我百度了一下关于应用锁的内容，大部分都是用service来实现，作为一个入门的人来说，用service来做一个的确有点难度。现在有一种比较简单的方法，总得来说就是用一个值来记录这次返回或者打开Activity是否是由按键打开，是的话则不弹出锁屏，不是的话则弹出锁屏，我们这次用sharepreference来储存这个值
一、我们先新建一个BaseActivity，因为这些Activity都是在onResume判断是否为按键打开或返回
public class BaseActivity extends AppCompatActivity {
public SharedPreferences sharedPreferences;
public SharedPreferences.Editor editor;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sharedPreferences=getSharedPreferences("sp",MODE_PRIVATE);//sp为sharepreference名字
editor=sharedPreferences.edit();
}
@Override
protected void onResume() {
super.onResume();
//如果lock值是false是真的就弹出锁屏，假的话就设为真
if (sharedPreferences.getBoolean("lock",false)){
startActivity(new Intent(BaseActivity.this,LockActivity.class));
editor.putBoolean("lock",false);
editor.commit();
}else {
editor.putBoolean("lock",true);
editor.commit();
}
}
//按返回键时将lock设为假
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK){
editor.putBoolean("lock",false);
editor.commit();
}
return super.onKeyDown(keyCode, event);
}
}
二、新建Activity继承自BaseActivity
package com.jkgeekjack.newlock;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends BaseActivity {
private Button button;
private Button button1;
private Button button2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button= (Button) findViewById(R.id.button);
button1= (Button) findViewById(R.id.button2);
button2= (Button) findViewById(R.id.button3);
//点击跳转时将lock值设为假
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this,Main2Activity.class));
editor.putBoolean("lock",false);
editor.commit();
}
});
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this,Main3Activity.class));
editor.putBoolean("lock",false);
editor.commit();
}
});
//点击finish时将lock值设为假
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
editor.putBoolean("lock",false);
editor.commit();
finish();
}
});
}
}
其他Activity基本和这个是一样的，都是继承自BaseActivity，有按键点击跳转或者返回时将lock值设为假
三、新建锁界面
锁界面的逻辑代码
package com.jkgeekjack.newlock;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class LockActivity extends Activity implements View.OnClickListener {
private TextView tv1;
private TextView tv2;
private TextView tv3;
private TextView tv4;
private TextView tv5;
private TextView tv6;
private TextView tv7;
private TextView tv8;
private TextView tv9;
private TextView tv0;
private TextView tvCancle;
private ImageView ivCircle1;
private ImageView ivCircle2;
private ImageView ivCircle3;
private ImageView ivCircle4;
private String insertPwd;
private List circles=new ArrayList();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lock);
initView();
initListener();
}
private void initListener() {
tv0.setOnClickListener(this);
tv1.setOnClickListener(this);
tv2.setOnClickListener(this);
tv3.setOnClickListener(this);
tv4.setOnClickListener(this);
tv5.setOnClickListener(this);
tv6.setOnClickListener(this);
tv7.setOnClickListener(this);
tv8.setOnClickListener(this);
tv9.setOnClickListener(this);
tvCancle.setOnClickListener(this);
}
private void initView() {
tv0= (TextView) findViewById(R.id.tv0);
tv1= (TextView) findViewById(R.id.tv1);
tv2= (TextView) findViewById(R.id.tv2);
tv3= (TextView) findViewById(R.id.tv3);
tv4= (TextView) findViewById(R.id.tv4);
tv5= (TextView) findViewById(R.id.tv5);
tv6= (TextView) findViewById(R.id.tv6);
tv7= (TextView) findViewById(R.id.tv7);
tv8= (TextView) findViewById(R.id.tv8);
tv9= (TextView) findViewById(R.id.tv9);
tv0= (TextView) findViewById(R.id.tv0);
tvCancle= (TextView) findViewById(R.id.tvCancle);
ivCircle1= (ImageView) findViewById(R.id.ivCircle1);
ivCircle2= (ImageView) findViewById(R.id.ivCircle2);
ivCircle3= (ImageView) findViewById(R.id.ivCircle3);
ivCircle4= (ImageView) findViewById(R.id.ivCircle4);
circles.add(ivCircle1);
circles.add(ivCircle2);
circles.add(ivCircle3);
circles.add(ivCircle4);
clearCircle();
insertPwd="";
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.tv0:addToPwd(0);break;
case R.id.tv1:addToPwd(1);break;
case R.id.tv2:addToPwd(2);break;
case R.id.tv3:addToPwd(3);break;
case R.id.tv4:addToPwd(4);break;
case R.id.tv5:addToPwd(5);break;
case R.id.tv6:addToPwd(6);break;
case R.id.tv7:addToPwd(7);break;
case R.id.tv8:addToPwd(8);break;
case R.id.tv9:addToPwd(9);break;
case R.id.tvCancle:
if (insertPwd.length()>0){
insertPwd=insertPwd.substring(0,insertPwd.length()-1);
}
updateUi();
break;
}
}
//每输入一位刷新一次UI
public void addToPwd(int num){
insertPwd+=num;
updateUi();
//满4位确认是否为正确密码
if (insertPwd.length()==4){
comfirmPwd();
}
}
private void comfirmPwd() {
String pwd="1234";
if (pwd.equals(insertPwd)){
Toast.makeText(LockActivity.this,"密码正确",Toast.LENGTH_SHORT).show();
finish();
}else {
Toast.makeText(LockActivity.this,"密码错误",Toast.LENGTH_SHORT).show();
}
insertPwd="";
clearCircle();
}
//清空圆点
private void clearCircle() {
for (ImageView circle:circles){
circle.setVisibility(View.INVISIBLE);
}
}
public void updateUi(){
clearCircle();
for (int i=0;i 注意，锁界面是不继承自BaseActivity的