C#中上传图片按比例自动缩小或放大

/**//// <summary>


/// 按比例缩小图片，自动计算宽度


/// </summary>


/// <param name="strOldPic">源图文件名(包括路径)</param>


/// <param name="strNewPic">缩小后保存为文件名(包括路径)</param>


/// <param name="intHeight">缩小至高度</param>


public void SmallPicWidth(string strOldPic, string strNewPic, int intHeight)




...{


System.Drawing.Bitmap objPic, objNewPic;


try




...{


objPic = new System.Drawing.Bitmap(strOldPic);


int intWidth = (intHeight / objPic.Height) * objPic.Width;


objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);


objNewPic.Save(strNewPic);


}




catch (Exception exp) ...{ throw exp; }


finally




...{


objPic = null;


objNewPic = null;


}


}




/**//// <summary>


/// 缩小图片


/// </summary>


/// <param name="strOldPic">源图文件名(包括路径)</param>


/// <param name="strNewPic">缩小后保存为文件名(包括路径)</param>


/// <param name="intWidth">缩小至宽度</param>


/// <param name="intHeight">缩小至高度</param>


public void SmallPic(string strOldPic, string strNewPic, int intWidth, int intHeight)




...{


System.Drawing.Bitmap objPic, objNewPic;


try




...{


objPic = new System.Drawing.Bitmap(strOldPic);


objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);


objNewPic.Save(strNewPic);


}


catch (Exception exp)




...{ throw exp; }


finally




...{


objPic = null;


objNewPic = null;


}


}