Promise在await报错后,如何继续往下跑...

 一、resolve

当a>0时,正常情况依次输出A、B、C

	console.log("A");
	let result = await this.test();
	console.log("C:",result);

	private  test(){
		return new Promise((resolve,reject)=>{
			console.log("B");
			let a = 3;
			if(a > 0){
				resolve(a);
			}else{
				reject(0);
			}
		});
	}

二、没有处理失败信息,导致程序无法继续执行

当a<0时。输出A、B后,C无法输出,程序无法继续往下执行。

	console.log("A");
	let result = await this.test();
	console.log("C:",result);

	private  test(){
		return new Promise((resolve,reject)=>{
			console.log("B");
			let a = -3;
			if(a > 0){
				resolve(a);
			}else{
				reject(0);
			}
		});
	}

三、catch

增加catch处理错误,程序可以继续执行

	console.log("A");
	let result = await this.test();
	console.log("C:",result);

	private  test(){
		return new Promise((resolve,reject)=>{
			console.log("B");
			let a = -3;
			if(a > 0){
				resolve(a);
			}else{
				reject(0);
			}
		}).catch((err)=>{
			console.log("err:", err);
		});
	}

这样也可以

let result = await this.test().catch(()=>{});

  

四、使用then处理错误,程序继续执行

 换一种写法,使用then。

	console.log("A");
	let result = await this.test().then((res)=>{
		console.log("success:", res);
	},(res)=>{
		console.log("fail:", res);
	});
	console.log("C:",result);


	private  test(){
		return new Promise((resolve,reject)=>{
			console.log("B");
			let a = -3;
			if(a > 0){
				resolve(a);
			}else{
				reject(0);
			}
		});
	}

五、在await处使用catch,程序继续执行

    protected async createGameScene() {
        console.log("A");
        let result = await this.test().catch((err)=>{console.log("err:",err)});
        console.log("C:",result);
    }

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        });
    }

六、在test里catch后,程序会不执行then的reject,而是resolve。

    protected async createGameScene() {
        console.log("A");
       let result = await this.test().then((res)=>{
           console.log("C:",res);
       },(res)=>{
           console.log("D:",res)
       }).catch((err)=>{console.log("E:",err)});
    console.log("F:",result);
    }

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        }).catch((err)=>{console.log("test err:", err)});
    }

  

原文地址:https://www.cnblogs.com/gamedaybyday/p/9543368.html