私のユーティリティは、.jpg または .png ファイルのサイズを変更することになっています。
1 つの場所 (IrfanView がインストールされていない職場) では問題なく動作するようです。しかし、自宅で *.jpg を開いて保存 (サイズ変更) すると、次のように表示されます。
ただし、どちらの場合でも（ダイアログで「はい」または「いいえ」を選択しても、画像は正常に表示されます。
IOW、私はjpgとpngの両方を読み込んで保存することができ、それらはそのまま保存され、正常に表示されます。しかし、IrfanView は、それらが台無しになっていると主張しています。
実際、画像がどのように保存されているかはわかりません。拡張子に基づいて「舞台裏で」適切な形式で保存しただけだと思っていました。とにかく、これはかなり単純なユーティリティなので、すべてのコードを示します。
using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
namespace FileResizingUtil
{
public partial class FormFileResizer : Form
{
private Image _imgToResize;
String _originalFilename = String.Empty;
public FormFileResizer()
{
InitializeComponent();
}
private void buttonChooseImage_Click(object sender, EventArgs e)
{
OpenFileDialog ofd = new OpenFileDialog
{
InitialDirectory = "c:\\",
Filter = "JPG files (*.jpg)|*.jpg| PNG files (*.png)|*.png", FilterIndex = 2, RestoreDirectory = true
};
if (ofd.ShowDialog() == DialogResult.OK)
{
try
{
_originalFilename = ofd.FileName;
_imgToResize = Image.FromFile(_originalFilename);
}
catch (Exception ex)
{
MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
}
}
// If made it to here, it must be good
String preamble = labelImgSelected.Text;
labelImgSelected.Text = String.Format("{0}{1}", preamble, _originalFilename);
textBoxOrigHeight.Text = _imgToResize.Height.ToString();
textBoxOrigWidth.Text = _imgToResize.Width.ToString();
buttonApplyPercentageChange.Enabled = true;
//buttonResizeImage.Enabled = true;
}
private void buttonResizeImage_Click(object sender, EventArgs e)
{
// Really large images take awhile, so show an hourglass
Cursor.Current = Cursors.WaitCursor;
try
{
var size = new Size { Height = Convert.ToInt32(textBoxNewHeight.Text), Width = int.Parse(textBoxNewWidth.Text) };
// Two different ways of getting the int val
Image resizedImg = FileResizeUtils.GetResizedImage(_imgToResize, size);
String fileNameSansExtension = Path.GetFileNameWithoutExtension(_originalFilename);
String fileNameExtension = Path.GetExtension(_originalFilename);
String newFilename = String.Format("{0}{1}_{2}{3}", fileNameSansExtension, size.Height, size.Width, fileNameExtension);
// If used a different extension (jpg where the original was png, or vice versa) would the Save be intelligent enough to actually save in the other format?
resizedImg.Save(newFilename);
MessageBox.Show(String.Format("Done! File saved as {0}", newFilename));
Recycle();
}
finally
{
Cursor.Current = Cursors.Default;
}
}
private void Recycle()
{
buttonResizeImage.Enabled = false;
buttonApplyPercentageChange.Enabled = false;
labelImgSelected.Text = "Image selected: ";
textBoxOrigHeight.Text = String.Empty;
textBoxOrigWidth.Text = String.Empty;
// Retain the percentage vals, as it may be that all in a batch need to be the same pair of vals
}
private void buttonApplyPercentageChange_Click(object sender, EventArgs e)
{
int origHeight = _imgToResize.Height;
int origWidth = _imgToResize.Width;
// Two ways to convert the val
double heightFactor = (double)numericUpDownHeight.Value / 100.0;
double widthFactor = Convert.ToDouble(numericUpDownWidth.Value) / 100.0;
if (heightFactor < 0 || widthFactor < 0)
{
// show an error - no negative values allowed- using updown, so that should not be possible
}
var newHeight = Convert.ToInt32(origHeight * heightFactor);
var newWidth = Convert.ToInt32(origWidth * widthFactor);
textBoxNewHeight.Text = newHeight.ToString();
textBoxNewWidth.Text = newWidth.ToString();
buttonResizeImage.Enabled = true;
}
private void textBoxNewHeight_TextChanged(object sender, EventArgs e)
{
EnableResizeButtonIfValidDimensionsEntered();
}
private void EnableResizeButtonIfValidDimensionsEntered()
{
if (String.IsNullOrWhiteSpace(textBoxOrigHeight.Text)) return;
String candidateHeight = textBoxNewHeight.Text;
String candidateWidth = textBoxNewWidth.Text;
int validHeight;
int validWidth;
buttonResizeImage.Enabled = (int.TryParse(candidateHeight, out validHeight)) &&
(int.TryParse(candidateWidth, out validWidth));
}
private void numericUpDownHeight_ValueChanged(object sender, EventArgs e)
{
if (checkBoxRetainRatio.Checked)
{
numericUpDownWidth.Value = numericUpDownHeight.Value;
}
}
private void numericUpDownWidth_ValueChanged(object sender, EventArgs e)
{
if (checkBoxRetainRatio.Checked)
{
numericUpDownHeight.Value = numericUpDownWidth.Value;
}
}
}
}
..そしてGUI（「画像のサイズ変更」ボタンを押す直前：
アップデート
Eugene Sh.'ls のコメントに基づいて、Save メソッドを次のブロックに変更しました。
bool success = true;
. . .
if (fileNameExtension != null && fileNameExtension.ToLower().Contains("jpg"))
{
resizedImg.Save(newFilename, ImageFormat.Jpeg);
}
else if (fileNameExtension != null &&
fileNameExtension.ToLower().Contains("png"))
{
resizedImg.Save(newFilename, ImageFormat.Png);
}
else
{
success = false;
}
if (success)
{
MessageBox.Show(String.Format("Done! File saved as {0}", newFilename));
}
else
{
MessageBox.Show("Something went awry. The file was not saved");
}
更新 2
したがって、提案を実装し、いくつかの新しいファイルタイプをサポートする私の新しいコードは次のとおりです。
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Forms;
namespace FileResizingUtil
{
public partial class FormFileResizer : Form
{
private Image _imgToResize;
String _originalFilename = String.Empty;
public FormFileResizer()
{
InitializeComponent();
}
private void buttonChooseImage_Click(object sender, EventArgs e)
{
OpenFileDialog ofd = new OpenFileDialog
{
InitialDirectory = "c:\\",
Filter = "JPG files (*.jpg)|*.jpg| PNG files (*.png)|*.png| BMP files (*.bmp)|*.bmp| TIFF files (*.tiff)|*.png| ICO files (*.ico)|*.ico| EMF files (*.emf)|*.emf| WMF files (*.wmf)|*.wmf",
FilterIndex = 1, RestoreDirectory = true
};
if (ofd.ShowDialog() == DialogResult.OK)
{
try
{
_originalFilename = ofd.FileName;
_imgToResize = Image.FromFile(_originalFilename);
}
catch (Exception ex)
{
MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
}
}
if (String.IsNullOrWhiteSpace(_originalFilename)) return;
// If made it to here, it must be good
String preamble = labelImgSelected.Text;
labelImgSelected.Text = String.Format("{0}{1}", preamble, _originalFilename);
textBoxOrigHeight.Text = _imgToResize.Height.ToString();
textBoxOrigWidth.Text = _imgToResize.Width.ToString();
buttonApplyPercentageChange.Enabled = true;
}
private void buttonResizeImage_Click(object sender, EventArgs e)
{
bool success = true;
// Really large images take awhile, so show an hourglass
Cursor.Current = Cursors.WaitCursor;
try
{
// Two different ways of getting the int val
var size = new Size { Height = Convert.ToInt32(textBoxNewHeight.Text), Width = int.Parse(textBoxNewWidth.Text) };
Image resizedImg = FileResizeUtils.GetResizedImage(_imgToResize, size);
String fileNameSansExtension = Path.GetFileNameWithoutExtension(_originalFilename);
String fileNameExtension = Path.GetExtension(_originalFilename);
String newFilename = String.Format("{0}{1}_{2}{3}", fileNameSansExtension, size.Height, size.Width, fileNameExtension);
if (fileNameExtension != null && fileNameExtension.ToLower().Contains("jpg"))
{
resizedImg.Save(newFilename, ImageFormat.Jpeg);
}
else if (fileNameExtension != null && fileNameExtension.ToLower().Contains("png"))
{
resizedImg.Save(newFilename, ImageFormat.Png);
}
else if (fileNameExtension != null && fileNameExtension.ToLower().Contains("bmp"))
{
resizedImg.Save(newFilename, ImageFormat.Bmp);
}
else if (fileNameExtension != null && fileNameExtension.ToLower().Contains("ico"))
{
resizedImg.Save(newFilename, ImageFormat.Icon);
}
else if (fileNameExtension != null && fileNameExtension.ToLower().Contains("tiff"))
{
resizedImg.Save(newFilename, ImageFormat.Tiff);
}
else if (fileNameExtension != null && fileNameExtension.ToLower().Contains("emf"))
{
resizedImg.Save(newFilename, ImageFormat.Emf);
}
else if (fileNameExtension != null && fileNameExtension.ToLower().Contains("wmf"))
{
resizedImg.Save(newFilename, ImageFormat.Wmf);
}
else
{
success = false;
}
MessageBox.Show(success
? String.Format("Done! File saved as {0}", newFilename)
: "Something went awry. The file was not saved");
Recycle();
}
finally
{
Cursor.Current = Cursors.Default;
}
}
private void Recycle()
{
buttonResizeImage.Enabled = false;
buttonApplyPercentageChange.Enabled = false;
labelImgSelected.Text = "Image selected: ";
textBoxOrigHeight.Text = String.Empty;
textBoxOrigWidth.Text = String.Empty;
// Retain the percentage vals, as it may be that all in a batch need to be the same pair of vals
}
private void buttonApplyPercentageChange_Click(object sender, EventArgs e)
{
int origHeight = _imgToResize.Height;
int origWidth = _imgToResize.Width;
// Two ways to convert the val
double heightFactor = (double)numericUpDownHeight.Value / 100.0;
double widthFactor = Convert.ToDouble(numericUpDownWidth.Value) / 100.0;
if (heightFactor < 0 || widthFactor < 0)
{
// show an error - no negative values allowed- using updown, so that should not be possible
}
var newHeight = Convert.ToInt32(origHeight * heightFactor);
var newWidth = Convert.ToInt32(origWidth * widthFactor);
textBoxNewHeight.Text = newHeight.ToString();
textBoxNewWidth.Text = newWidth.ToString();
buttonResizeImage.Enabled = true;
}
private void textBoxNewHeight_TextChanged(object sender, EventArgs e)
{
EnableResizeButtonIfValidDimensionsEntered();
}
private void EnableResizeButtonIfValidDimensionsEntered()
{
if (String.IsNullOrWhiteSpace(textBoxOrigHeight.Text)) return;
String candidateHeight = textBoxNewHeight.Text;
String candidateWidth = textBoxNewWidth.Text;
int validHeight;
int validWidth;
buttonResizeImage.Enabled = (int.TryParse(candidateHeight, out validHeight)) &&
(int.TryParse(candidateWidth, out validWidth));
}
private void numericUpDownHeight_ValueChanged(object sender, EventArgs e)
{
if (checkBoxRetainRatio.Checked)
{
numericUpDownWidth.Value = numericUpDownHeight.Value;
}
}
private void numericUpDownWidth_ValueChanged(object sender, EventArgs e)
{
if (checkBoxRetainRatio.Checked)
{
numericUpDownHeight.Value = numericUpDownWidth.Value;
}
}
}
}