記錄下一個很實用的小控制元件EditTextWithDel，就是在Android系統的輸入框右邊加入一個小圖示，點選小圖示可以清除輸入框裡面的內容，由於Android原生EditText不具備此功能，所以要想實現這一功能我們需要重寫EditText。
效果圖如下：

主要的思路就是為右邊的圖片設定監聽，點選右邊的圖片清除輸入框的內容並隱藏刪除圖示,因為我們不能直接給EditText設定點選事件，所以我們用記住我們按下的位置來模擬點選事件,用輸入框的的onTouchEvent()方法來模擬.

package com.xiaolijuan.edittextwithdeldome;

import
 
 android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.EditText;

/**
 * @author
 
: adan
 * @description: 自定義帶有刪除功能的EditText
 * @projectName: EditTextWithDelDome
 * @date: 2016-02-28
 * @time: 23:34
 */
public class EditTextWithDel extends EditText {
    private final static String TAG = "EditTextWithDel";
    private Drawable imgInable;
    private Drawable imgAble;
    private Context mContext;

    public
 
 EditTextWithDel(Context context) {
        super(context);
        mContext = context;
        init();
    }

    public EditTextWithDel(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mContext = context;
        init();
    }
    public EditTextWithDel(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        init();
    }

    private void init() {
        imgAble = mContext.getResources().getDrawable(
                R.mipmap.icon_delete_gray);
        addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int before,
                                      int count) {
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                                          int after) {
            }

            @Override
            public void afterTextChanged(Editable s) {
                setDrawable();
            }
        });
        setDrawable();
    }

    // 設定刪除圖片
    private void setDrawable() {
        if (length() < 1) {
            setCompoundDrawablesWithIntrinsicBounds(null, null, null, null);
        } else {
            setCompoundDrawablesWithIntrinsicBounds(null, null, imgAble, null);
        }
    }

    // 處理刪除事件
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (imgAble != null && event.getAction() == MotionEvent.ACTION_UP) {
            int eventX = (int) event.getRawX();
            int eventY = (int) event.getRawY();
            Log.e(TAG, "eventX = " + eventX + "; eventY = " + eventY);
            Rect rect = new Rect();
            getGlobalVisibleRect(rect);
            rect.left = rect.right - 50;
            if (rect.contains(eventX, eventY))
                setText("");
        }
        return super.onTouchEvent(event);
    }

    @Override
    protected void finalize() throws Throwable {
        super.finalize();
    }
}

setDrawable()方法，setCompoundDrawablesWithIntrinsicBounds(Drawable left, Drawable top, Drawable right, Drawable bottom)來在上、下、左、右設定圖示，如果不想在某個地方顯示，則設定為null。
接下來我們來使用它設定Activity的佈局，一個我們自定義的輸入框，一個按鈕

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_margin="25dp"
        android:background="#ffffff">

        <ImageView
            android:id="@+id/img"
            android:layout_width="25dp"
            android:layout_height="30dp"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:layout_margin="5dp"
            android:src="@mipmap/ic_launcher" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_alignParentBottom="true"
            android:layout_marginLeft="2dp"
            android:layout_marginRight="2dp"
            android:background="#56AB55" />

        <com.xiaolijuan.edittextwithdeldome.EditTextWithDel
            android:id="@+id/et_phoneNumber"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:layout_margin="2dp"
            android:layout_toRightOf="@+id/img"
            android:background="#ffffff"
            android:hint="請輸入手機號碼"
            android:maxLength="11"
            android:phoneNumber="true"
            android:singleLine="true" />
    </RelativeLayout>

    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="25dp"
        android:background="#56AB55"
        android:text="確定" />
</LinearLayout>

然後就是介面程式碼的編寫，主要測試下輸入框

package com.xiaolijuan.edittextwithdeldome;

import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends Activity {
    private EditText userName;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        userName = (EditText) findViewById(R.id.et_phoneNumber);
        findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (TextUtils.isEmpty(userName.getText().toString())){
                    Toast.makeText(getApplicationContext(),"手機號碼為空",Toast.LENGTH_LONG).show();
                    return;
                }
                Toast.makeText(getApplicationContext(),userName.getText().toString(),Toast.LENGTH_LONG).show();
            }
        });
    }
}