如何在ggplot2中将特定数字添加到图例条形图？

library(ggplot2)

# 创建数据框
data <- data.frame(
  category = c("A", "B", "C"),
  value = c(10, 20, 30)
)

# 创建条形图
plot <- ggplot(data, aes(x = category, y = value, fill = category)) +
  geom_bar(stat = "identity") +
  labs(title = "Bar Chart", x = "Category", y = "Value")

# 添加数字到图例
plot <- plot + geom_text(aes(label = value), vjust = -0.5)

# 显示图形
print(plot)