命名空间下的类型名字相同，也就是说，WinForm中用到的许多类和WPF中的类名字相同，但它们是不同逻辑的，所以，在引入命名空间的时候，应当使用别名，这样在代码中使用的时候就不会发生冲突了。

using DW = System.Drawing;
using WF = System.Windows.Forms;
using IO = System.IO;

所以，在保存文件的时候，我们可以这样写代码。

            WF.SaveFileDialog saveDlg = new WF.SaveFileDialog();
            int MyIndex = this.cmbFormat.SelectedIndex;
            saveDlg.Title = "保存文件";
            BitmapEncoder MyEncoder = null;
            switch (MyIndex)
            {
                case 0:
                    saveDlg.FileName = @"outPut.jpg";
                    MyEncoder = new JpegBitmapEncoder();
                    break;
                case 1:
                    saveDlg.FileName = @"outPut.bmp";
                    MyEncoder = new BmpBitmapEncoder();
                    break;
                case 2:
                    saveDlg.FileName = @"outPut.png";
                    MyEncoder = new PngBitmapEncoder();
                    break;
                default:
                    saveDlg.FileName = @"outPut.jpg";
                    MyEncoder = new JpegBitmapEncoder();
                    break;
            }
            if (saveDlg.ShowDialog() == WF.DialogResult.OK)
            {
                string fileName = saveDlg.FileName;
                try
                {
                    using (IO.FileStream fs = IO.File.Open(fileName, IO.FileMode.OpenOrCreate, IO.FileAccess.Write))
                    {
                        MyEncoder.Frames.Add(BitmapFrame.Create((BitmapSource)this.img.Source));
                        MyEncoder.Save(fs);
                        fs.Close();
                    }
                    MessageBox.Show("保存成功。", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
                }
            }

源码要点3：如何取得程序标题和版本号。

程序标题栏上的文字是在运行后动态生成的，可以通过反射技术，在窗口类构造函数中设置。

我们先为窗口类定义两个公共属性，分别用来取得程序标题和版本号。

         /// <summary>
        /// 程序标题
        /// </summary>
        public string TitleText
        {
            get
            {
                object[] objs = Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(AssemblyTitleAttribute), false);
                if (objs.Length > 0)
                {
                    AssemblyTitleAttribute attr = (AssemblyTitleAttribute)objs[0];
                    return attr.Title;
                }
                return string.Empty;
            }
        }

        /// <summary>
        /// 返回程序版本
        /// </summary>
        public string AppVersion
        {
            get
            {
                string ver = Assembly.GetExecutingAssembly().GetName().Version.ToString();
                if (ver != "")
                {
                    return ver;
                }
                return string.Empty;
            }
        }