绘制边框图像列表视图 [英] Draw border for image in listview

问题描述

在选择事件发生后一个TreeView，我填充图像的列表视图。
我想自定义格式这些图像，并将黑色边框每个图像。

 私人无效TreeView1_Select（对象发件人，EventArgs的）{
        如果（文件夹= NULL和放大器;！＆安培; System.IO.Directory.Exists（文件夹））{

            DirectoryInfo的DIR =新的DirectoryInfo（@folder）;
            的foreach（在dir.GetFiles的FileInfo文件（））{
                尝试 {
                    imageList.Images.Add（Image.FromFile（file.FullName））;
                } 抓住 {
                    Console.WriteLine（这不是一个图像文件）;
                }
            }

            对于（INT J = 0; J＆LT; imageList.Images.Count; J ++）{
                this.ListView1.Items.Add（项目+ J）;
                this.ListView1.Items [J] .ImageIndex = j的;
            }

            this.ListView1.View = View.LargeIcon;
            this.ListView1.LargeImageList =图像列表;
            this.ListView1.DrawItem + =
                新DrawListViewItemEventHandler（ListView1_DrawItem）;

        }
    }

    私人无效ListView1_DrawItem（对象发件人，DrawListViewItemEventArgs E）
    {

    }
 

解决方案

我会使用图形对象立即从文件加载图像后添加边框：

修改：修改了code，这对我的作品......

 私人无效TreeView1_Select（对象发件人，EventArgs的）{
        如果（文件夹= NULL和放大器;！＆安培; System.IO.Directory.Exists（文件夹））{

            DirectoryInfo的DIR =新的DirectoryInfo（@folder）;
            的foreach（在dir.GetFiles的FileInfo文件（））{

                图片IMG =新位图（Image.FromFile（file.FullName））;
                使用（图形G = Graphics.FromImage（IMG））{
                    g.DrawRectangle（Pens.Black，0，0，img.Width  -  2，img.Height  -  2）;
                }
                imageList.Images.Add（IMG）;
 

注意：图像复制的目的;如果我修改code到

 图片IMG =（位图）Bitmap.FromFile（test.bmp）;
 

作为评论的建议，我得到一个异常说图形对象不能从具有索引像素格式的图像创建。

On a treeview after the select event, I populate a listview with images.
I want to custom format these images and place a black color border around each image.

   private void TreeView1_Select(object sender, EventArgs e) {
        if (folder != null && System.IO.Directory.Exists(folder)) {

            DirectoryInfo dir = new DirectoryInfo(@folder);
            foreach (FileInfo file in dir.GetFiles()) {
                try {
                    imageList.Images.Add(Image.FromFile(file.FullName));
                } catch {
                    Console.WriteLine("This is not an image file");
                }
            }

            for (int j = 0; j < imageList.Images.Count; j++) {
                this.ListView1.Items.Add("Item" + j);
                this.ListView1.Items[j].ImageIndex = j;
            }

            this.ListView1.View = View.LargeIcon;
            this.ListView1.LargeImageList = imageList;
            this.ListView1.DrawItem += 
                new DrawListViewItemEventHandler(ListView1_DrawItem);

        }
    }

    private void ListView1_DrawItem(object sender, DrawListViewItemEventArgs e) 
    {

    }

解决方案

I would add a border using a Graphics object immediately after loading the images from file:

EDIT: modified the code, this works for me...

    private void TreeView1_Select(object sender, EventArgs e) {
        if (folder != null && System.IO.Directory.Exists(folder)) {

            DirectoryInfo dir = new DirectoryInfo(@folder);
            foreach (FileInfo file in dir.GetFiles()) {

                Image img = new Bitmap(Image.FromFile(file.FullName));
                using (Graphics g = Graphics.FromImage(img)){
                    g.DrawRectangle(Pens.Black, 0, 0, img.Width - 2, img.Height - 2);
                }
                imageList.Images.Add(img);

NOTE: the image copying is intended; if I modify the code to

    Image img = (Bitmap)Bitmap.FromFile("test.bmp");

as suggested in the comments, I get an exception saying "A Graphics object cannot be created from an image that has an indexed pixel format."

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