C#—打开文件

一、打开图片

ps：必须先在pictureBox中导入一张图片

private void button4_Click(object sender, EventArgs e)//选择、更换图片
{
     if (openFileDialog1.ShowDialog() == DialogResult.OK)//需要工具箱的openFileDialog
     {
         Text = openFileDialog1.FileName;//选择图片
       Bitmap map = (Bitmap)Image.FromFile(openFileDialog1.FileName);
          pictureBox1.Image = map;//更换图片
             
     }       
}

二、打开txt文档

        private void button5_Click(object sender, EventArgs e)//打开txt文档，仅限英文
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                StreamReader sr = new StreamReader(openFileDialog1.FileName);
                string line;
                while ((line = sr.ReadLine()) != null)
                {
                    listBox3.Items.Add(line);
                }
            }
        }