android 开发之 - 仿iOS searchBar 右边删除按钮

<RelativeLayout
        android:id="@+id/rlSearchFrameDelete"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:gravity="center_vertical" >

        <EditText
            android:id="@+id/etSearch"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginRight="10dp"
            android:background="@drawable/search_frame"
            android:hint="搜索"
            android:paddingLeft="32dp"
            android:singleLine="true"
            android:textSize="12sp" />

        <ImageView
            android:id="@+id/ivDeleteText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_centerInParent="true"
            android:paddingRight="20dp"
            android:src="@drawable/delete"
            android:visibility="gone" />
    </RelativeLayout>

etSearch.addTextChangedListener(new TextWatcher() {

            public void onTextChanged(CharSequence s, int start, int before,
                    int count) {
                // TODO Auto-generated method stub

            }

            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {
                // TODO Auto-generated method stub

            }

            public void afterTextChanged(Editable s) {
                if (s.length() == 0) {
                    ivDeleteText.setVisibility(View.GONE);
                } else {
                    ivDeleteText.setVisibility(View.VISIBLE);
                }
            }
        });

ivDeleteText.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                etSearch.setText("");
            }
        });