如何在 AutoCompleteTextView 中创建干净的按钮

Question

如何在 AutoCompleteTextView 中创建干净的按钮，当我单击清除按钮时，我想清除 AutoCompleteTextView 中的所有文本，见图

Answer 1

正如 Michael Derazon 在this post 中所解释的，您可以扩展 AutoCompleteTextView 以包含自定义清除功能。实现将如下所示：

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AutoCompleteTextView;

/**
 * sub class of {@link android.widget.AutoCompleteTextView} that includes a clear (dismiss / close) button with
 * a OnClearListener to handle the event of clicking the button
 * based on code from {@link http://www.gubed.net/clearableautocompletetextview}
 * @author Michael Derazon
 *
 */
public class ClearableAutoCompleteTextView extends AutoCompleteTextView {
    // was the text just cleared?
    boolean justCleared = false;

    // if not set otherwise, the default clear listener clears the text in the
    // text view
    private OnClearListener defaultClearListener = new OnClearListener() {

        @Override
        public void onClear() {
            ClearableAutoCompleteTextView et = ClearableAutoCompleteTextView.this;
            et.setText("");
        }
    };

    private OnClearListener onClearListener = defaultClearListener;

    // The image we defined for the clear button
    public Drawable imgClearButton = getResources().getDrawable(
            R.drawable.abc_ic_clear_holo_light);

    public interface OnClearListener {
        void onClear();
    }

    /* Required methods, not used in this implementation */
    public ClearableAutoCompleteTextView(Context context) {
        super(context);
        init();
    }

    /* Required methods, not used in this implementation */
    public ClearableAutoCompleteTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    /* Required methods, not used in this implementation */
    public ClearableAutoCompleteTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    void init() {
        // Set the bounds of the button
        this.setCompoundDrawablesWithIntrinsicBounds(null, null,
                imgClearButton, null);

        // if the clear button is pressed, fire up the handler. Otherwise do nothing
        this.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {

                ClearableAutoCompleteTextView et = ClearableAutoCompleteTextView.this;

                if (et.getCompoundDrawables()[2] == null)
                    return false;

                if (event.getAction() != MotionEvent.ACTION_UP)
                    return false;

                if (event.getX() > et.getWidth() - et.getPaddingRight() - imgClearButton.getIntrinsicWidth()) {
                    onClearListener.onClear();
                    justCleared = true;
                }
                return false;
            }
        });
    }

    public void setImgClearButton(Drawable imgClearButton) {
        this.imgClearButton = imgClearButton;
    }

    public void setOnClearListener(final OnClearListener clearListener) {
        this.onClearListener = clearListener;
    }

    public void hideClearButton() {
        this.setCompoundDrawables(null, null, null, null);
    }

    public void showClearButton() {
        this.setCompoundDrawablesWithIntrinsicBounds(null, null, imgClearButton, null);
    }

}

有关如何实现它的完整指南，请参阅full post。结果如下图：

Answer 2

试试这个：

activity_main.xml：

<FrameLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="10dp"
    android:padding="5dp">

    <AutoCompleteTextView
        android:layout_marginTop="20dp"
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:hint="type here..."
        android:dropDownWidth="300dp"/>

    <Button
        android:id="@+id/clear"
        android:layout_width="23dp"
        android:layout_height="23dp"
        android:layout_marginRight="10dp"
        android:layout_gravity="right|bottom"
        android:layout_marginBottom="10dp"
        android:background="@drawable/ic_close_black_24dp"
        android:onClick="clear"/>

</FrameLayout>

MainActivity.java：

public class MainActivity extends AppCompatActivity {

    AutoCompleteTextView text;
    Button clear;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        text = (AutoCompleteTextView) findViewById(R.id.text);

        clear = (Button) findViewById(R.id.clear);

        clear.setVisibility(View.INVISIBLE);

        //close button visibility for manual typing
        text.addTextChangedListener(new TextWatcher() {

            @Override
            public void afterTextChanged(Editable s) {
                //do nothing
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                //do nothing
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                if(s.length() != 0) {
                    clear.setVisibility(View.VISIBLE);
                } else {
                    clear.setVisibility(View.GONE);
                }
            }
        });

        //sample array
        String[] array = {"alpha", "beta", "cupcake", "donut", "eclair", "froyo", "gingerbread", "honeycomb", "icecreamsandwich", "jellybean", "kitkat", "lollipop", "marshmallow"};

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_dropdown_item,array);

        text.setThreshold(1);       //will start working from first character

        text.setAdapter(adapter);   //setting the adapter data into the AutoCompleteTextView

        //Shows drop down list on touch
        text.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View v, MotionEvent event){
                text.showDropDown();
                return false;
            }
        });

        //close button visibility for autocomplete text view selection
        text.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
                clear.setVisibility(View.VISIBLE);
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                clear.setVisibility(View.GONE);
            }

        });

    }

    public void clear(View view) {
        text.setText("");
        clear.setVisibility(View.GONE);
    }
}

Answer 3

<FrameLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1">

        <AutoCompleteTextView
            android:id="@+id/desart"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:textSize="15sp" />

        <ImageButton
            android:id="@+id/clean"
            android:layout_width="20dp"
            android:layout_height="20dp"
            android:adjustViewBounds="true"
            android:layout_gravity="right|center_vertical"
            android:background="@drawable/clean_state_button"
            android:scaleType="center"/>

 </FrameLayout>

Autocompletetextview with image button