Question

我有一个MultiSelectListPreference，显示用户关闭多选对话框时的周数列表我希望使用%s在摘要中显示所选值，但它仅适用于ListPreference。对此有什么解决方案吗？

<MultiSelectListPreference
        android:id="@+id/pref_select_week"
        android:defaultValue="@array/week_array_values"
        android:entries="@array/week_array"
        android:entryValues="@array/week_array_values"
        android:icon="@drawable/ic_pref_time"
        android:key="keyZodiacSign"
        android:summary="%s"
        android:title="Select Days" />

Answer 1

您需要创建MultiSelectListPreference的自定义版本和ovveride getSummary方法，如下所示：

@Override
public CharSequence getSummary() {
    CharSequence cs = super.getSummary();
    String summary = cs.toString();

    if (summary.contains("%s")) {
        String text = "";
        StringBuilder builder = new StringBuilder();
        CharSequence[] entries = getEntries();
        if(entries.length > 0) {
            CharSequence[] entryValues = getEntryValues();
            Set<String> values = getValues();
            int pos = 0;

            for (String value : values) {
                pos++;
                int index = -1;
                for (int i = 0; i < entryValues.length; i++) {
                    if (entryValues[i].equals(value)) {
                        index = i;
                        break;
                    }
                }
                builder.append(entries[index]);
                if (pos < values.size())
                    builder.append(", ");
            }
            text = builder.toString();
        }
        summary = String.format(summary, text);
    }

    return summary;
}

Answer 2

至少在Kotlin中，您可以将函数添加到MultiSelectListPreference类中，如下所示：

import android.support.v14.preference.MultiSelectListPreference

fun MultiSelectListPreference.useSelectionAsSummary() {
    var summary = ""
    for (value in this.values) {
        if (summary.isNotEmpty()) {
            summary += ", "
        }
        val i = this.findIndexOfValue(value.toString())
        summary += this.entries[i]
    }
    this.summary = summary
}

用法如下：

prefSelectWeek.useSelectionAsSummary()

Answer 3

首先向MultiSelectListPreference添加一个扩展方法，该方法根据所选值设置摘要：

fun MultiSelectListPreference.setSummaryFromValues(values: Set<String>) {
    summary = values.map {entries[findIndexOfValue(it)]}.joinToString(", ")
}

然后在onCreateView中的PreferenceFragmentCompat：

val columnSelect = findPreference("EXPORT_COLUMNS") as MultiSelectListPreference
columnSelect.onPreferenceChangeListener = Preference.OnPreferenceChangeListener { preference, newValue ->
    columnSelect.setSummaryFromValues(newValue as Set<String>)
    true
}
columnSelect.setSummaryFromValues(columnSelect.values)

从multiselectlistpreference显示摘要中的选定值

3 个答案: