简介

本文简单介绍使用EditText实现密码解锁
思路 ：
1.使用EditText接收用户输入
2.使用SharedPreference保存数据
3.使用Intent跳转界面

实现

1.在drawable中导入三张图片，在xml文件中配置如下

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/main_bg"/>

    <TextView
        android:id="@+id/alertText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="请设置密码"
        android:textColor="@color/colorGray"
        android:textSize="@dimen/dimen_alert"
        android:textAlignment="center"
        android:layout_marginTop="100dp"
        />

    <EditText
        android:id="@+id/et_password"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/unlock_normal"
        android:layout_centerHorizontal="true"
        android:layout_below="@+id/alertText"
        android:layout_marginTop="30dp"
        android:paddingLeft="50dp"
        android:textSize="@dimen/dimen_textView"
        android:inputType="textPassword"
        android:cursorVisible="false"
        android:letterSpacing="0.6"
        />

</RelativeLayout>

2.配置资源文件中的values
colors.xml中添加如下

<resources>
    <color name="colorPrimary">#008577</color>
    <color name="colorPrimaryDark">#00574B</color>
    <color name="colorAccent">#D81B60</color>
    <color name="colorGray">#999999</color>
    <color name="colorWhite">#ffffff</color>
</resources>

新建一个dimens.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="dimen_alert">30sp</dimen>
    <dimen name="dimen_textView">30sp</dimen>
</resources>

strings.xml中添加如下

<resources>
    <string name="app_name">PINUnlock</string>
    <string name="password_file_name">pwd</string>
    <string name="password_pwd_name">pwd</string>
</resources>

3.在MainActivity中实现

public class MainActivity extends AppCompatActivity {
    private TextView mTextView;
    private EditText mEditText;
    private SharedPreferences sp;
    private String password;
    private String firstInput;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 获取xml的控件
        mEditText = findViewById(R.id.et_password);
        mTextView = findViewById(R.id.alertText);

        //获取保存的密码
        sp = getSharedPreferences(getResources().getString(R.string.password_file_name),MODE_PRIVATE);
        //通过key获取对应的value
        password = sp.getString(getResources().getString(R.string.password_pwd_name), null);

        //显示提示文本
        if (password == null){
            mTextView.setText("请设置密码");
        }else {
            mTextView.setText("请输入密码");
        }

        //监听内容改变事件
        mEditText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void afterTextChanged(Editable editable) {
                String inputPassword = editable.toString();

                //判断是不是六个
                if (inputPassword.length() == 6){
                    //判断是不是设置密码
                    if (password == null){
                        //设置密码
                        if (firstInput == null){
                            firstInput = inputPassword;
                            // 提示确认密码
                            mTextView.setText("请确认密码");
                            //清空
                            mEditText.setText("");
                        }else {
                            //确认密码
                            if (firstInput.equals(inputPassword)){
                                //两次密码一致
                                mTextView.setText("密码设置成功");
                                //保存密码
                                SharedPreferences.Editor editor = sp.edit();
                                editor.putString(getResources().getString(R.string.password_pwd_name), firstInput);
                                editor.commit();
                                next();
                            }else {
                                //设置密码失败
                                mTextView.setText("两次密码不一致，请重新设置");
                                firstInput = null;
                                mEditText.setText("");
                            }
                        }
                    }else {
                        //密码设置过了
                        if (inputPassword.equals(password)){
                            //密码正确
                            mTextView.setText("密码正确");
                            //跳转界面
                            next();
                        }else {
                            //密码错误
                            mTextView.setText("密码错误");
                            // 清空
                            mTextView.clearComposingText();
                        }
                    }
                }
            }
        });
    }


    private void next(){
        //创建一个Intent确定跳转界面
        //1.显式意图  2.隐式意图（系统界面）
        Intent intent = new Intent(this,SecondActivity.class);
        startActivity(intent);
    }
}

4.在当前项目中新建一个activity并新建一个Layout的xml配置文件

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.MotionEvent;

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_activity);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        finish();
        return true;
    }
}

xml文件

<?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="match_parent">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/yan"/>

</RelativeLayout>

附件材料

main_bg.png

unlock_normal.png

yan.jpg