【WPF學習手記】圖像動態播放並保存爲gif 動圖

本demo實現兩個目的：1. 圖片的循環播放； 2. 生成 gif 動圖；

思路：循環播放採用計時器；生成 gif 採用官方的函數，貌似只播放一次，不能循環播放。

• xaml代碼

<Window x:Class="GifSave.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:GifSave"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>
        <Border Name="border">
            <Image Name="image" Stretch="Uniform"/>
        </Border>
        <StackPanel Grid.Row="1" Orientation="Horizontal">
            <Button Name="btnStart" Content="Start" Margin="5" Click="Button_Click"/>
            <Button Name="btnPause" Content="Pause" Margin="5" Click="Button_Click"/>
            <Button Name="btnSave" Content="Save as gif" Margin="5" Click="Button_Click"/>
        </StackPanel>
    </Grid>
</Window>

• 後臺代碼

using System;
using System.IO;
using System.Threading;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using System.Windows.Threading;

namespace GifSave
{
    /// <summary>
    /// MainWindow.xaml 的交互邏輯
    /// </summary>
    public partial class MainWindow : Window
    {
        private bool isShowing = false;
        private int numberOfImage = 1;

        public MainWindow()
        {
            InitializeComponent();
        }

        private void ChangeImageSource(object sender, EventArgs e)
        {
            if (!isShowing)
            {
                return;
            }
            Dispatcher.BeginInvoke(DispatcherPriority.Normal,
                (ThreadStart)delegate ()
                {
                    image.Source = new BitmapImage(new Uri(@"C:\Users\Administrator\Desktop\魚\" + numberOfImage + ".jpg"));
                    numberOfImage = numberOfImage % 17 + 1;
                }
                );
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            if ((sender as Button).Name.ToString() == "btnStart")
            {
                isShowing = true;
                DispatcherTimer dispatcherTimer = new DispatcherTimer();
                dispatcherTimer.Tick += new EventHandler(ChangeImageSource);
                dispatcherTimer.Interval = new TimeSpan(0, 0, 0, 0, 250);
                dispatcherTimer.Start();
            }
            else if ((sender as Button).Name.ToString() == "btnPause")
            {
                isShowing = false;
            }
            else if ((sender as Button).Name.ToString() == "btnSave")
            {
                using (FileStream stream = new FileStream(@"C:\Users\Administrator\Desktop\魚\fish.gif", FileMode.Create))
                {
                    GifBitmapEncoder encoder = new GifBitmapEncoder();
                    for (int i = 1; i <= 17; i++)
                    {
                        encoder.Frames.Add(BitmapFrame.Create(new Uri(@"C:\Users\Administrator\Desktop\魚\" + (i % 17 + 1) + ".jpg")));
                    }
                    encoder.Save(stream);
                }
            }
        }
    }
}