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我对android开发很陌生，我似乎有一个我无法理解的问题。我有一个微调器，值设置得很好，但我的提示没有出现。我试图在 xml 和 java 代码中设置它，但两者都不起作用。下面是我的配置。我觉得我缺少一些基本的东西，但我还不知道它是什么。

任何帮助，将不胜感激。克雷格

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#000000" >

    <Spinner
        android:id="@+id/band"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_marginTop="72dp"
        android:prompt="@string/year_prompt"
        android:textColor="#F0F0F0" />

    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="28dp"
        android:entries="@array/year_array"
        android:prompt="@string/year_prompt"
        android:textColor="#F0F0F0" />

</RelativeLayout>




<string name="year_prompt">Select A Year</string>
<string-array name="year_array">
    <item >2000</item>
    <item >2001</item>
    <item >2002</item>
    <item >2003</item>
    <item >2004</item>
    <item >2005</item>
</string-array>
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1 回答 1

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The reason that your promoted is not showing is because in android 3.0+, there is no space for the prompt.

This is a screen shot of a spinner pre 3.0

The prompt is at the top, where is says "Chose a Country", screen shot from http://www.mkyong.com/android/android-spinner-drop-down-list-example/

enter image description here

So the prompt is no longer shown.

There are a few possibilities.

First, you could just add an item at the top of your list-array, that says the same thing as your prompt

Otherwise you could use a button and create a drop down list from that.

First, in your layout replace your spinner with a button, and give it the text that you gave your prompt

Then move your list of items on yoour spinner to a file called optionmenu.xml

Then declare your button and set up an onClickListener for it.

Inside that method, put the following code

On the foutrh line, the layout that you specify is your optionmenu layout

public void showPopup(View v) {
PopupMenu popup = new PopupMenu(this, v);
MenuInflater inflater = popup.getMenuInflater();
inflater.inflate(R.layout.optionmenu, popup.getMenu());
popup.show();

} When you call this method, you need to do the following

    View p = (View)findViewById(R.id.spinner button);
showPopup(p);

In this price of code, View p is the view at the location that you want to show the top corner of the menu. So in this case, it will be your button

See the answer here to implement it - android menu code not working

And in each case:..... statement, put a line that sets your button text as a string.

case R.id.item1:

button.setText("item1");>

There are some other good solutions here -

How to make an Android Spinner with initial text "Select One"

于 2012-11-11T09:37:18.747 回答