c# - Blazor 如何使用绑定(bind)到 bool 数组

Question

这个问题在这里已经有了答案:

For loop not returning expected value - C# - Blazor (1 个回答)

关闭 3年前。

我有一个对象数组，其中有一个 IsChecked 属性。我用一个数组填充表格，对于 IsChecked 属性，我会通过 @bind 来输入。

当我尝试切换值时，会出现错误。如果我立即更改值 IsChecked = true，则勾选标记。

for(var i = 0; i < firms.Length; i++)
{
    <tr>
        <td>@firms[i].ShortTitle</td>
        <th scope="row">
            <div class="custom-control custom-checkbox">
                <input type="checkbox" ... @bind="@firms[i].IsChecked" />
             ..
            </div>
        </th>
    </tr>
}

错误:

Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer: Warning: Unhandled exception rendering component: Index was outside the bounds of the array.

System.IndexOutOfRangeException: Index was outside the bounds of the array. at ....<>c__DisplayClass0_1.b__6(Boolean __value) at Microsoft.AspNetCore.Components.EventCallbackFactoryBinderExtensions.<>c__DisplayClass22_0`1.b__0(ChangeEventArgs e) --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task) at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle) Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost: Error: Unhandled exception in circuit 'LzL8iNZr7FmkJFJRS3QTW3QzJwP9R-p3CaclRHcE1_A.'.

System.IndexOutOfRangeException: Index was outside the bounds of the array. at ...<>c__DisplayClass0_1.b__6(Boolean __value) at Microsoft.AspNetCore.Components.EventCallbackFactoryBinderExtensions.<>c__DisplayClass22_0`1.b__0(ChangeEventArgs e) --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task) at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

我做错了什么？

Answer 1

在您的代码中的某处(您不会显示所有代码)“委托(delegate)”EventCallback 被执行，但“索引超出了数组的范围”；发生这种情况是因为访问索引值的代码总是获得最后一个索引 + 1

要解决此问题，请使用应为其分配 i 值的局部变量，例如“

var local = i;

See my answer here...

希望这会有所帮助...