// #ifdef APP
			async init() {
				uni.showLoading({
				  title: '检测支付环境...'
				});
					
				try {
					// 初始化，获取iap支付通道
					await this._iap.init();
					// 从苹果服务器获取产品列表
					this.productList = await this._iap.getProduct();
					this.productList[0].checked = true;
					this.productId = this.productList[0].productid;
					console.log('this.productId',this.productId);
					console.log('this.productList',this.productList);
				} catch (e) {
					uni.showModal({
						title: "init",
						content: e.message,
						showCancel: false
					});
				} finally {
					uni.hideLoading();
				}
					
				if (this._iap.ready) {
					this.restore();
				}
			},
			async restore() {
				// 检查上次用户已支付且未关闭的订单，可能出现原因：首次绑卡，网络中断等异常
				// 在此处检查用户是否登陆
					
				uni.showLoading({
					title: '正在检测已支付且未关闭的订单...'
				});
					
				try {
					// 从苹果服务器检查未关闭的订单，可选根据 username 过滤，和调用支付时透传的值一致
					const transactions = await this._iap.restoreCompletedTransactions({
						username: this.userInfo.user_name
					});
					
					if (!transactions.length) {
						return;
					}
					
					  // 开发者业务逻辑，从服务器获取当前用户未完成的订单列表，和本地的比较
					  // 此处省略
					
				  switch (transaction.transactionState) {
						case IapTransactionState.purchased:
							// 用户已付款，在此处请求开发者服务器，在服务器端请求苹果服务器验证票据
							//let result = await this.validatePaymentResult();
			
							// 验证通过，交易结束，关闭订单
							// if (result) {
							//   await this._iap.finishTransaction(transaction);
							// }
							break;
						case IapTransactionState.failed:
							// 关闭未支付的订单
							await this._iap.finishTransaction(transaction);
							break;
						default:
							break;
				  }
				} catch (e) {
					  uni.showModal({
						content: e.message,
						showCancel: false
					  });
				} finally {
					uni.hideLoading();
				}
			},
			async payment() {
				if (this.loading == true) {
				  return;
				}
				this.loading = true;
					
				uni.showLoading({
				  title: '支付处理中...'
				});
					
				try {
					// 请求苹果支付
					const transaction = await this._iap.requestPayment({
						productid: this.productId,
						manualFinishTransaction: true,
						username: this.userInfo.user_name
					});
					console.log(transaction,'transaction');
					const res = await this.$service.getApplePaySign({
						receipt: transaction.transactionReceipt,
						id: this.detail.data[this.activeId].id,
						time: this.active
					})
					console.log(res,'借口返回');
					uni.showToast({
						icon:'none',
						title: res.msg
					})
					//支付成功
				} catch (e) {
					console.log(e,'e');
					uni.showModal({
						content: e.message,
						showCancel: false
					});
					
				} finally {
					this.loading = false;
					uni.hideLoading();
				}
			},

使用前先创建并引入以下文件：

// uni iap

const ProviderType = {
  IAP: 'iap'
}

const IapTransactionState = {
  purchasing: "0", // A transaction that is being processed by the App Store.
  purchased: "1", // A successfully processed transaction.
  failed: "2", // A failed transaction.
  restored: "3", // A transaction that restores content previously purchased by the user.
  deferred: "4" // A transaction that is in the queue, but its final status is pending external action such as Ask to Buy.
};

class Iap {

  _channel = null;
  _channelError = null;
  _productIds = [];

  _ready = false;

  constructor({
    products
  }) {
    this._productIds = products;
  }

  init() {
    return new Promise((resolve, reject) => {
      this.getChannels((channel) => {
        this._ready = true;
        resolve(channel);
      }, (err) => {
        reject(err);
      })
    })
  }

  getProduct(productIds) {
    return new Promise((resolve, reject) => {
      this._channel.requestProduct(productIds || this._productIds, (res) => {
        resolve(res);
      }, (err) => {
        reject(err);
      })
    });
  }

  requestPayment(orderInfo) {
    return new Promise((resolve, reject) => {
      uni.requestPayment({
        provider: 'appleiap',
        orderInfo: orderInfo,
        success: (res) => {
          resolve(res);
        },
        fail: (err) => {
          reject(err);
        }
      });
    });
  }

  restoreCompletedTransactions(username) {
    return new Promise((resolve, reject) => {
      this._channel.restoreCompletedTransactions({
        manualFinishTransaction: true,
        username
      }, (res) => {
        resolve(res);
      }, (err) => {
        reject(err);
      })
    });
  }

  finishTransaction(transaction) {
    return new Promise((resolve, reject) => {
      this._channel.finishTransaction(transaction, (res) => {
        resolve(res);
      }, (err) => {
        reject(err);
      });
    });
  }

  getChannels(success, fail) {
    if (this._channel !== null) {
      success(this._channel)
      return
    }

    if (this._channelError !== null) {
      fail(this._channelError)
      return
    }

    uni.getProvider({
      service: 'payment',
      success: (res) => {
        this._channel = res.providers.find((channel) => {
          return (channel.id === 'appleiap')
        })

        if (this._channel) {
          success(this._channel)
        } else {
          this._channelError = {
            errMsg: 'paymentContext:fail iap service not found'
          }
          fail(this._channelError)
        }
      }
    });
  }

  get channel() {
    return this._channel;
  }
}

export {
  Iap,
  IapTransactionState
}

效果图：

 需要注意的是，这里是沙盒环境，只能使用虚拟账号进行支付：

可以在下面这个页面进行添加账号：

Apple 内购申请流程： 苹果支付内购申请-CSDN博客

参考：uniapp开发对接IOS应用内支付

其他解决方案：

uni-pay：uni-pay - DCloud 插件市场