Question

我刚开始学习c＃两个月前，我得到了当前项目（windows窗体）的代码来设置背景图片：

    public FormMain()
    {
        this.BackgroundImage = Properties.Resources.image;
        InitializeComponent();
        var timer = new Timer();
        ////change the background image every second  
        timer.Interval = 1000;
        timer.Tick += new EventHandler(timer_Tick);
        timer.Start();
    }

    void timer_Tick(object sender, EventArgs e)
    {
        //add image in list from resource file.  
        List<Bitmap> lisimage = new List<Bitmap>();
        lisimage.Add(Properties.Resources.image);
        var indexbackimage = DateTime.Now.Second % lisimage.Count;
        this.BackgroundImage = lisimage[indexbackimage];
    }

我的问题是：你是否必须每秒更换背景图像，或者如果我只是写（我只有一个背景图像）就足够了：

public FormMain()
{
    this.BackgroundImage = Properties.Resources.image;
    InitializeComponent();
}

因为它似乎有效。

Answer 1

如果要迭代一系列图像以创建动画，则只需要这样的计时器。

你所拥有的就足以设置一次图像。

Answer 2

正如AaronLS所写，设置背景一次就足够了。我更进一步解释为什么你所拥有的额外代码没有多大意义（假设这是整个代码）。

void timer_Tick(object sender, EventArgs e)
{
    //add image in list from resource file.  
    List<Bitmap> lisimage = new List<Bitmap>(); //this line creates a new list
    lisimage.Add(Properties.Resources.image); //fill the NEWLY created list with the one image from the resources
    //note, that resources are usually static, so it's always the same resource
    var indexbackimage = DateTime.Now.Second % lisimage.Count; //choose an index from the list, but the list only contains that one image, so the index will always be 0
    this.BackgroundImage = lisimage[indexbackimage]; //pick the same image that was set initially
}

正如您所看到的，代码相当荒谬 - 它没有做任何事情。它看起来有人想创建一种每秒切换图像的机制，但即使这样也很难编码。

你必须每秒更改背景图像吗？

2 个答案: