Android实战简易教程-第二十三枪（基于Baas的用户注冊验证username是否反复功能！）

接上一篇，加入验证用户名是否已经注冊功能！

仅仅须要改动MainActivity.java:

package com.example.logintest;

import java.util.List;

import org.w3c.dom.UserDataHandler;

import cn.bmob.v3.Bmob;
import cn.bmob.v3.BmobQuery;
import cn.bmob.v3.listener.FindListener;
import cn.bmob.v3.listener.SaveListener;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
	private EditText mUserName,mPassword;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Bmob.initialize(this, "8f3ffb2658d8a3366a70a0b0ca0b71b2");
		mUserName=(EditText) findViewById(R.id.et_username);
		mPassword=(EditText) findViewById(R.id.et_password);
	}
	public void submit(View view){
		final String username=mUserName.getText().toString();
		final String password=mPassword.getText().toString();
		if(username.equals("")||password.equals("")){
			Toast.makeText(this, "用户名或密码不能为空！", 3).show();
		}else{
			BmobQuery<User> query =new BmobQuery<User>();//查询类
			query.addWhereEqualTo("userName", username);//查询条件
			query.findObjects(MainActivity.this, new FindListener<User>() {

				@Override
				public void onSuccess(List<User> userlist) {
					if(userlist.size()==0){//查询不到，用户名可用
						User user=new User();
						user.setUserName(username);
						user.setUserPassword(password);
						user.save(MainActivity.this,new SaveListener() {

							@Override
							public void onSuccess() {
								Toast.makeText(MainActivity.this, "注冊成功！

", 3).show();

							}

							@Override
							public void onFailure(int arg0, String arg1) {
								Toast.makeText(MainActivity.this, "注冊失败！", 3).show();
							}
						});
					}else {
						Toast.makeText(MainActivity.this, "用户名已被注冊。", 3).show();
					}

				}

				@Override
				public void onError(int arg0, String arg1) {
					// TODO Auto-generated method stub

				}
			});

		}

	}

}

执行实比例如以下：

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