英文:
How to trigger a method with parameter through a dropdown in Blazor?
问题
I would like to trigger a method through a dropdown list in my editform. The method should be fired when I change the value in my dropdown list. But it seems not to work, anyone know what I'm doing wrong?
My code in UI.
<EditForm Model="@exampleModel">
<p>
<label>
Name:
<InputSelect @onchange="() => GetNames(name)" @bind-Value="name">
@foreach (string item in names)
{
<option value="name">@item</option>
}
</InputSelect>
</label>
</p>
<EditForm />
My code
@code {
public string? name { get; set; }
public async Task GetNames(string name)
{
// Get Names
}
string[] names = new string[] { "test", "test1", "test2", "test3", "test4" };
}
英文:
I would like to trigger a method through a dropdown list in my editform. The method should be fired when i change the value in my dropdownlist. But it seems not to work, anyone know what i doing wrong?
My code in UI.
<EditForm Model="@exampleModel">
<p>
<label>
Name:
<InputSelect @onchange="() => GetNames(name)" @bind-Value="name">
@foreach (string item in names)
{
<option value="name">@item</option>
}
</InputSelect>
</label>
</p>
<EditForm />
My code
@code {
public string? name{ get; set; }
public async Task GetNames(string name)
{
// Get Names
}
string[] names = new string[] { "test", "test1", "test2", "test3", "test4" };
}
答案1
得分: 2
以下是您提供的代码的中文翻译部分：
尝试：
<EditForm Model="@exampleModel" >
<p>
<label>
名称：
<Select @onchange="GetNames" >
@foreach (var item in names)
{
<option value="@item">@item</option>
}
</Select>
</label>
</p>
</EditForm>
@code {
private ExampleModel exampleModel = new();
public string? name { get; set; }
public async Task GetNames(ChangeEventArgs e)
{
// 获取名称
name = e.Value.ToString();
}
string[] names = new string[] { "test", "test1", "test2", "test3", "test4" };
}
希望这对您有所帮助。如果您需要进一步的翻译或其他帮助，请随时提问。
英文:
Try:
<EditForm Model="@exampleModel" >
<p>
<label>
Name:
<Select @onchange="GetNames" >
@foreach (var item in names)
{
<option value="@item">@item</option>
}
</Select>
</label>
</p>
</EditForm>
@code {
private ExampleModel exampleModel = new();
public string? name { get; set; }
public async Task GetNames(ChangeEventArgs e)
{
// Get Names
name = e.Value.ToString();
}
string[] names = new string[] { "test", "test1", "test2", "test3", "test4" };
}
result:
答案2
得分: 1
这演示了两种不同的方法，取决于你使用的DotNet版本：
@page "/"
<PageTitle>Index</PageTitle>
<EditForm Model=_model>
<h3>Net7.0+</h3>
<div class="mb-3">
<label class="form-label"> 姓名:</label>
<InputSelect class="form-select" @bind-Value="@_name" @bind-Value:after=GetNames>
@if (_name is null)
{
<option selected disabled value="">-- 选择一个姓名 --</option>
}
@foreach (string item in names)
{
<option value="@item">@item</option>
}
</InputSelect>
</div>
<h3>Net6.0+</h3>
<div class="mb-3">
<label class="form-label"> 姓名:</label>
<InputSelect class="form-select" TValue=string Value=_name ValueChanged=this.SetName ValueExpression="() => _name">
@if (_name is null)
{
<option selected disabled value="">-- 选择一个姓名 --</option>
}
@foreach (string item in names)
{
<option value="@item">@item</option>
}
</InputSelect>
</div>
</EditForm>
<div class="bg-dark text-white m-2 p-2">
<pre>结果 = @_result</pre>
</div>
@code {
private string[] names = new string[] { "test", "test1", "test2", "test3", "test4" };
private Model _model = new();
public string? _name { get; set; }
private string? _result;
public async Task GetNames()
{
await Task.Delay(500);
_result = $"在 {DateTime.Now.ToLongTimeString()} 找到 {_name}";
}
public async Task SetName(string? value)
{
_name = value;
await GetNames();
}
public class Model
{
}
}
英文:
This demonstrates doing it in two different ways depending on which version of DotNet you're using:
@page "/"
<PageTitle>Index</PageTitle>
<EditForm Model=_model>
<h3>Net7.0+</h3>
<div class="mb-3">
<label class="form-label"> Name:</label>
<InputSelect class="form-select" @bind-Value="@_name" @bind-Value:after=GetNames>
@if (_name is null)
{
<option selected disabled value="">-- Select a Name --</option>
}
@foreach (string item in names)
{
<option value="@item">@item</option>
}
</InputSelect>
</div>
<h3>Net6.0+</h3>
<div class="mb-3">
<label class="form-label"> Name:</label>
<InputSelect class="form-select" TValue=string Value=_name ValueChanged=this.SetName ValueExpression="() => _name">
@if (_name is null)
{
<option selected disabled value="">-- Select a Name --</option>
}
@foreach (string item in names)
{
<option value="@item">@item</option>
}
</InputSelect>
</div>
</EditForm>
<div class="bg-dark text-white m-2 p-2">
<pre>Result = @_result</pre>
</div>
@code {
private string[] names = new string[] { "test", "test1", "test2", "test3", "test4" };
private Model _model = new();
public string? _name { get; set; }
private string? _result;
public async Task GetNames()
{
await Task.Delay(500);
_result = $"Found {_name} at {DateTime.Now.ToLongTimeString()}";
}
public async Task SetName(string? value)
{
_name = value;
await GetNames();
}
public class Model
{
}
}
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