Async & Await應用: 下載bundle/texture

先準備好負責下載的函式：

 /**下載圖檔 */
public DownloadTexture(url: string): Promise {
	return new Promise((resolve, reject) => {
		cc.assetManager.loadRemote(url, function (err: Error, tex: cc.Texture2D) {
			if (err) {
				console.warn("[LoadTexure]Image ("+url+") Download is not Find !! " , err);
				reject(err);
			} else {
				resolve(tex);
			}
		});
	});
}
/**下載Bundle */
public DownloadBundle(url: string): Promise {
	return new Promise((resolve, reject) => {
		cc.assetManager.loadRemote(url, function (err: Error, bundle: cc.AssetManager.Bundle) {
			if (err) {
				console.warn("[LoadBundle]Bundle ("+url+") Download is not Find !! " , err);
				reject(err);
			} else {
				resolve(bundle);
			}
		});
	});
}
/**下載Prefabs */
public DownloadPrefab(bundle: cc.AssetManager.Bundle, path: string): Promise {
	return new Promise((resolve, reject) => {
		if(!bundle){
			console.warn("[LoadBundle]Bundle is null");
			reject();
		}
		bundle.load(path, function (err: Error, prefab: cc.Prefab) {
			if (err) {
				console.warn("[LoadBundle]Prefab ("+path+") Download is not Find !! " , err);
				reject(err);
			} else {
				resolve(prefab);
			}
		});
	});
}

接下來執行的主流程如下：

public Main(){
	let bundle: cc.AssetManager.Bundle = null;
	await this.DownloadBundle(downloadPath).catch((err: any) => {
		cc.warn("Error!", "Can't Get Bundle (path:"+downloadPath+")");
	}).then((result: cc.AssetManager.Bundle) =>{
		bundle = result;
	});
	if (bundle == null) return;
	let prefab: cc.Prefab = null;
	await this.DownloadPrefab(bundle, "main").catch((err: any) => {
		cc.warn("Error!", "Can't Get Prefab (path:"+downloadPath+")");
	}).then((result: cc.Prefab) =>{
		prefab = result;
	});
	if (prefab == null) return;
	let child: cc.Node = cc.instantiate(prefab);
	child.parent = this.node;
}