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<AVUser>() {
              @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