WPF图片查看器
标签：oid visible orm false ott als 解决问题 mouse bottom
一、功能需求：
1、打开图片、打开文件夹；
2、下一张、上一张图片；
3、支持拖动、缩放、还原图片显示适当大小；
cs部分代码
1 ///
2 /// Interaction logic for ImageView.xaml
3 ///
4 public partial class ImageView : UserControl
5 {
6 public ImageView()
7 {
8 InitializeComponent();
9 }
10
11
12 bool mouseDown = false;
13 Point prePo;
14 private void Img_MouseDown(object sender, MouseButtonEventArgs e)
15 {
16 mouseDown = true;
17 Cursor = Cursors.Hand;
18 prePo = e.GetPosition(canvas);
19 }
20
21
22 ///
23 /// 移动图片
24 ///
25 ///
26 ///
27 private void Img_PreviewMouseMove(object sender, MouseEventArgs e)
28 {
29 Point currentPoint = e.GetPosition(canvas);
30 if (mouseDown)
31 {
32 double left = Canvas.GetLeft(img);
33 double top = Canvas.GetTop(img);
34 if (currentPoint.X != prePo.X)
35 Canvas.SetLeft(img, left + currentPoint.X - prePo.X);
36 if (currentPoint.Y != prePo.Y)
37 Canvas.SetTop(img, top + currentPoint.Y - prePo.Y);
38 prePo = currentPoint;
39 }
40 }
41
42 private void Img_MouseUp(object sender, MouseButtonEventArgs e)
43 {
44 mouseDown = false;
45 Cursor = Cursors.Arrow;
46 }
47
48 double scale = 1;
49 ///
50 /// 放大、缩小图片
51 ///
52 ///
53 ///
54 private void Img_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
55 {
56 double left = Canvas.GetLeft(img);
57 double top = Canvas.GetTop(img);
58 double preW = img.ActualWidth;
59 double preH = img.ActualHeight;
60
61 if (e.Delta > 0)
62 scale = scale + 0.01;
63 else
64 scale = scale - 0.01;
65 if (scale 0.01)
66 scale = 0.01;
67 img.RenderTransform = new ScaleTransform(scale, scale);
68 }
69
70 ///
71 /// 图片自适应显示
72 ///
73 ///
74 ///
75 private void BtnDefault_Click(object sender, RoutedEventArgs e)
76 {
77 scale = 1;
78 img.RenderTransform = new ScaleTransform(1, 1);
79 InitImage();
80 }
81
82 ///
83 /// 还原图片居中缩放适合尺寸显示
84 /// 当图片宽（高）大于高（宽）时，如果图片宽（高）超过显示区域宽（高）则进行缩放
85 /// 然后垂直水平居中
86 ///
87 void InitImage()
88 {
89 double areaH = canvas.ActualHeight;
90 double areaW = canvas.ActualWidth;
91 if (img.Width == 0) return;
92 if(img.Width > img.Height)
93 {
94 if (img.Width > areaW)
95 {
96 double scale = areaW / img.Width;
97 //img.RenderTransform = new ScaleTransform(scale, scale);
98 double scaleH = img.Height * scale;
99 Canvas.SetTop(img, (areaH - scaleH) / 2);
100 Canvas.SetLeft(img, 0);
101 img.Width = img.Width * scale;
102 img.Height = scaleH;
103 return;
104 }
105 Canvas.SetTop(img, (areaH - img.Height) / 2);
106 Canvas.SetLeft(img, (areaW - img.Width) / 2);
107 }
108 else
109 {
110 if (img.Height > areaH)
111 {
112 double scale = areaH / img.Height;
113 //img.RenderTransform = new ScaleTransform(scale, scale);
114 double scaleW = img.Width * scale;
115 Canvas.SetTop(img, 0);
116 Canvas.SetLeft(img, (areaW - scaleW) / 2);
117 img.Width = scaleW;
118 img.Height = img.Height * scale;
119 return;
120 }
121 Canvas.SetTop(img, (areaH - img.Height) / 2);
122 Canvas.SetLeft(img, (areaW - img.Width) / 2);
123 }
124 }
125
126 ///
127 /// 上一张
128 ///
129 ///
130 ///
131 private void BtnPreview_Click(object sender, RoutedEventArgs e)
132 {
133 if (images.Count 0) return;
134 index = --index 0 ? images.Count - 1 : index;
135 ChangeSelect(index);
136 }
137
138 ///
139 /// 下一张
140 ///
141 ///
142 ///
143 private void BtnNext_Click(object sender, RoutedEventArgs e)
144 {
145 if (images.Count 0) return;
146 index = ++index >= images.Count ? 0 : index;
147 ChangeSelect(index);
148 }
149
150 ///
151 /// 打开图片
152 ///
153 ///
154 ///
155 private void BtnImage_Click(object sender, RoutedEventArgs e)
156 {
157 System.Windows.Forms.OpenFileDialog fileDialog = new System.Windows.Forms.OpenFileDialog();
158 fileDialog.Title = "请选择图片文件";
159 fileDialog.Filter = filter;
160 fileDialog.RestoreDirectory = true;
161 if(fileDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
162 {
163 tbNotice.Visibility = Visibility.Collapsed;
164 if (fileDialog.FileNames.Length > 1)
165 LoadImages(fileDialog.FileNames);
166 else
167 LoadFolder(System.IO.Path.GetDirectoryName(fileDialog.FileName), fileDialog.FileName);
168 }
169 }
170
171 int index = 0;
172 string folder = null;
173 Liststring> images = new Liststring>();
174 string filter = "图像文件|*.png;*.jpg;*.jpeg;*.bmp";
175 ///
176 /// 打开文件夹
177 ///
178 ///
179 ///
180 private void BtnFolder_Click(object sender, RoutedEventArgs e)
181 {
182 System.Windows.Forms.FolderBrowserDialog folderBrowser = new System.Windows.Forms.FolderBrowserDialog();
183 folderBrowser.Description = "请选择图片目录";
184 if (folderBrowser.ShowDialog() == System.Windows.Forms.DialogResult.OK)
185 {
186 tbNotice.Visibility = Visibility.Collapsed;
187 folder = folderBrowser.SelectedPath;
188 LoadFolder(folder);
189 }
190 }
191
192 ///
193 /// 切换当前图片
194 ///
195 ///
196 void ChangeSelect(int select)
197 {
198 if (select 0 || images.Count 1)
199 return;
200 if (select >= images.Count)
201 select = images.Count - 1;
202
203 string file = images[select];
204 ChangeSelect(file);
205 }
206
207 ///
208 /// 切换当前图片
209 ///
210 ///
211 void ChangeSelect(string select)
212 {
213 tbName.Text = System.IO.Path.GetFileName(select);
214 if (!File.Exists(select))
215 {
216 int i = images.IndexOf(select);
217 images.Remove(select);
218 MessageBox.Show("图片丢失");
219 if (images.Count 0)
220 tbNotice.Visibility = Visibility.Visible;
221 else
222 ChangeSelect(i);
223 return;
224 }
225 BitmapImage bitmap = new BitmapImage(new Uri(select));
226 img.Source = bitmap;
227 img.Width = bitmap.PixelWidth;
228 img.Height = bitmap.Height;
229 InitImage();
230 }
231
232 ///
233 /// 加载文件到集合中
234 ///
235 ///
236 void LoadImages(string[] files)
237 {
238 images.Clear();
239 images.AddRange(files);
240 index = 0;
241 ChangeSelect(index);
242 }
243
244 ///
245 /// 加载目录图片到集合中
246 ///
247 ///
248 ///
249 void LoadFolder(string folder, string select = null)
250 {
251 images.Clear();
252 string[] files = Directory.GetFiles(folder);
253 if (files == null)
254 return;
255 foreach (var item in files)
256 {
257 if (filter.Contains(System.IO.Path.GetExtension(item.ToLowerInvariant())))
258 images.Add(item);
259 }
260 index = 0;
261 ChangeSelect(select ?? images[0]);
262 }
263 }
View Code
xaml部分代码：
UserControl x:Class="MahAppsMetro.Demo.Views.ImageView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MahAppsMetro.Demo.Views"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
Grid>
Canvas x:Name="canvas" Background="Beige">
Image x:Name="img" Canvas.Top="0" Canvas.Left="0"
MouseDown="Img_MouseDown" PreviewMouseMove="Img_PreviewMouseMove" MouseUp="Img_MouseUp" PreviewMouseWheel="Img_PreviewMouseWheel" />
Canvas>
TextBlock x:Name="tbNotice" Text="请选择图片" VerticalAlignment="Center" HorizontalAlignment="Center" />
TextBlock x:Name="tbName" HorizontalAlignment="Center" Margin="20" />
WrapPanel HorizontalAlignment="Center" VerticalAlignment="Bottom" Margin="20">
Button x:Name="btnImage" Content="打开" Width="40" Height="20" VerticalAlignment="Bottom" Background="Transparent" BorderThickness="1"
Click="BtnImage_Click" />
Button x:Name="btnFolder" Content="文件夹" Width="40" Height="20" VerticalAlignment="Bottom" Background="Transparent" BorderThickness="1"
Click="BtnFolder_Click"/>
Button x:Name="btnPreview" Content="上一张" Width="40" Height="20" VerticalAlignment="Bottom" Background="Transparent" BorderThickness="1"
Click="BtnPreview_Click" />
Button x:Name="btnDefault" Content="适应" Width="40" Height="20" VerticalAlignment="Bottom" Background="Transparent" BorderThickness="1"
Click="BtnDefault_Click" Canvas.Left="378" Canvas.Bottom="20"/>
Button x:Name="btnNext" Content="下一张" Width="40" Height="20" VerticalAlignment="Bottom" Background="Transparent" BorderThickness="1"
Click="BtnNext_Click" />
WrapPanel>
Grid>
UserControl>
效果：
待解决问题：拖动后释放鼠标有时没有释放状态
WPF图片查看器
标签：oid visible orm false ott als 解决问题 mouse bottom
原文地址：https://www.cnblogs.com/RedSky/p/10084170.html
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WPF图片查看器
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