docxx docxx - 13 days ago 7
C# Question

saving file to folder

Here is the code I wrote, but it does not work. I don't know how to fix it. I hope you can help me. I am out of ideas :( and you are my only hope.

namespace Imgur
{
public partial class Form1 : Form
{
bool flag = true;
int downloadedNumber = 0;

public Form1()
{
InitializeComponent();
}

public void buttonStart_Click(object sender, EventArgs e)
{
buttonStart.Enabled = false;
buttonStop.Enabled = true;
if (!flag)
{
flag = true;
}

for (int i=0;i<100000 && flag;i++)
{
WebClient webClient = new WebClient();
string pic1 = rnd_str(5);
string pic2 = ".jpg";
string picture = pic1 + pic2;

//********** GETTING SIZE OF IMAGE ***********
Size sz = GetSize("http://i.imgur.com/" + picture);
string imageSize = (sz.Width.ToString() + " " + sz.Height.ToString()); ;
//********************************************

if(imageSize != "161 81")
{
webClient.DownloadFile("http://i.imgur.com/" + picture, destination + picture);

richTextBox1.Text += String.Format("Downloaded picture: {0}\r\n", picture);
downloadedNumber++;
textBoxDownloadedNumber.Text = string.Format("{0}", downloadedNumber);
}
webClient.Dispose();
Application.DoEvents();
if (i == 999995)
{
flag = false;
}
}
richTextBox1.Text += "theend\n";
buttonStart.Enabled = true;
buttonStop.Enabled = false;
}

public static Size GetSize(string url)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
request.Accept = "image/gif";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
Bitmap bmp = new Bitmap(s);
Size sz = new Size(bmp.Width, bmp.Height);
return sz;
}

public static string rnd_str(int liczba_liter)
{
Random r = new Random();
int char_type;
string return_string = "";
int i =0;
for (i = 0; i < liczba_liter; i++)
{
if (r.Next(1, 3) == 1)
{
char_type = r.Next(1, 4);
switch (char_type)
{
case 1:
return_string += (char)r.Next(48, 58); // convertion int -> ASCII character; 48-57 are ASCII digits
break;
case 2:
return_string += (char)r.Next(97, 123); // convertion int -> ASCII character; as above but small letters
break;
case 3:
return_string += (char)r.Next(65, 91); // as above; large letters
break;
default:
i -= 1;
break;//do not add any letter if no type is allowed
}
}
else
{
i -= 1;
return_string += "";
}
}
return return_string;
}

private void buttonStop_Click(object sender, EventArgs e)
{
flag = false;
buttonStart.Enabled = true;
}

public void buttonSaveTo_Click(object sender, EventArgs e)
{
FolderBrowserDialog fbd = new FolderBrowserDialog();
fbd.ShowDialog();
richTextBox1.Text = fbd.SelectedPath;
string destination = fbd.SelectedPath;
}
}
}

Answer

It looks like you are using a variable called destination in this line

webClient.DownloadFile("http://i.imgur.com/" + picture, destination + picture);

however you have not declared that variable and assigned it a value inside the buttonStart_Click method.

You have a variable called destination declared in the buttonSaveTo_Click method, if this is the value you want to use in buttonStart_Click, you need to make it a class level field so declare it next to 'bool flag'

e.g:

public partial class Form1 : Form
{
    bool flag = true;
    int downloadedNumber = 0;
    string destination;
}

and remove the string declaration from

public void buttonSaveTo_Click(object sender, EventArgs e)
{
    FolderBrowserDialog fbd = new FolderBrowserDialog();
    fbd.ShowDialog();
    richTextBox1.Text = fbd.SelectedPath;
    destination = fbd.SelectedPath;
}