从Android的微调选择的项目，使用它 [英] Selecting Item from Android Spinner and Using It

问题描述

我是从枚举填充一个微调：

I have a spinner which is populated from an Enum:

public enum Frequencies
    {
    EVERYDAY("Every day"), EVERYOTHERDAY("Every second day");

    private String friendlyName;

    private Frequencies(String friendlyName)
    {
        this.friendlyName = friendlyName;
    }

    @Override public String toString()
    {
        return friendlyName;
    }
    };

的的toString（）覆盖意味着微调显示用户友好的名称。

The toString() overrides means the spinner displays user friendly names.

微调器填充像这样：

        ArrayAdapter<Frequencies> adapter = new ArrayAdapter<Frequencies>(this, android.R.layout.simple_spinner_item, 
            Frequencies.values());
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    newAlarmFreqSpinner.setAdapter(adapter);

这一切运作良好。当用户从选择微调的频率，我想使用的值设置长价值重新present报警之间的间隔在一个简单的报警对象。因此，对于每一天的价值会在一天的秒数。

All of this is working well. When the user chooses a frequency from the spinner, I'd like to use the value to set a long value to represent the interval between alarms in a simple Alarm object. So the value for "Every day" would be the number of seconds in one day.

不过，我不能完全得到我围绕着如何很好地处理频率对象我从微调检索头。我最初的想法是使用开关语句上显示的字符串开关，确定long值我需要的，但你当然不能够开关的字符串。

However, I can't quite get my head around how to elegantly handle the Frequency object I retrieve from the spinner. My initial thought was to use a switch statement to switch on the displayed string to determine the long value I require, but of course you can't switch on a string.

然后我试图修改频率枚举所以每个条目存储在其自己的long值：

I then tried modifying the Frequencies enum so each entry stored its own long value:

    EVERYDAY("Every day", 86400), EVERYOTHERDAY("Every second day", 86400 * 2);

private String friendlyName;
public final int intervalInSecs;

private Frequencies(String friendlyName, int intervalInSecs)
{
    this.friendlyName = friendlyName;
    this.intervalInSecs = intervalInSecs;
}...

但随后的开关抱怨说，案件前pressions必须恒定前pressions（尽管我做了 intervalInSecs最后）

    Object obj = newAlarmFreqSpinner.getSelectedItem();
    switch(((Frequencies)obj).getIntervalInSecs())
{
    case Frequencies.EVERYDAY.intervalInSecs: //Java doesn't like this
    {

        break;
    }...

我敢肯定，我在做这个难度比它确实是！我倒是AP preciate任何想法。

I'm sure I'm making this more difficult than it really is! I'd appreciate any ideas.

推荐答案

嗯，基本上枚举类型都有它的关联间隔。所以，你不需要在区间切换，只是在枚举类型切换：

Well basically the enum type has it's associated interval. So you don't need to switch on the interval, just switch on the enum type:

Object obj = newAlarmFreqSpinner.getSelectedItem();
switch((Frequencies)obj) {
case Frequencies.EVERYDAY {
    alarm.setInterval(EVERYDAY.getIntervalInSecs());
    break;
}...

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