refactor(Display): make TValue as nullable (#4651)

Author: ArgoZhang

src/BootstrapBlazor/Components/Checkbox/CheckboxList.razor.cs

@@ -188,7 +188,7 @@ private async Task<bool> OnBeforeStateChanged(CheckboxState state)
     /// </summary>
     /// <param name="value"></param>
     /// <returns></returns>
-    protected override string? FormatValueAsString(TValue value)
+    protected override string? FormatValueAsString(TValue? value)
     {
         string? ret = null;
         if (ValueType == typeof(string))

src/BootstrapBlazor/Components/DateTimePicker/DateTimePicker.razor.cs

@@ -355,7 +355,7 @@ protected override async Task OnParametersSetAsync()
     /// <summary>
     /// 格式化数值方法
     /// </summary>
-    protected override string FormatValueAsString(TValue value)
+    protected override string FormatValueAsString(TValue? value)
     {
         var ret = "";
         DateTime? d = value switch

src/BootstrapBlazor/Components/Display/DisplayBase.cs

@@ -48,13 +48,13 @@ public abstract class DisplayBase<TValue> : BootstrapModuleComponentBase
     /// Gets or sets a callback that updates the bound value.
     /// </summary>
     [Parameter]
-    public EventCallback<TValue> ValueChanged { get; set; }
+    public EventCallback<TValue?> ValueChanged { get; set; }
 
     /// <summary>
     /// Gets or sets an expression that identifies the bound value.
     /// </summary>
     [Parameter]
-    public Expression<Func<TValue>>? ValueExpression { get; set; }
+    public Expression<Func<TValue?>>? ValueExpression { get; set; }
 
     /// <summary>
     /// 获得/设置 是否显示前置标签 默认值为 null 为空时默认不显示标签
@@ -164,7 +164,7 @@ protected override void OnParametersSet()
     /// </summary>
     /// <param name="value">The value to format.</param>
     /// <returns>A string representation of the value.</returns>
-    protected virtual string? FormatValueAsString(TValue value)
+    protected virtual string? FormatValueAsString(TValue? value)
     {
         string? ret;
         if (value is SelectedItem item)

src/BootstrapBlazor/Components/Input/BootstrapInputBase.cs

@@ -52,7 +52,7 @@ public abstract class BootstrapInputBase<TValue> : ValidateBase<TValue>
     /// 获得/设置 格式化字符串
     /// </summary>
     [Parameter]
-    public Func<TValue, string>? Formatter { get; set; }
+    public Func<TValue?, string>? Formatter { get; set; }
 
     /// <summary>
     /// 获得/设置 格式化字符串 如时间类型设置 yyyy-MM-dd
@@ -182,7 +182,7 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
     /// </summary>
     /// <param name="value"></param>
     /// <returns></returns>
-    protected override string? FormatValueAsString(TValue value) => Formatter != null
+    protected override string? FormatValueAsString(TValue? value) => Formatter != null
         ? Formatter.Invoke(value)
         : (!string.IsNullOrEmpty(FormatString) && value != null
             ? Utility.Format(value, FormatString)

src/BootstrapBlazor/Components/InputNumber/BootstrapInputNumber.razor.cs

@@ -39,13 +39,13 @@ public partial class BootstrapInputNumber<TValue>
     /// 获得/设置 数值增加时回调委托
     /// </summary>
     [Parameter]
-    public Func<TValue, Task>? OnIncrement { get; set; }
+    public Func<TValue?, Task>? OnIncrement { get; set; }
 
     /// <summary>
     /// 获得/设置 数值减少时回调委托
     /// </summary>
     [Parameter]
-    public Func<TValue, Task>? OnDecrement { get; set; }
+    public Func<TValue?, Task>? OnDecrement { get; set; }
 
     /// <summary>
     /// 获得/设置 最小值
@@ -161,9 +161,9 @@ protected override void OnAfterRender(bool firstRender)
     /// </summary>
     /// <param name="value">The value to format.</param>
     /// <returns>A string representation of the value.</returns>
-    protected override string? FormatValueAsString(TValue value) => UseInputEvent ? _lastInputValueString : GetFormatString(value);
+    protected override string? FormatValueAsString(TValue? value) => UseInputEvent ? _lastInputValueString : GetFormatString(value);
 
-    private string? GetFormatString(TValue value) => Formatter != null
+    private string? GetFormatString(TValue? value) => Formatter != null
         ? Formatter.Invoke(value)
         : (!string.IsNullOrEmpty(FormatString) && value != null
             ? Utility.Format(value, FormatString)
@@ -175,7 +175,7 @@ protected override void OnAfterRender(bool firstRender)
     /// <param name="value"></param>
     /// <returns></returns>
     /// <exception cref="InvalidOperationException"></exception>
-    protected virtual string? InternalFormat(TValue value) => value switch
+    protected virtual string? InternalFormat(TValue? value) => value switch
     {
         null => null,
         int @int => BindConverter.FormatValue(@int, CultureInfo.InvariantCulture),
@@ -288,7 +288,7 @@ protected override async Task OnBlur()
         }
     }
 
-    private TValue SetMin(TValue val)
+    private TValue? SetMin(TValue? val)
     {
         if (!string.IsNullOrEmpty(Min))
         {
@@ -317,7 +317,7 @@ private TValue SetMin(TValue val)
         return val;
     }
 
-    private TValue SetMax(TValue val)
+    private TValue? SetMax(TValue? val)
     {
         if (!string.IsNullOrEmpty(Max))
         {

src/BootstrapBlazor/Components/Radio/RadioList.razor.cs

@@ -81,7 +81,7 @@ protected override void OnParametersSet()
     /// </summary>
     /// <param name="value"></param>
     /// <returns></returns>
-    protected override string? FormatValueAsString(TValue value) => value is SelectedItem v ? v.Value : value?.ToString();
+    protected override string? FormatValueAsString(TValue? value) => value is SelectedItem v ? v.Value : value?.ToString();
 
     /// <summary>
     /// <inheritdoc/>

src/BootstrapBlazor/Components/Select/MultiSelect.razor.cs

@@ -211,7 +211,7 @@ protected override void OnAfterRender(bool firstRender)
     /// </summary>
     /// <param name="value"></param>
     /// <returns></returns>
-    protected override string? FormatValueAsString(TValue value) => value == null
+    protected override string? FormatValueAsString(TValue? value) => value == null
         ? null
         : Utility.ConvertValueToString(value);
 

src/BootstrapBlazor/Components/Transfer/Transfer.razor.cs

@@ -364,7 +364,7 @@ protected override bool TryParseValueFromString(string value, out TValue result,
     /// </summary>
     /// <param name="value"></param>
     /// <returns></returns>
-    protected override string? FormatValueAsString(TValue value) => value == null
+    protected override string? FormatValueAsString(TValue? value) => value == null
         ? null
         : Utility.ConvertValueToString(value);
 

src/BootstrapBlazor/Components/Validate/ValidateBase.cs

@@ -61,7 +61,7 @@ public abstract class ValidateBase<TValue> : DisplayBase<TValue>, IValidateCompo
     /// <summary>
     /// Gets or sets the current value of the input.
     /// </summary>
-    protected TValue CurrentValue
+    protected TValue? CurrentValue
     {
         get => Value;
         set
@@ -150,7 +150,7 @@ protected string CurrentValueAsString
     /// 获得/设置 Value 改变时回调方法
     /// </summary>
     [Parameter]
-    public Func<TValue, Task>? OnValueChanged { get; set; }
+    public Func<TValue?, Task>? OnValueChanged { get; set; }
 
     /// <summary>
     /// 获得/设置 类型转化失败格式化字符串 默认为 null