Android实战简易教程-第七十枪（自定义实用控制之-邮箱验证EditText）

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="46dp"
    android:background="@android:color/white" >

    <EditText
        android:id="@+id/edittext"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/bg_edittext"
        android:paddingLeft="50dp" />

    <RelativeLayout
        android:layout_width="46dp"
        android:layout_height="match_parent" >

        <ImageView
            android:id="@+id/image"
            android:layout_width="22dp"
            android:layout_height="30dp"
            android:layout_centerInParent="true"
            android:scaleType="centerInside" />
    </RelativeLayout>

</RelativeLayout>

package com.example.drawableedittext;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.content.Context;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.RelativeLayout;

public class DrawableEditText extends RelativeLayout {

	private Context mContext;
	private EditText mEditText;
	private ImageView mImage;
	public DrawableEditText(Context context, AttributeSet attrs) {
		super(context, attrs);
		this.mContext = context;
		init();
		// 设置文字大小
		int textSize = attrs.getAttributeResourceValue(null, "textSize", 0);
		if (textSize != 0) {
			mEditText.setTextSize(textSize);
		}

// 设置edittext的hint提示
		int hint = attrs.getAttributeResourceValue(null, "hint", 0);
		if (hint != 0) {
			mEditText.setHint(hint);
		}

		// 设置文本颜色
		int textColor = attrs.getAttributeResourceValue(null, "textColor", 0);
		if (textColor != 0) {
			mEditText.setTextColor(textColor);
		}
	}
	// 初始化布局和控件
	public void init() {
		LayoutInflater inflater = LayoutInflater.from(mContext);
		View view = inflater.inflate(R.layout.drawable_edittext, this);
		mEditText = (EditText) view.findViewById(R.id.edittext);
		mImage = (ImageView) view.findViewById(R.id.image);
	}
	// 根据文本框是否为空设置不同的图片
	private void setDrawable() {
		if (checkEmail(mEditText.getText().toString())) {
			mImage.setImageResource(R.drawable.right);
			//mImage.setImageResource(nullImgRes);
		} else {
			//mImage.setImageResource(imgRes);
			mImage.setImageResource(R.drawable.close);
		}
	}
	@Override
	protected void onFinishInflate() {
		super.onFinishInflate();
		// 文本框的text改变监听
		mEditText.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();
			}
		});
	}
	/**
	 * 验证邮箱
	 * 
	 * @param email
	 * @return
	 */
	public static boolean checkEmail(String email) {
		boolean flag = false;
		try {
			String check = "^([a-z0-9A-Z]+[-|_|\\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\\.)+[a-zA-Z]{2,}$";
			Pattern regex = Pattern.compile(check);
			Matcher matcher = regex.matcher(email);
			flag = matcher.matches();
		} catch (Exception e) {
			flag = false;
		}
		return flag;
	}

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginLeft="20dp"
    android:layout_marginRight="20dp" >

    <com.example.drawableedittext.DrawableEditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        imgRes="@drawable/phonenumber_click"
        nullImgRes="@drawable/phonenumber" />

</RelativeLayout>