Golang策略模式动态切换实现详解

<code>type PaymentStrategy interface {
    Pay(amount float64) string
}
</code>

<code>type CreditCardPayment struct{}

func (c *CreditCardPayment) Pay(amount float64) string {
    return fmt.Sprintf("Paid %.2f using Credit Card", amount)
}

type PayPalPayment struct{}

func (p *PayPalPayment) Pay(amount float64) string {
    return fmt.Sprintf("Paid %.2f via PayPal", amount)
}

type CryptoPayment struct{}

func (c *CryptoPayment) Pay(amount float64) string {
    return fmt.Sprintf("Paid %.2f in Bitcoin", amount)
}
</code>

<code>type PaymentContext struct {
    strategy PaymentStrategy
}

func (p *PaymentContext) SetStrategy(strategy PaymentStrategy) {
    p.strategy = strategy
}

func (p *PaymentContext) ExecutePayment(amount float64) string {
    if p.strategy == nil {
        return "No strategy set"
    }
    return p.strategy.Pay(amount)
}
</code>

<code>context := &PaymentContext{}

context.SetStrategy(&CreditCardPayment{})
fmt.Println(context.ExecutePayment(100.0)) // 输出：Paid 100.00 using Credit Card

context.SetStrategy(&PayPalPayment{})
fmt.Println(context.ExecutePayment(200.0)) // 输出：Paid 200.00 via PayPal
</code>