Android：AutoCompleteTextView 在未输入文本时显示建议

    android:id="@+id/autoCompleteTextView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="请输入文本"
    android:completionThreshold="1" />

// 获取AutoCompleteTextView控件的实例
AutoCompleteTextView autoCompleteTextView = findViewById(R.id.autoCompleteTextView);
// 创建建议的数据源
String[] suggestions = {"Apple", "Banana", "Cherry", "Durian", "Elderberry", "Fig"};
// 创建ArrayAdapter并关联数据源和AutoCompleteTextView控件
ArrayAdapter adapter = new ArrayAdapter<>(this,
        android.R.layout.simple_dropdown_item_1line, suggestions);
autoCompleteTextView.setAdapter(adapter);