C# - 文本框输入范围

Question

I have a form with 4 text boxes. I'm trying to code a method that checks to make sure the inputs in the 1st and 3rd textbox are between 0 and 100. This is an example that I found. But, I'm confused on how you can check both text boxes if there is only 1 parameter for the textbox. I know that you need to convert the inputs because text boxes only accept strings. What I'm having trouble with is after converting the 2 text boxes, how do you check both of them in this if statement. Do you convert both textboxes, give them different variable names, and then use those variables in 2 different if statements? Would it be correct to just repeat this statement for the other textbox?

public bool IsWithinRange(TextBox textBox, string name, decimal min, decimal max)
        {
            number = txtOperand1.Text, txtOperand2.Text;

            if (number < 0 || number > 100)
            {
                MessageBox.Show(name + " must be between " + min + " and " + max + ".", "Entry Error");
                textBox.Focus();
                return false;
            }
            return true;
        }

Answer 1

To validate the values of TextBox you just need to parse each fileds data/text as int simply parsing & a checking method is enough.

As @Jimi pointed out, for WinForms :

private void button1_Click_1(object sender, EventArgs e)
{
    int f = 0, t = 0;

    if (Int32.TryParse(textBox1.Text, out f))
    {
        // successfully parsed 
    }

    if (Int32.TryParse(textBox3.Text, out t))
    {
        // successfully parsed 

    }

    // or just use parse..
    int f1 = Int32.Parse(textBox1.Text);
    int t1 = Int32.Parse(textBox3.Text);


    if (rangeCheck(f, t))
    {
       // Success 
    }
}
bool rangeCheck(int first, int third)
{
    return (first >= 0 && first <= 100 && third >= 0 && third <= 100);
}

Your Form Designer code: modify according to your needs

            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(230, 75);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(100, 20);
            this.textBox1.TabIndex = 0;
            // 
            // textBox2
            // 
            this.textBox2.Location = new System.Drawing.Point(230, 123);
            this.textBox2.Name = "textBox2";
            this.textBox2.Size = new System.Drawing.Size(100, 20);
            this.textBox2.TabIndex = 1;
            // 
            // textBox3
            // 
            this.textBox3.Location = new System.Drawing.Point(230, 168);
            this.textBox3.Name = "textBox3";
            this.textBox3.Size = new System.Drawing.Size(100, 20);
            this.textBox3.TabIndex = 2;
            // 
            // textBox4
            // 
            this.textBox4.Location = new System.Drawing.Point(230, 211);
            this.textBox4.Name = "textBox4";
            this.textBox4.Size = new System.Drawing.Size(100, 20);
            this.textBox4.TabIndex = 3;
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(230, 262);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 4;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click_1);

Using WPF

 <TextBox Name="box1"  ...other_properties  />
 <TextBox Name="box2"  ...other_properties  />
 <TextBox Name="box3"  ...other_properties  />
 <TextBox Name="box4"  ...other_properties  />

 <Button Click="Button_Click" Content="Check for validity" ...other properties />

Now handle those:

private void Button_Click(object sender, RoutedEventArgs e)
        {

            int f = 0, t = 0;

            if (Int32.TryParse(box1.Text, out f))
            {
               // successfully parsed 
            }

            if (Int32.TryParse(box3.Text, out t))
            {
                // successfully parsed 

            }

            // or just use parse..
            int f1 = Int32.Parse(box1.Text);
            int t1 = Int32.Parse(box3.Text);


            if (rangeCheck(f, t))
            {
                Debug.WriteLine("Both are within 0 and 100");
            }
        }

        bool rangeCheck(int first, int third)
        {
            return (first >= 0 && first <= 100 && third >= 0 && third <= 100);
        }

Answer 2

You can use the following code to make sure the inputs in the 1st and 3rd textbox are

between 0 and 100.

private void button1_Click(object sender, EventArgs e)
        {
            int m = 0;
            int n = 0;
            bool a = int.TryParse(textBox1.Text, out  m);
            bool b = int.TryParse(textBox3.Text, out n);
            if(a&b==false)
            {
                MessageBox.Show("please enter number");
            }
            else
            {
                bool t = IsWithinRange(m,"textbox1", 1, 100);
                t= IsWithinRange(n, "textbox3", 1, 100);
            }

        }
        public bool IsWithinRange(int a, string name,decimal min, decimal max)
        {
            if(a>=min&&a<=max)
            {
                MessageBox.Show(name + " is between " + min + " and " + max + ".", "Right");
            }
            else
            {
                MessageBox.Show(name + " must be between " + min + " and " + max + ".", "Entry Error");
            }
            return true;
        }