我們如何將文本框的值設置爲dropdownlist？

Question

function SetUtcTimeZone() { 
    var UTCTimeZone = document.getElementById("txtPortorAnchorDeparture").value; 
    document.getElementById('ddlUTCTimeZone').selectedIndex = UTCTimeZone; 
} 

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我們如何設置文本框的值使用下拉列表ID

Answer 1

我想這應該是這樣的，以DROPDOWNLIST：

function SetTxt() { 
    var indx = document.getElementById('ddlUTCTimeZone').selectedIndex; 
    var val = document.getElementById('ddlUTCTimeZone').options[indx].text; 
    document.getElementById("txtPortorAnchorDeparture").value = val; 
} 

Answer 2

下面是一個簡單的函數

function dropdownToTextbox(dropdown, textbox) { 
    var selectedOption = dropdown.options[dropdown.selectedIndex]; 
    textbox.value = selectedOption.value; 
} 

Answer 3

只需將.selectedIndex替換成.value即可做
試試這個

function SetUtcTimeZone() { 
 
    var UTCTimeZone = document.getElementById("txtPortorAnchorDeparture").value; 
 
    document.getElementById('ddlUTCTimeZone').value = UTCTimeZone; 
 
}

<!-- Simple example --> 
 
<select id="ddlUTCTimeZone"> 
 
    <option value="1">USA</option> 
 
    <option value="2">Egypt</option> 
 
    <option value="0">GMT</option> 
 
</select> 
 
<input id="txtPortorAnchorDeparture" type="text" /> 
 
<button type="button" onclick="SetUtcTimeZone()">Go</button>