C# JsonObject.asString方法代码示例

		public Section Build(JsonObject section, JsonValue data)
		{
			var sec = new Section(section.asString("caption"), section.asString("footer"));
			
			if (!string.IsNullOrEmpty(section.asString("captionImage"))) {
				var imgDevice = section.asString("captionImage").Split(' ');
				var img = UIDevice.CurrentDevice.UserInterfaceIdiom==UIUserInterfaceIdiom.Phone ? imgDevice[0] : imgDevice[1];
				sec.HeaderView = new UIImageView(UIImage.FromBundle(img));
			}
			
			if (section.ContainsKey("elements")){
					foreach (JsonObject elem in section["elements"]) {
						
						var dataForElement = data;
						var bindExpression = elem.asString("bind");
						if (bindExpression!=null) {
							try {
								if (data!=null && data.JsonType==JsonType.Object){
									var bind = elem.asString("bind");
									if (data != null && !string.IsNullOrEmpty(bind) && data.ContainsKey(bind)) {
										dataForElement = data[bind];
									}
								} else if (bindExpression.StartsWith("#")) {
									dataForElement = _controller.GetValue(bindExpression.Replace("#", "")); 
								}
							} catch (Exception e){
								Console.WriteLine("Exception when binding element " + elem.ToString()+ " - " + e.ToString());	
							}
						}
						
						_parseElement(elem, sec, dataForElement);
					}
					
				} else if (section.ContainsKey("iterate") && data != null){
					string iterationname = section["iterate"];
					JsonArray iterationdata = null;	
					if (iterationname.Contains("#")){ // for when list is in member of object
						var splittedName = iterationname.Split('#');
						var obj = (JsonObject)data[splittedName[0]];
					    iterationdata = (JsonArray)obj[splittedName[1]];           
					} else {
						iterationdata = string.IsNullOrEmpty(iterationname) ? (JsonArray)data : (JsonArray)data[iterationname];
					
					}
					string emptyMessage = section.ContainsKey("empty") ? section["empty"].CleanString() : "Empty";
					
					var template = (JsonObject)section["template"];
					
					var items = iterationdata.ToList();
					if (items.Count>0) {
						foreach(JsonValue v in items){
							_parseElement(template, sec, v);
						}
					} else {
						sec.Add(new EmptyListElement(emptyMessage));
						
					}
					
				} else if (section.ContainsKey("iterateproperties") && data != null){
					string iterationname = section["iterateproperties"];	
					string emptyMessage = section.ContainsKey("empty") ? section["empty"].CleanString() : "Empty";
					
					var iterationdata = string.IsNullOrEmpty(iterationname) ? (JsonObject)data 
						: data.ContainsKey(iterationname) ? (JsonObject)data[iterationname] : null;
					var template = (JsonObject)section["template"];
					var items =  iterationdata == null ? new List<string>() : iterationdata.Keys;
					if (items.Count>0) {
						foreach(string v in items){
							var obj = new JsonObject();
							obj.Add(v, iterationdata[v]);
							_parseElement(template, sec, obj);
						}
					} else {
						sec.Add(new EmptyListElement(emptyMessage));
						
					}
				}
			
			
			return sec;
		}

		private UIBarButtonItem _createButtonItemFor(string property, JsonValue json, JsonObject valuesJson){
			var item = (JsonObject)json[property];
			string datavalue = null, id = null;
			id = item.asString(Constants.Id);
			Activity action = null;
			UIBarButtonItem button;
			if (valuesJson!=null && !string.IsNullOrEmpty(id)){
				datavalue = valuesJson.asString(id);
			}
				
			if (item.ContainsKey(Constants.Action)) {
				action = new ControllerAction(datavalue ?? item.asString(Constants.Action));
			} else if (item.ContainsKey(Constants.Activity)) {
				action = ActivityFactory.Create(item.asString(Constants.Activity));
			}
			
			if (action==null)
				return null;
			
			if (item.ContainsKey(Constants.Image)){
				button = new UIBarButtonItem(UIImage.FromBundle(item.asString(Constants.Image)), UIBarButtonItemStyle.Plain, (object o, EventArgs a)=>{
					action.Execute(this, null, null);
				});
			} else {
				button = new UIBarButtonItem(item.asString(Constants.Caption), UIBarButtonItemStyle.Plain, (object o, EventArgs a)=>{
					action.Execute(this, null, null);
				});
			}	
			return button;
		}

		private void _parseElement(JsonObject json, Section section, JsonValue data){
			string type = "Unknown";
			try {
				type = json["type"];
				if (type=="HiddenElement"){
					var name = json.asString("id");
					_controller.SetValue(name, data==null? json.asString("value") : data.CleanString());	
				} else {
					string id = (json.ContainsKey("id") ? json["id"] : null);
					var newElement = ElementParsers.Parsers[type](json, _controller, data);
					if (newElement!=null) {
						if (!string.IsNullOrEmpty(id))
							newElement.ID = new NSString(id);
						
						section.Add(newElement);
					}
				}
			} catch (Exception e){
				Console.WriteLine("Problem parsing element. Element was skipped. Type: "+type+" = " + e.ToString());
			}
		}