c# - 从表中读取二进制数据

Question

我有 PostgreSQL 9.2，有这张表：

CREATE TABLE "Task"
(
  "taskID" serial NOT NULL,
  "taskType" text NOT NULL,
  "taskComment" text NOT NULL,
  "taskDate" date NOT NULL,
  "taskeImage" bytea,
  CONSTRAINT "Task_pkey" PRIMARY KEY ("taskID")
)

该表已被记录填充。我只想阅读taskeImage并在pictureBox1.

这是我的尝试：

//some initial code goes here
NpgsqlDataReader dr = command.ExecuteReader();
dr.Read();
pictureBox1.Image=dr[4];
conn.Close();

Answer 1

PictureBox.Image是 Image 类型，dr[4]可能会返回一个byte[]. 您需要从原样创建图像byte []：

using (MemoryStream ms = new MemoryStream((byte[])dr[4]))
{
    pictureBox1.Image= Image.FromStream(ms);
}