可以自动完成 EditTextPreference 吗？

Question

是否可以有一个带有自动完成功能的 EditTextPreference 附加到它？

我知道如何将一个 ArrayAdapter 附加到具有 id 的元素，但我无法弄清楚如何将 ArrayAdapter 附加到首选项字段。

这是错误的，但这是我能得到的最接近的结果。

final String[] TEAMS = getResources().getStringArray(R.array.teams);   
AutoCompleteTextView EditTextPreference = (AutoCompleteTextView) findViewById(R.id.editTextPrefTeam);     
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_dropdown_item_1line, TEAMS);
EditTextPreference.setAdapter(adapter);

Answer 1

在我看来，必须有一种“更简单”的方法来完成此任务，而不是侵入 EditTextPreference 类并弄乱视图。这是我的解决方案，由于 AutoCompleteTextView 扩展了 EditText，我只需重写直接调用其常量 EditText 对象的 EditTextPreference 方法。

public class AutoCompletePreference extends EditTextPreference {

private static AutoCompleteTextView mEditText = null;

public AutoCompletePreference(Context context, AttributeSet attrs) {
    super(context, attrs);
    mEditText = new AutoCompleteTextView(context, attrs);
    mEditText.setThreshold(0);
    //The adapter of your choice
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(context, android.R.layout.simple_dropdown_item_1line, COUNTRIES);
    mEditText.setAdapter(adapter);
}
private static final String[] COUNTRIES = new String[] {
    "Belgium", "France", "Italy", "Germany", "Spain"
};

@Override
protected void onBindDialogView(View view) {
    AutoCompleteTextView editText = mEditText;
    editText.setText(getText());

    ViewParent oldParent = editText.getParent();
    if (oldParent != view) {
        if (oldParent != null) {
            ((ViewGroup) oldParent).removeView(editText);
        }
        onAddEditTextToDialogView(view, editText);
    }
}

@Override
protected void onDialogClosed(boolean positiveResult) {
    if (positiveResult) {
        String value = mEditText.getText().toString();
        if (callChangeListener(value)) {
            setText(value);
        }
    }
}
}

感谢布雷迪链接到来源。

Answer 2

这是我通过研究 EditTextPreference.java源代码。

本质上，您需要子类化 EditTextPreference 并在它绑定到对话框时进行覆盖。此时，您可以检索 EditText，复制其值，并将其从其父视图组中删除。然后注入 Autocompletetextview 并连接它的 Arrayadapter。

public class AutoCompleteEditTextPreference extends EditTextPreference
{
    public AutoCompleteEditTextPreference(Context context)
    {
        super(context);
    }

    public AutoCompleteEditTextPreference(Context context, AttributeSet attrs)
    {
        super(context, attrs);
    }

    public AutoCompleteEditTextPreference(Context context, AttributeSet attrs,
        int defStyle)
    {
        super(context, attrs, defStyle);
    }       

    /**
     * the default EditTextPreference does not make it easy to
     * use an AutoCompleteEditTextPreference field. By overriding this method
     * we perform surgery on it to use the type of edit field that
     * we want.
     */
    protected void onBindDialogView(View view)
    {
        super.onBindDialogView(view);

        // find the current EditText object
        final EditText editText = (EditText)view.findViewById(android.R.id.edit);
        // copy its layout params
        LayoutParams params = editText.getLayoutParams();
        ViewGroup vg = (ViewGroup)editText.getParent();
        String curVal = editText.getText().toString();
        // remove it from the existing layout hierarchy
        vg.removeView(editText);        
        // construct a new editable autocomplete object with the appropriate params
        // and id that the TextEditPreference is expecting
        mACTV = new AutoCompleteTextView(getContext());
        mACTV.setLayoutParams(params);
        mACTV.setId(android.R.id.edit);
        mACTV.setText(curVal);


        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(), 
             android.R.layout.simple_dropdown_item_1line, [LIST OF DATA HERE]);
        mACTV.setAdapter(adapter);

        // add the new view to the layout
        vg.addView(mACTV);
    }

    /**
     * Because the baseclass does not handle this correctly
     * we need to query our injected AutoCompleteTextView for
     * the value to save 
     */
    protected void onDialogClosed(boolean positiveResult) 
    {
        super.onDialogClosed(positiveResult);

        if (positiveResult && mACTV != null) 
        {           
            String value = mACTV.getText().toString();
            if (callChangeListener(value)) {
                setText(value);
            }
        }
    }

    /**
     * again we need to override methods from the base class
     */
    public EditText getEditText() 
    {
        return mACTV;
    }

    private AutoCompleteTextView mACTV = null;
    private final String TAG = "AutoCompleteEditTextPreference";
}

Answer 3

也许如果您对其进行子类化并为此创建自己的视图并使用 AutoCompleteTextView 对象作为元素，它就会起作用，因为目前我不知道如何将简单的 EditText 更改为自动完成。