Android開發時很多時候EditText 輸入框都需要一些 X 一類的清空按鈕，這樣就必須重寫EditText

public class UserPwdEditText extends EditText {

    private final String TAG = "MyEditText";
    private Drawable dRight;
    private Rect rBounds;

    public UserPwdEditText(Context paramContext) {
        super(paramContext);
        initEditText();
    }

    public
 
 UserPwdEditText(Context paramContext, AttributeSet paramAttributeSet) {
        super(paramContext, paramAttributeSet);
        initEditText();
    }

    public UserPwdEditText(Context paramContext,
            AttributeSet paramAttributeSet, int paramInt) {
        super(paramContext, paramAttributeSet, paramInt);
        initEditText();
    }

    // 初始化edittext 控制元件
 

    private void initEditText() {
        setEditTextDrawable();
        addTextChangedListener(new TextWatcher() { // 對文字內容改變進行監聽
            @Override
            public void afterTextChanged(Editable paramEditable) {
            }

            @Override
            public void beforeTextChanged(CharSequence paramCharSequence,
                    int
 
 paramInt1, int paramInt2, int paramInt3) {
            }

            @Override
            public void onTextChanged(CharSequence paramCharSequence,
                    int paramInt1, int paramInt2, int paramInt3) {
                UserPwdEditText.this.setEditTextDrawable();
            }
        });
    }

    // 控制圖片的顯示
    public void setEditTextDrawable() {
        if (getText().toString().length() == 0) {
            setCompoundDrawables(null, null, null, null);
        } else {
            setCompoundDrawables(null, null, this.dRight, null);
        }
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        this.dRight = null;
        this.rBounds = null;

    }

    /**
     * 新增觸控事件 點選之後 出現 清空editText的效果
     */
    @Override
    public boolean onTouchEvent(MotionEvent paramMotionEvent) {
        if ((this.dRight != null) && (paramMotionEvent.getAction() == 1)) {
            this.rBounds = this.dRight.getBounds();
            int i = (int) paramMotionEvent.getRawX();// 距離螢幕的距離
            // int i = (int) paramMotionEvent.getX();//距離邊框的距離
            if (i > getRight() - 3 * this.rBounds.width()) {
                setText("");
                paramMotionEvent.setAction(MotionEvent.ACTION_CANCEL);
            }
        }
        return super.onTouchEvent(paramMotionEvent);
    }

    /**
     * 顯示右側X圖片的
     * 
     * 左上右下
     */
    @Override
    public void setCompoundDrawables(Drawable paramDrawable1,
            Drawable paramDrawable2, Drawable paramDrawable3,
            Drawable paramDrawable4) {
        if (paramDrawable3 != null)
            this.dRight = paramDrawable3;
        super.setCompoundDrawables(paramDrawable1, paramDrawable2,
                paramDrawable3, paramDrawable4);
    }

}

佈局檔案是這樣的  要有一個圖片
<com.xinzhifu.view.UserPwdEditText
                android:id="@+id/login_edtPwd"
                android:layout_width="match_parent"
                android:layout_height="55dp"
                android:background="@null"
                android:drawableRight="@drawable/ic_delete"
                android:ems="10"
                android:hint="@string/pwd"
                android:inputType="textPassword"
                android:paddingLeft="15dp"
                android:paddingRight="15dp"
                android:singleLine="true"
                android:textColorHint="#999999"
                android:textSize="15sp" />