現在我有一個學校項目要在我的手機上構建一個應用程序。我們正在使用 React Native 和 Java。我想在應用程序中制作一個按鈕，按下時會變為隨機顏色。然而，這不起作用。這是我的一些代碼片段：    export default class HomeScreen extends React.Component {  constructor(props) {  super(props);  this.state = {color: "#000000"}}  render() {    let color = this.state.color;  return (...<View>          <Button          onPress = {changecolor}          title = "This button changes color when pressed"          color = {color}/>        </View>...numbers = ["0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"];this.random = this.numbers[Math.floor(Math.random() * this.numbers.length)];function changecolor() {  this.replaceState({color: String("#"+random+random+random+random+random+random)});} 在此之前我也遇到了一個問題，該按鈕只會變成灰色陰影而不是任何顏色。請問有什么幫助嗎？編輯：我應該提到我之前使用過 this.setState 并且結果相同