我正在創建一個需要使用下拉選單選擇產品狀態的表單。我為此創建了一個選擇器。資料是從我的 ViewModel 中的串列加載的，但不會被發回。我已經嘗試使用輸入欄位進行相同的操作，并且效果很好。我只是不知道如何將選擇器與視圖模型鏈接起來。
這是我的代碼。
Xaml
</Grid>
<Label Text="Current status" Style="{StaticResource MainLabel}"/>
<Label Style="{StaticResource MainLabel}" Text="{Binding ProductionStatus, Mode=TwoWay}"/>
<!-- gets send when saved-->
<Entry Style="{StaticResource MainEntry}" Text="{Binding ProductionStatus, Mode=TwoWay}" Keyboard="Text" />
<Label Text="Remark" Style="{StaticResource MainLabel} "/>
<!-- gets send when saved-->
<Entry Text="{Binding Remark}" Keyboard="Text" Style="{StaticResource MainEntry}"/>
<!-- Does not bind with anything.-->
<Picker x:Name="statusPicker" ItemsSource="{Binding ProductionOrderStatusName}" ItemDisplayBinding="{Binding Name}" SelectedItem="{Binding ProductionStatusName}"/>
<Button Style="{StaticResource PrimaryButton}" Text="Save" Command="{Binding SaveCommand}"></Button>
代碼隱藏視圖模型
public ICommand SaveCommand
{
get
{
return new Command(ExecuteSaveCommand);
}
}
private async void ExecuteSaveCommand()
{
int statusId = FindProductionOrderStatusId(ProductionStatus); //the production status should be the result of the selected value in the picker
Guid id = _CurrentProductionOrder.Id;
string remark = Remark; // value from the remark entery in the xaml
await __productionOrderService.UpdateAsync(id, remark,statusId);
}
特性
public ObservableCollection<ProductionOrderStatus> productionOrderStatusName;
public ObservableCollection<ProductionOrderStatus> ProductionOrderStatusName
{
get { return productionOrderStatusName; }
set
{
productionOrderStatusName = value;
}
}
public int amount;
public int Amount
{
get { return amount; }
set
{
amount = value;
}
}
public DateTime finishDate;
public DateTime FinishDate
{
get { return finishDate; }
set
{
finishDate = value;
}
}
public int ordernumber;
public int OrderNumber
{
get { return ordernumber; }
set
{
ordernumber = value;
}
}
public string remark;
public string Remark
{
get { return remark; }
set
{
remark = value;
}
}
public string productionStatus;
public string ProductionStatus
{
get
{
return productionStatus;
}
set
{
productionStatus = value;
}
}
private string materialNumber;
public string MaterialNumber
{
get { return materialNumber; }
set
{
materialNumber = value;
}
}
private string materialDescription;
public string MaterialDescription
{
get { return materialDescription; }
set
{
materialDescription = value;
}
}
加載我的資料背后的代碼
public OrderViewModel()
{
_productionOrderStepService = new MockingProductionOrderStepService();
_materialService = new MockingMaterialService();
__productionOrderService = new MockingProductionOrderService();
__productionOrderStatusService = new MockingProductionOrderStatusService();
_seederService = new Seeder(__productionOrderService, _productionOrderStepService, __productionOrderStatusService, _materialService);
_seederService.EnsureSeeded();
}
public override void Init(object initData)
{
_CurrentProductionOrder = initData as ProductionOrder;
LoadItemState();
base.Init(initData);
}
private void LoadItemState()
{
ObservableCollection<ProductionOrderStatus> ProductionStatusName = new ObservableCollection<ProductionOrderStatus>(__productionOrderStatusService.GetListAllAsync().Result);
this.ProductionOrderStatusName = ProductionStatusName;
this.materialDescription = FindMaterialDescription(_CurrentProductionOrder.MaterialId);
this.materialNumber = FindMaterialNumber(_CurrentProductionOrder.MaterialId);
this.productionStatus = FindProductionOrderStatus(_CurrentProductionOrder.StatusId);
this.remark = _CurrentProductionOrder.Remark;
this.amount=_CurrentProductionOrder.Amount;
this.finishDate = _CurrentProductionOrder.FinishDate;
this.ordernumber = _CurrentProductionOrder.OrderNumber;
}
謝謝你的幫助！
uj5u.com熱心網友回復：
你讓這比它需要的更復雜
<Picker x:Name="statusPicker"
// this is the List of items X to display
ItemsSource="{Binding ProductionOrderStatusName}"
// this tells the picker which property of X to display to the user
ItemDisplayBinding="{Binding Name}"
// this is the specific X the user has selected
SelectedItem="{Binding SelectedStatus}" />
然后在你的虛擬機中
public ObservableCollection<ProductionOrderStatus> ProductionOrderStatusName { get; set; }
public ProductionOrderStatus SelectedStatus { get; set; }
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標籤：xamarin xamarin.forms 虚拟机 视图模型 新鲜的MVVM