C#如何将变量传递给另一种形式

Question

I am trying to add a search button so when i click the button it opens up another box which allows me to type what i want to search then press search. But i cant seem to access my arraylist and my DataStructure from form1 in form2. so was wondering how i can pass these variables so i can access them in my form2 `

    #region Variables
    FootballClub PlayerMemberData = new FootballClub(0);
    ArrayList ClubData = new ArrayList();
    public int CurrentPlayerShown = 0;
    // Path to the file for loading/saving. Note the '@' sign in front of the string. Without it all '\' have to be double '\\'
    string PlayerDetails = @"C:\Users\Clare\Desktop\Football_Player.txt";
    #endregion

    #region DataStructure
    // ==============================The Data Structure=====================================
    [Serializable]
    private struct FootballClub
    {
        //the data types making up the struct
        public string Firstname;
        public string Surname;
        public int age;
        public string Address1;
        public string Address2;
        public string City;
        public string Country;
        public string Postcode;
        public int HomeNum;
        public int MobNum;
        public string Email;
        public string EmergencyName;
        public int EmergencyNum;
        public int MinutesPlayed;
        public int Goals;
        public int Penalties;
        public char CardGiven;
        public int TotalTime;
        public int TotalGoals;
        public int TotalPenalties;

        //the "constructor". Fills data structure with default vaules 
        public FootballClub(int x)
        {
            Firstname = "";
            Surname = "";
            age = 0;
            Address1 = "";
            Address2 = "";
            City = "";
            Country = "";
            Postcode = "";
            HomeNum = 0;
            MobNum = 0;
            Email = "";
            EmergencyName = "";
            EmergencyNum = 0;
            MinutesPlayed = 0;
            Goals = 0;
            Penalties = 0;
            CardGiven = ' ';
            TotalTime = 0;
            TotalGoals = 0;
            TotalPenalties = 0;
        }
    }

    // ==============================End of Data Structure=====================================
    #endregion

    #region MatchDetails
    private void NewMatch_Butt_Click(object sender, EventArgs e)
    {
        //create a new TabPage
        TabPage newTP = new TabPage();
        //add it to the TabControl
        tabControl1.TabPages.Add(newTP);
        //set the title to 'Match'plus the tab number
        int TabPageNumber = tabControl1.SelectedIndex+1; //adds 1 from the current tab
        tabControl1.TabPages[TabPageNumber].Text = "Match " + (TabPageNumber+1);
        //make it the selected tab
        tabControl1.SelectTab(TabPageNumber);
        DeleteMatch_Butt.Enabled = true;// now that we have something to delete we can enable this button
        //make the new tab page the parent of the panel that holds all the controls
        TabPanel.Parent = tabControl1.SelectedTab; //
    }

    private void DeleteMatch_Butt_Click(object sender, EventArgs e)
    {
        // Removes the selected tab:
        tabControl1.TabPages.Remove(tabControl1.SelectedTab);
        //disable button if only one tabpage left
        if (tabControl1.SelectedIndex < 1)
        {
            DeleteMatch_Butt.Enabled = false;
        }

    }

    private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
    {
        TabPanel.Parent = tabControl1.SelectedTab;
    }

    private void MinutesPlayed_Num_ValueChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.MinutesPlayed = (int)MinutesPlayed_Num.Value;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void GoalsScored_Num_ValueChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Goals = (int)GoalsScored_Num.Value;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void PenaltiesScored_Num_ValueChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Penalties = (int)PenaltiesScored_Num.Value;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void YellowCard_RadioButt_CheckedChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.CardGiven = 'Y';
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void RedCard_RadioButt_CheckedChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.CardGiven = 'R';
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }
    #endregion

    #region PlayerDetails
    private void FirstNameTextBox_TextChanged(object sender, EventArgs e)
    {
        //1. Create a new empty structure to hold member data
        FootballClub PlayerMemberData = new FootballClub(0);
        //2. Copy content of the current entry into the new empty structure
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        //3. Change only the name currently shown in the GUI in the structure
        PlayerMemberData.Firstname = FirstNameTextBox.Text;
        //4. overwrite the old data with the changed one.
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void SurnameTextBox_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Surname = SurnameTextBox.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void PlayerAge_ValueChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.age = (int)PlayerAge.Value;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void Address1_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Address1 = Address1_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void Address2_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Address2 = Address2_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void City_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.City = City_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void Country_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Country = Country_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void Postcode_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Postcode = Postcode_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void HomeNumber_Text_TextChanged(object sender, EventArgs e)
    {
        int HomeNum;
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        HomeNum = Convert.ToInt32(HomeNumber_Text.Text);
        PlayerMemberData.HomeNum = HomeNum;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void MobileNum_Text_TextChanged(object sender, EventArgs e)
    {
        int MobNum;
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        MobNum = Convert.ToInt32(MobileNum_Text.Text);
        PlayerMemberData.HomeNum = MobNum;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void Email_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Email = Email_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void EmergName_Text_TextChanged(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.EmergencyName = EmergName_Text.Text;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    private void EmergNum_Text_TextChanged(object sender, EventArgs e)
    {
        int EmergNumber;
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        EmergNumber = Convert.ToInt32(EmergNum_Text.Text);
        PlayerMemberData.EmergencyNum = EmergNumber;
        ClubData[CurrentPlayerShown] = PlayerMemberData;
    }

    #endregion

    #region ShowMember

    private void ShowCurrentMember()
    {
        FootballClub PlayerMemberData;
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];

        FirstNameTextBox.Text = PlayerMemberData.Firstname;
        SurnameTextBox.Text = PlayerMemberData.Surname;
        PlayerAge.Value = PlayerMemberData.age;
        Address1_Text.Text = PlayerMemberData.Address1;
        Address2_Text.Text = PlayerMemberData.Address2;
        City_Text.Text = PlayerMemberData.City;
        Country_Text.Text = PlayerMemberData.Country;
        Postcode_Text.Text = PlayerMemberData.Postcode;
        HomeNumber_Text.Text = " " + PlayerMemberData.HomeNum;
        MobileNum_Text.Text = " " + PlayerMemberData.MobNum;
        Email_Text.Text = PlayerMemberData.Email;
        EmergName_Text.Text = PlayerMemberData.EmergencyName;
        EmergNum_Text.Text = " " + PlayerMemberData.EmergencyNum;
        MinutesPlayed_Num.Value = PlayerMemberData.MinutesPlayed;
        GoalsScored_Num.Value = PlayerMemberData.Goals;
        PenaltiesScored_Num.Value = PlayerMemberData.Penalties;
        if (PlayerMemberData.CardGiven == 'Y') YellowCard_RadioButt.Checked = true;
        else RedCard_RadioButt.Checked = true;
        TotalTime_Text.Text = " " + PlayerMemberData.MinutesPlayed;
        TotalGoals_Text.Text = " " + PlayerMemberData.Goals;
        TotalPenalties_Text.Text = " " + PlayerMemberData.Penalties;

        Player1.Text = "Player  " + (CurrentPlayerShown + 1);
        UpdatePrevNextBtnStatus();
    }

    private void UpdatePrevNextBtnStatus()
    {
        if (CurrentPlayerShown <= 0) PrevPlayer_Butt.Enabled = false;
        else PrevPlayer_Butt.Enabled = true;

        if (CurrentPlayerShown >= (ClubData.Count - 1)) NextPlayer_Butt.Enabled = false;
        else NextPlayer_Butt.Enabled = true;
    }
    #endregion

    #region Clear

    private void Clear_Butt_Click(object sender, EventArgs e)
    {
        ClearDetails();
    }

    private void ClearDetails()
    {
        //clear the data struct 
        FootballClub PlayerMemberData = new FootballClub(0);
        PlayerMemberData = (FootballClub)ClubData[CurrentPlayerShown];
        PlayerMemberData.Firstname = "";
        PlayerMemberData.Surname = "";
        PlayerMemberData.age = 0;
        PlayerMemberData.Address1 = "";
        PlayerMemberData.Address2 = "";
        PlayerMemberData.City = "";
        PlayerMemberData.Country = "";
        PlayerMemberData.Postcode = "";
        PlayerMemberData.HomeNum = 0;
        PlayerMemberData.MobNum = 0;
        PlayerMemberData.Email = "";
        PlayerMemberData.EmergencyName = "";
        PlayerMemberData.EmergencyNum = 0;
        PlayerMemberData.MinutesPlayed = 0;
        PlayerMemberData.Goals = 0;
        PlayerMemberData.Penalties = 0;
        PlayerMemberData.CardGiven = ' ';

        ClubData[CurrentPlayerShown] = PlayerMemberData;

        ShowCurrentMember();
    }
    #endregion

    #region Save
    private void SaveDetails()
    {
        // CREATE a file for saving (technically a 'FileStream')
        FileStream fs = new FileStream(PlayerDetails, FileMode.Create);

        // Construct a BinaryFormatter and use it to serialise the data to the stream.
        // this "serialises" the ArrayList into binary (i.e. not to human readable text file)
        BinaryFormatter binFormatter = new BinaryFormatter();

        // Write the file to disk
        binFormatter.Serialize(fs, ClubData);

        // Close the file
        fs.Close();
    } // end of Save method

    private void Form1_FormClosing(object sender, FormClosingEventArgs e)
    {
        SaveDetails();
    }


    #endregion

    #region Load
    private void LoadDetails()
    {
        // OPEN file for loading
        FileStream fs = new FileStream(PlayerDetails, FileMode.Open);

        // Construct a BinaryFormatter for de-serialisation of data from the stream.
        BinaryFormatter binFormatter = new BinaryFormatter();

        // Read the file from disk
        ClubData = (ArrayList)binFormatter.Deserialize(fs);

        // Close the file
        fs.Close();

        CurrentPlayerShown = 0;
        ShowCurrentMember();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        LoadDetails();
    }
    #endregion

    private void PrevPlayer_Butt_Click(object sender, EventArgs e)
    {
        --CurrentPlayerShown;
        ShowCurrentMember();
        UpdatePrevNextBtnStatus();
    }

    private void NextPlayer_Butt_Click(object sender, EventArgs e)
    {
        ++CurrentPlayerShown;
        ShowCurrentMember();
        UpdatePrevNextBtnStatus();

        if (Regex.IsMatch(Postcode_Text.Text, @"^(GIR 0AA|[A-PR-UWYZ]([0-9]{1,2}|([A-HK-Y][0-9]|[A-HK-Y][0-9]([0-9]|[ABEHMNPRV-Y]))|[0-9][A-HJKPS-UW]) {0,1}[0-9][ABD-HJLNP-UW-Z]{2})$"))
        {
            errorProvider1.SetError(Postcode_Text, String.Empty);
        }
        else
        {
            errorProvider1.SetError(Postcode_Text, "Not a UK postcode!\nPlease Try again.");
        }

        if (Regex.IsMatch(Email_Text.Text, @"^(?<name>[\w\.]+)\@(?<domain>.+)\.(?<extension>\w{2,}$)"))
        {
            errorProvider1.SetError(Email_Text, String.Empty);
        }
        else 
        {
            errorProvider1.SetError(Email_Text, "Not a Valid Emailaddress!\n Please Try Again");
        }

        if(Regex.IsMatch(HomeNumber_Text.Text, @"(\s*\(?0\d{4}\)?(\s*|-)\d{3}(\s*|-)\d{3}\s*)|(\s*\(?0\d{3}\)?(\s*|-)\d{3}(\s*|- )\d{4}\s*)|(\s*(7|8)(\d{7}|\d{3}(\-|\s{1})\d{4})\s*)"))
        {
            errorProvider1.SetError(HomeNumber_Text, "Not a Valid UK Phone Number!\n Please Try Again.");
        }
        else
        {
            errorProvider1.SetError(HomeNumber_Text, string.Empty);
        }

        if (Regex.IsMatch(MobileNum_Text.Text, @"^[0-9]{10,11}$"))
        {
            errorProvider1.SetError(MobileNum_Text, "Not a Valid Mobile Number\n Please Try Again");
        }
        else
        {
            errorProvider1.SetError(MobileNum_Text, string.Empty);
        }

        if (Regex.IsMatch(EmergNum_Text.Text, @"^[0-9]{10,11}$"))
        {
            errorProvider1.SetError(EmergNum_Text, "Not a Valid Mobile Number\n Please Try Again");
        }
        else
        {
            errorProvider1.SetError(EmergNum_Text, string.Empty);
        }
    }

    private void NewPlayer_Butt_Click(object sender, EventArgs e)
    {
        FootballClub PlayerMemberData;

        PlayerMemberData = new FootballClub(1);
        PlayerMemberData.Firstname = "";
        PlayerMemberData.Surname = "";
        PlayerMemberData.age = 0;
        PlayerMemberData.Address1 = "";
        PlayerMemberData.Address2 = "";
        PlayerMemberData.City = "";
        PlayerMemberData.Country = "";
        PlayerMemberData.Postcode = "";
        PlayerMemberData.HomeNum = 0;
        PlayerMemberData.MobNum = 0;
        PlayerMemberData.Email = "";
        PlayerMemberData.EmergencyName = "";
        PlayerMemberData.EmergencyNum = 0;
        PlayerMemberData.MinutesPlayed = 0;
        PlayerMemberData.Goals = 0;
        PlayerMemberData.Penalties = 0;
        PlayerMemberData.CardGiven = ' ';

        ClubData.Add(PlayerMemberData);
        ClubData.Sort(new MonarchNameComparer());
        ShowCurrentMember();



    }

    public class MonarchNameComparer : IComparer
    {
        public int Compare(object x, object y)
        {
            return ((FootballClub)x).Firstname.CompareTo(((FootballClub)y).Firstname);
        }
    }

    private void DeletePlayer_Butt_Click(object sender, EventArgs e)
    {
        ClubData.RemoveAt(CurrentPlayerShown);
        ShowCurrentMember();
    }

    private void Searching_Butt_Click(object sender, EventArgs e)
    {
        Search_Form Search = new Search_Form(); //"this" is passing the main form to the second form to be able to control the main form...
        Search.Show();

    }

}

}

    private void SearchButt_Click(object sender, EventArgs e)
    {
        string toFind;
        string source;

        toFind = Search_Text.Text;
        toFind = toFind.ToLower(); // Convert toFind string to lowercase 

        for (int i = 0; i < ClubData.Count; ++i)
        {   // Assemble the source string through which we then can search 
            source = (()ClubData[i]).FirstName + ((FootballData)ClubData[i]).age;
            source = source.ToLower(); // Convert source string to lowercase 

            if (source.Contains(toFind))
            {
                currentMemberShown = i;
                ShowCurrentMember();
                break; // break out of the 'for' loop 
            }

            if (i == (ClubData.Count - 1))
            {
                MessageBox.Show(toFind + " not found");
            }
        } // end of 'for' loop

        this.Close();
    } // end of SearchBtn even handler

}

} `

Answer 1

There are various ways to do this. One way would be to create a new constructor for the Search_Form that takes in your ClubData .

// Search_Form.cs
FootballClub ClubData;

public Search_Form(FootballClub cdata)
{
    ClubData = cdata;
}

You can then instantiate that

Search_Form Search = new Search_Form(ClubData); 
Search.Show();

Also, you should try and avoid using ArrayLists and opt for a generic collection, such as List<T> .

Answer 2

Another way would be making public the variables/whatever you wanna acces and then like that:

Let´s say in Form 1 we have this variable:

string greeting = "Hello, how are you?"

And then you want to access in Form 2:

Form1 f = new Form1();
//And then you acces the variable writing an f. before then name of it. What you´re doing here is creating an instance of Form 1 in Form 2.
//Example:
string ui = f.greeting;
//Another one:
if(f.greeting != "Hello")
{
 //Whatever
}

Hope it works!!