如何设置 ListPreference 的默认值 [英] How to set the Default Value of a ListPreference

问题描述

我需要在 Activity 启动时为 ListPreference 设置默认值.我已经尝试过 ListPreference.setDefaultvalue("value"); 但它使列表的第一个条目成为默认值.我需要它，因为我必须检查一个条件并将满足该条件的值设置为默认值，所以我认为它不能从 xml 文件中完成(使用 android:defaultValue)

i need to set the defult value for a ListPreference when the Activity starts. I've tried with ListPreference.setDefaultvalue("value"); but it makes the firts Entry of the List as default. I need it because i must check a condition and set as default the value which satisfies that condition, so I think it can't be done from the xml file (with android:defaultValue)

例如，假设我在 arrays.xml 中有这个值数组:

For example, suppose I have this array of values in the arrays.xml:

<string-array name="opts">
    <item>red</item>
    <item>green</item>
    <item>blue</item>
</string-array>

<string-array name="opts_values">
    <item>1</item>
    <item>2</item>
    <item>3</item>
</string-array>

在 PreferenceScreen xml 中:

In the PreferenceScreen xml:

<ListPreference
    android:title="Colour select"
    android:summary="Select your favourite"
    android:key="colour"
    android:entries="@array/opts"
    android:entryValues="@array/opts_values" />

在活动中我想做这样的事情:

In the Activity I'd like to do something like this:

String mycolour;
if (something) {
    mycolour="1";
} else {
    mycolour="2";
}
ListPreference colour = (ListPreference) findPreference ("colour");
colour.setDefaultValue(mycolour);

但它不起作用，因为它使第一选择成为默认值.你能解释一下如何将另一个设为默认吗?谢谢.

But it doesn't work, because it makes the first choice as default. Could you explain me how to make another one as default? Thanks.

推荐答案

您是否尝试过:

setValueIndex(int index);

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