doc: update document.

.gitignore

@@ -0,0 +1,8 @@
+.DS_Store
+/.build
+/Packages
+xcuserdata/
+DerivedData/
+.swiftpm/configuration/registries.json
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc

README.md

@@ -3,6 +3,8 @@ SearchField
 
 The search input box component can be placed in a non-specific location and is consistent with the default search input box style.
 
+![SearchField](https://github.com/jaywcjlove/swiftui-searchfield/assets/1680273/43a01ac1-d5bc-42a8-a13b-716aa9eaaf20)
+
 ## Installation
 
 You can add MarkdownUI to an Xcode project by adding it as a package dependency.
@@ -29,8 +31,9 @@ struct ContentView: View {
     var body: some View {
         SearchField(searchText, textFieldChanged: { value in
             print("value\(value)")
+            searchText = value
         })
-        .padding()
+        Text(searchText)
     }
 }
 ```

SearchField/Sources/SearchField/SearchField.swift

@@ -5,35 +5,47 @@ import SwiftUI
 
 @available(macOS 10.15, *)
 public struct SearchField: View {
-    @State private var text: String = ""
+    // A binding to a string value
+    @Binding private var text: String?
+    // A closure that takes a string as input and returns void
     var textFieldChanged: ((String) -> Void)
-    var value: String
+
+    // Initializes a SearchField with a default value and a closure to be called when the text field changes
     public init(_ defaultValue: String?, textFieldChanged: @escaping ((String) -> Void)) {
-        self.value = defaultValue ?? ""
+        _text = .constant(defaultValue ?? "")
+        self.textFieldChanged = textFieldChanged
+    }
+    // Initializes a SearchField with a binding to a string value and a closure to be called when the text field changes
+    public init(_ defaultValue: Binding<String?>, textFieldChanged: @escaping ((String) -> Void)) {
+        _text = defaultValue
         self.textFieldChanged = textFieldChanged
     }
+    // Defines the body of the SearchField view
     public var body: some View {
         let binding = Binding<String>(
-            get: { self.text },
+            get: { self.text ?? "" }, // Retrieves the value of the binding
             set: {
+                // Sets the value of the binding to the new value
                 self.text = $0;
+                // Calls the closure with the new value
                 self.textFieldChanged($0)
             }
         )
-        return SearchFieldView(search: binding).onAppear {
-            text = value
-        }
+        // Returns a SearchFieldView with the created binding
+        return SearchFieldView(search: binding)
     }
 }
 
 @available(macOS 10.15, *)
 private struct SearchFieldView: NSViewRepresentable {
+    // A binding to a string value
     @Binding var search: String
     class Coordinator: NSObject, NSSearchFieldDelegate {
         var parent: SearchFieldView
         init(_ parent: SearchFieldView) {
             self.parent = parent
         }
+        // Called when the text in the search field changes
         func controlTextDidChange(_ notification: Notification) {
 //            let searchField = notification.object as! NSSearchField
 //            self.parent.search = searchField.stringValue
@@ -42,23 +54,28 @@ private struct SearchFieldView: NSViewRepresentable {
                 print("Unexpected control in update notification")
                 return
             }
+            // Sets the binding value to the new search field value
             self.parent.search = searchField.stringValue
         }
-
     }
-
+    // Creates a new NSView instance
     func makeNSView(context: NSViewRepresentableContext<SearchFieldView>) -> NSSearchField {
+        // Creates a new NSSearchField
         let tf = NSSearchField(frame: .zero)
 //        tf.focusRingType = .none
         tf.drawFocusRingMask()
         return tf
     }
 
     func updateNSView(_ searchField: NSSearchField, context: NSViewRepresentableContext<SearchFieldView>) {
+        // Updates the search field's value with the binding value
         searchField.stringValue = search
+        // Sets the coordinator as the search field's delegate
         searchField.delegate = context.coordinator
     }
 
+    // 创建一个协调器实例以与 NSView 协调
+    // Creates a coordinator instance to coordinate with the NSView
     func makeCoordinator() -> Coordinator {
         return Coordinator(self)
     }

SearchFieldExample/SearchFieldExample/ContentView.swift

@@ -10,6 +10,7 @@ import SearchField
 
 struct ContentView: View {
     @State private var searchText = ""
+
     var body: some View {
         VStack {
             Image(systemName: "globe")
@@ -18,7 +19,9 @@ struct ContentView: View {
             Text("Hello, Search Field!")
             SearchField(searchText, textFieldChanged: { value in
                 print("value\(value)")
+                searchText = value
             })
+            Text(searchText)
         }
         .padding()
     }