登录无判断操作

在登录时没有进行判断操作

LoginActivity.java

package com.example.tasks;

import org.w3c.dom.Text;

import com.avos.avoscloud.AVException;
import com.avos.avoscloud.AVUser;
import com.avos.avoscloud.LogInCallback;

import android.R.string;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class LoginActivity extends Activity {
TextView LoginName;
TextView LoginPwd;
Button Login;
TextView Regist1;
String LN;
String LP;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
LoginName=(TextView) findViewById(R.id.LoginName);
LoginPwd=(TextView) findViewById(R.id.LoginPwd);
Login=(Button) findViewById(R.id.Login);
Regist1=(TextView) findViewById(R.id.Regist1);

// 修改状态栏颜色，4.4+生效
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
setTranslucentStatus();
}
SystemBarTintManager tintManager = new SystemBarTintManager(this);
tintManager.setStatusBarTintEnabled(true);
tintManager.setStatusBarTintResource(R.drawable.iphone);//通知栏所需颜色

Login.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(LN.length() <=0){
Toast.makeText(getApplicationContext(),"用户名不能为空",Toast.LENGTH_SHORT).show();
return;
}
if (LP.length()<= 0) {
Toast.makeText(getApplicationContext(), "密码不能为空", Toast.LENGTH_SHORT).show();
return;
}

LN=LoginName.getText().toString();
LP=LoginPwd.getText().toString();

AVUser.logInInBackground(LN, LP, new LogInCallback() {
@Override
public void done(AVUser avUser, AVException e) {

if (avUser!=null) {
Intent intent=new Intent(LoginActivity.this, MainActivity.class);
startActivity(intent);
finish();

}

}
});

}
});

Regist1.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent=new Intent(LoginActivity.this,RegistActivity.class);
startActivity(intent);

}
});
}

private void setTranslucentStatus() {

Window window = this.getWindow();
// Translucent status bar
window.setFlags(
WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS,
WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
}
}
加入这段登录判断语句即可