[英]Failed to convert parameter value from a String to a Byte[]
净代码,当我尝试以二进制格式插入字符串时遇到此问题。
我在decal.DecalLogoFileName和decal.DecalLogoFileName中有图像的二进制格式,它定义了一个字符串,所以当我尝试
cmd.Parameters.Add(new SqlParameter("@DecalLogoFileName", SqlDbType.Binary)).Value=decal.DecalLogoFileName;
decal.DecalLogoFileName="data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wCEAAkGBxITEhUTExIWFhUXGB8aGBcYGR0ZHxobGhoXHRcYGBkaHyghHRolHRcXIjEhJSkrLi4uGB8zODMtNygtLisBCgoKDg0OGhAQGy0lHyUtLS0tLS0tLS0tLS0tLy0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLSstLS0tLS0tLS0tLf/AABEIALcBEwMBIgACEQEDEQH/xAAbAAACAwEBAQAAAAAAAAAAAAAEBQIDBgABB//EAEgQAAIBAgQDBQQHBQYDCAMAAAECEQADBBIhMQVBUQYTImFxMoGRoSNCUrHB0fAUcpLS4QczU2KCshVUc0Njg5OiwuLxFiRk/8QAGQEAAwEBAQAAAAAAAAAAAAAAAQIDAAQF/8QALBEAAgICAgECBQQCAwAAAAAAAAECERIhAzFBE2EiMlFxgUKhsdEEkSMzUv/aAAwDAQACEQMRAD8A"
我是贴花的字符串值
function readURL(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
$('#DecalLogo').attr('src', e.target.result);
$('#hdImageName').val(e.target.result);
}
reader.readAsDataURL(input.files[0]);
}
}
这里hdImageName值存储在decal.DecalLogoFileName中
我也尝试过
cmd.Parameters.Add(new SqlParameter("@DecalLogoFileName", SqlDbType.Binary)).Value=Convert.toByte(decal.DecalLogoFileName);
但是转换问题来了。
DecalLogoFileName的列数据类型设置为varbinary(MAX)
这样尝试;
var byteArray = Encoding.ASCII.GetBytes(decal.DecalLogoFileName);
cmd.Parameters.Add(new SqlParameter("@DecalLogoFileName", SqlDbType.VarBinary, byteArray.Length)).Value=byteArray;
要从数据库检索图像,可以使用Encoding.ASCII.GetString(byteArray)
将其转换为base64字符串。 然后您可以像这样将图像放在img src中;
<img src="data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wCEAAkGBxITEhUTExIWFhUXGB8aGBcYGR0ZHxobGhoXHRcYGBkaHyghHRolHRcXIjEhJSkrLi4uGB8zODMtNygtLisBCgoKDg0OGhAQGy0lHyUtLS0tLS0tLS0tLS0tLy0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLSstLS0tLS0tLS0tLf/AABEIALcBEwMBIgACEQEDEQH/xAAbAAACAwEBAQAAAAAAAAAAAAAEBQIDBgABB//EAEgQAAIBAgQDBQQHBQYDCAMAAAECEQADBBIhMQVBUQYTImFxMoGRoSNCUrHB0fAUcpLS4QczU2KCshVUc0Njg5OiwuLxFiRk/8QAGQEAAwEBAQAAAAAAAAAAAAAAAQIDAAQF/8QALBEAAgICAgECBQQCAwAAAAAAAAECERIhAzFBE2EiMlFxgUKhsdEEkSMzUv/aAAwDAQACEQMRAD8A"
alt="SampleImage" />
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