AndroidStudio登錄界面

AndroidStudio 3.1.4

1.創建一個新的項目，項目名為Login，布局界面為activity_login.xml，打開布局界面進行布局

2.需要用到四個TextView一個Plain Text一個Password一個Button

3.設置Button的onClick為thisButtonLogin

4.用戶名編輯框ID設置為userEdit，密碼編輯框ID設置為passworEdit

5.打開java\com.包名.login\Login撰寫代碼

6.代碼如下

　　首先需要一個函數接受按鈕按下事件

public void thisButtonLogin(View view){
    
}

　　獲取用戶輸入的賬號和密碼內容

        EditText editText = (EditText)findViewById(R.id.userEdit);
        String user = editText.getText().toString();
        editText = (EditText)findViewById(R.id.passwordEdit);
        String pw = editText.getText().toString();

　　判斷兩個編輯框的內容是否為空

        if (user == null || user.length() == 0) {
            AlertDialog.Builder usermessage=new AlertDialog.Builder(this);
            usermessage.setMessage("用戶名不能為空！");
            usermessage.setPositiveButton("確定",click1);
            AlertDialog usermessage1=usermessage.create();
            usermessage1.show();
        }else if(pw == null || pw.length() == 0) {
            AlertDialog.Builder pwmessage=new AlertDialog.Builder(this);
            pwmessage.setMessage("密碼不能為空！");
            pwmessage.setPositiveButton("確定",click1);
            AlertDialog pwmessage1=pwmessage.create();
            pwmessage1.show();
        }

　　彈出信息框，顯示用戶輸入的賬號和密碼

            //彈出信息框，顯示用戶輸入的賬號和密碼
            AlertDialog.Builder winmessage = new AlertDialog.Builder(this);
            winmessage.setMessage("賬號:"+user+"\n"+"密碼:"+pw);
            winmessage.setPositiveButton("確定",click2);
            AlertDialog winmessage2 = winmessage.create();
            winmessage2.show();

　　賬號或密碼為空時彈出的信息框按鈕上的確定按鈕被按下時觸發的事件

    private DialogInterface.OnClickListener click1 = new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    };

　　輸入用戶輸入的賬號和密碼的信息框按鈕上的確定按鈕被按下時觸發的事件

    private DialogInterface.OnClickListener click2 = new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            android.os.Process.killProcess(android.os.Process.myPid());
        }
    };

7.最終代碼效果如下

package com.shawna.login;

import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class Login extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
    }
    public void thisButtonLogin(View view){
        //接收按鈕按下事件

        //獲取用戶輸入的賬號和密碼
        EditText editText = (EditText)findViewById(R.id.userEdit);
        String user = editText.getText().toString();
        editText = (EditText)findViewById(R.id.passwordEdit);
        String pw = editText.getText().toString();

        //這一段是測試的遺留的，用來在判斷前輸出輸入的賬號內容
        //AlertDialog.Builder message = new AlertDialog.Builder(this);
        //message.setMessage(user);
        //message.setPositiveButton("確定",click1);
        //AlertDialog message1 = message.create();
        //message1.show();

        //判斷兩個編輯框內容是否為空
        if (user == null || user.length() == 0) {
            AlertDialog.Builder usermessage=new AlertDialog.Builder(this);
            usermessage.setMessage("用戶名不能為空！");
            usermessage.setPositiveButton("確定",click1);
            AlertDialog usermessage1=usermessage.create();
            usermessage1.show();
        }else if(pw == null || pw.length() == 0) {
            AlertDialog.Builder pwmessage=new AlertDialog.Builder(this);
            pwmessage.setMessage("密碼不能為空！");
            pwmessage.setPositiveButton("確定",click1);
            AlertDialog pwmessage1=pwmessage.create();
            pwmessage1.show();
        }else{
            //彈出信息框，顯示用戶輸入的賬號和密碼
            AlertDialog.Builder winmessage = new AlertDialog.Builder(this);
            winmessage.setMessage("賬號:"+user+"\n"+"密碼:"+pw);
            winmessage.setPositiveButton("確定",click2);
            AlertDialog winmessage2 = winmessage.create();
            winmessage2.show();
        }
    }
    private DialogInterface.OnClickListener click1 = new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    };
    private DialogInterface.OnClickListener click2 = new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            android.os.Process.killProcess(android.os.Process.myPid());
        }
    };
}

8.編寫完成后就可以進行調試了！Lucky~