通过获取实体的值，在mvc中使用javascript根据选定的下拉值填充文本框

<select id="dropdown">
  <option value="value1">Option 1</option>
  <option value="value2">Option 2</option>
  <option value="value3">Option 3</option>
</select>

<input type="text" id="textbox">

var dropdown = document.getElementById("dropdown");
var textbox = document.getElementById("textbox");

dropdown.addEventListener("change", function() {
  var selectedValue = dropdown.value;
  // 在这里根据选定的值填充文本框
});

dropdown.addEventListener("change", function() {
  var selectedValue = dropdown.value;
  
  if (selectedValue === "value1") {
    textbox.value = "填充值1";
  } else if (selectedValue === "value2") {
    textbox.value = "填充值2";
  } else if (selectedValue === "value3") {
    textbox.value = "填充值3";
  }
});

var fillValues = {
  "value1": "填充值1",
  "value2": "填充值2",
  "value3": "填充值3"
};

dropdown.addEventListener("change", function() {
  var selectedValue = dropdown.value;
  textbox.value = fillValues[selectedValue];
});