OpenFileDialog o = new OpenFileDialog();
o.InitialDirectory = AppDomain.CurrentDomain.BaseDirectory;
o.Title = "請選擇圖片";
o.Filter = "jpeg|*.jpeg|jpg|*.jpg|png|*.png|gif|*.gif";
if (o.ShowDialog() == DialogResult.OK)
{
picPath = o.FileName;//picPath在前面定義為string
try
{
Image bmp = Image.FromFile(picPath);//picPath為圖片路徑
Clipboard.SetDataObject(bmp);

DataFormats.Format dataFormat = DataFormats.GetFormat(DataFormats.Bitmap);
if (richText.CanPaste(dataFormat))//圖片展示在一個叫richText的richTextBox中
{
richText.Paste(dataFormat);
}

}
catch (Exception exc)
{
MessageBox.Show("圖片插入失敗。" + exc.Message, "提示",
MessageBoxButtons.OK, MessageBoxIcon.Information);
}

}
richText.Focus();
}
}

c# 點擊按選擇圖片然後展示在richTextBox中