Text

创建源

To define a Text object, use standard HTML语法 with the addition of JavaScript event handlers.

事件句柄

• onBlur
• onChange
• onFocus
• onSelect

A Text object is a form element and must be defined within a FORM tag.

Text objects can be updated (redrawn) dynamically by setting the value property (this.value).

属性概览

方法概览

示例

<B>Last name:</B> <INPUT TYPE="text" NAME="last_name" VALUE="" SIZE=25> 示例 2. The following example creates two Text objects on a form. Each object has a default value. The city object has an onFocus event handler that selects all the text in the field when the user tabs to that field. The state object has an onChange event handler that forces the value to uppercase.

<FORM NAME="form1">
<BR><B>City: </B><INPUT TYPE="text" NAME="city" VALUE="Anchorage"
   SIZE="20" onFocus="this.select()">
<B>State: </B><INPUT TYPE="text" NAME="state" VALUE="AK" SIZE="2"
   onChange="this.value=this.value.toUpperCase()">
</FORM> See also the示例 for the onBlur, onChange, onFocus, and onSelect.

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属性

安全性

描述

You can set the defaultValue property at any time. The display of the related object does not update when you set the defaultValue property, only when you set the value property.

示例

function defaultGetter() {
   msgWindow=window.open("")
   msgWindow.document.write("hidden.defaultValue is " +
      document.surfCity.hiddenObj.defaultValue + "<BR>")
   msgWindow.document.write("password.defaultValue is " +
      document.surfCity.passwordObj.defaultValue + "<BR>")
   msgWindow.document.write("text.defaultValue is " +
      document.surfCity.textObj.defaultValue + "<BR>")
   msgWindow.document.write("textarea.defaultValue is " +
      document.surfCity.textareaObj.defaultValue + "<BR>")
   msgWindow.document.close()
}

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form

描述

示例

<FORM NAME="myForm">
Form name:<INPUT TYPE="text" NAME="text1" VALUE="Beluga">
<P>
<INPUT NAME="button1" TYPE="button" VALUE="Show Form Name"
   onClick="this.form.text1.value=this.form.name">
</FORM> 示例 2. The following example shows a form with several elements. When the user clicks button2, the function showElements displays an alert dialog box containing the names of each element on the form myForm.

function showElements(theForm) {
   str = "Form Elements of form " + theForm.name + ": \n "
   for (i = 0; i < theForm.length; i++)
      str += theForm.elements[i].name + "\n"
   alert(str)
}
</script>
<FORM NAME="myForm">
Form name:<INPUT TYPE="text" NAME="text1" VALUE="Beluga">
<P>
<INPUT NAME="button1" TYPE="button" VALUE="Show Form Name"
   onClick="this.form.text1.value=this.form.name">
<INPUT NAME="button2" TYPE="button" VALUE="Show Form Elements"
   onClick="showElements(this.form)">
</FORM> The alert dialog box displays the following text:

JavaScript Alert:
Form Elements of form myForm:
text1
button1
button2 示例 3. The following example uses an object reference, rather than the this keyword, to refer to a form. The code returns a reference to myForm, which is a form containing myTextObject.

document.myForm.myTextObject.form

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name

安全性

描述

If multiple objects on the same form have the same NAME attribute, an array of the given name is created automatically. Each element in the array represents an individual Form object. Elements are indexed in source order starting at 0. For example, if two Text elements and a Textarea element on the same form have their NAME attribute set to "myField", an array with the elements myField[0], myField[1], and myField[2] is created. You need to be aware of this situation in your code and know whether myField refers to a single element or to an array of elements.

示例

newWindow=window.open("http://home.netscape.com") function valueGetter() {
   var msgWindow=window.open("")
   for (var i = 0; i < newWindow.document.valueTest.elements.length; i++) {
      msgWindow.document.write(newWindow.document.valueTest.elements[i].name + "<BR>")
   }
}

type

示例

for (var i = 0; i < document.form1.elements.length; i++) {
   document.writeln("<BR>type is " + document.form1.elements[i].type)
}

value

安全性

描述

You can set the value property at any time. The display of the Text object updates immediately when you set the value property.

示例

function valueGetter() {
   var msgWindow=window.open("")
   msgWindow.document.write("submitButton.value is " +
      document.valueTest.submitButton.value + "<BR>")
   msgWindow.document.write("resetButton.value is " +
      document.valueTest.resetButton.value + "<BR>")
   msgWindow.document.write("myText.value is " +
      document.valueTest.myText.value + "<BR>")
   msgWindow.document.close()
} This example displays the following:

submitButton.value is Query Submit
resetButton.value is Reset
myText.value is Stonefish are dangerous. The previous example assumes the buttons have been defined as follows:

<INPUT TYPE="submit" NAME="submitButton">
<INPUT TYPE="reset" NAME="resetButton">
<INPUT TYPE="text" NAME="myText" VALUE="Stonefish are dangerous.">

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方法

语法

示例

userText.blur() This example assumes that the text element is defined as

<INPUT TYPE="text" NAME="userText">

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focus

语法

描述

示例

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handleEvent

语法

select

语法

描述

示例

<FORM NAME="myForm">
<B>Last name: </B><INPUT TYPE="text" NAME="lastName" SIZE=20 VALUE="Pigman">
<BR><B>First name: </B><INPUT TYPE="text" NAME="firstName" SIZE=20 VALUE="Victoria">
<BR><BR>
<INPUT TYPE="button" VALUE="Change last name"
   onClick="this.form.lastName.select();this.form.lastName.focus();">
</FORM>

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