Question

我试图通过文本框将新变量设置为我的Filed（实例）值为新值...但我不知道如何制作它...这是我的代码希望我能从别人那里获得一些见解。

private string barkSound;
private string breed;
private int dogHeight;
private string dogColour;
private static int noOfLegs;

所有get和set都已设置。

public Dog()   
{
    barkSound = "Woof!";
    breed = "cocker spaniel";
    dogHeight = 10;
    dogColour = "white";   
}

public string GetSpeech()
{
    dogSpeech = "Hello. I am a " + breed + ". " + barkSound + "\n I'm " 
                    + (IsBig()? "Big" : "Small") +", i got " + DogHeight +" CM, Colour is " + dogColour + ". I have " + noOfLegs + " Legs" ;
    return dogSpeech;
}

public Dog()
{
    barkSound = "Woof!";
    breed = "cocker spaniel";
    // Question(C) add Constructor for dogHeight. dogColour and breed.
    dogHeight = 10;
    dogColour = "white";
}

Answer 1

好的，我创建了一个像你一样的表单。在创建按钮我创建了新的Dog。

这是我的Dog课程，

public class Dog
        {
            private string barkSound;
            private string breed;
            private int dogHeight;
            private string dogColour;
            public Dog(string bark, string breed, int height, string color)
            {
                this.barkSound = bark;
                this.breed = breed;
                this.dogHeight = height;
                this.dogColour = color;

            }
            public string BarkingSound { get { return this.barkSound; } }
            public string BreedName { get { return this.breed; } }
            public string Height { get { return this.dogHeight.ToString(); } }
        }

这是“创建”按钮的点击（我有Dog列表，可以添加狗狗）;

List<Dog> dogs = new List<Dog>();
private void createBtn_Click(object sender, EventArgs e)
        {
            Dog myDog = new Dog(textBox1.Text, textBox2.Text, int.Parse(textBox3.Text), textBox4.Text);
            dogs.Add(myDog);
        }

在GetDogs Button的Click我循环所有的狗并将它们添加到listbox。

 private void button1_Click(object sender, EventArgs e)
        {   listBox1.Items.Clear();
            foreach (var item in dogs)
            {
                string text = "Hello. I am a " + item.BreedName + ". " + item.BarkingSound + "etc";
                listBox1.Items.Add(text);
            }
        }

问题不明确，也许你想改变狗的现有价值。

首先，我们需要在Dog类进行更改。

public class Dog{
        private string barkSound;
        private string breed;
        private int dogHeight;
        private string dogColour;
        public Dog(string bark, string breed, int height, string color)
        {
            this.barkSound = bark;
            this.breed = breed;
            this.dogHeight = height;
            this.dogColour = color;

        }
        public string BarkingSound { get { return this.barkSound; }  set { this.barkSound = value; }  } // so we can set variables like this dog.BarkingSound = "bla"
        public string BreedName { get { return this.breed; } }
        public string Height { get { return this.dogHeight.ToString(); } }
    }

为什么我们这样做？

在listbox's selected index change event，首先我们需要使用Dog在列表中找到ElementAt()。然后检查BarkSound的文本框，如果它不为空，则将其设置为现有的狗BarkingSound，

 private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (textBox1.Text != "")
            {
                Dog TempDog = dogs.ElementAt(listBox1.SelectedIndex);
                TempDog.BarkingSound = textBox1.Text;
            }

        }

试图用两种方式解释，希望其中一个对你有用。

Answer 2

您的问题是您的字段包含private修饰符。这意味着，Dog类之外的另一个代码无法修改您的字段。我还建议使用自动生成的属性：

SomeProperty { get; set; }

因此，如果要在类外的任何地方修改字段，属性或方法，则应使用public修饰符声明它们。在你的情况下：

public string BarkSound;
public string Breed;
public int DogHeight;
public string DogColour;
public static int NoOfLegs;

创建Dog对象（Dog dog = new Dog();）后，您可以更改以下属性：

dog.BarkSound = barkSoundTextBox.Text;

用于更改实例值的文本框

2 个答案: