ZXing+LeakCanary使用

一.生成二维码和扫描二维码

1.依赖：

implementation 'cn.yipianfengye.android:zxing-library:2.2'

2.权限：

<!--网络权限-->
    <uses-permission android:name="android.permission.INTERNET"/>
    <!--震动权限-->
    <uses-permission android:name="android.permission.VIBRATE"/>
    <!--摄像头权限-->
    <uses-permission android:name="android.permission.CAMERA"/>
    <!--自动聚焦权限-->
    <uses-feature android:name="android.hardware.camera.autofocus"/>

3.动态权限：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            requestPermissions(new String[]{Manifest.permission.CAMERA,Manifest.permission.VIBRATE,Manifest.permission.WRITE_EXTERNAL_STORAGE}, 200);
        }

4.application初始化ZXing：

创建一个App

public class App extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        //初始化Zxing库
        ZXingLibrary.initDisplayOpinion(this);
    }
}

5.清单文件：

记得在清单文件中去声明App

android:name=".App"

6.生成二维码：

bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
                Bitmap code = CodeUtils.createImage("你好呀", 400, 400, bitmap);
                iv.setImageBitmap(code);
            }
        });

7.扫描二维码：

bt1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
                startActivityForResult(intent,101);
            }
        });

@Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 101 && resultCode == Activity.RESULT_OK){
            Bundle extras = data.getExtras();
            if (extras != null){
                String string = extras.getString(CodeUtils.RESULT_STRING);
                Toast.makeText(this, "扫描结果"+string, Toast.LENGTH_SHORT).show();
            }
        }
    }

8.所有代码：

import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import com.uuzuche.lib_zxing.activity.CaptureActivity;
import com.uuzuche.lib_zxing.activity.CodeUtils;

public class MainActivity extends AppCompatActivity {

    private Button bt;
    private ImageView iv;
    private Button bt1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            requestPermissions(new String[]{Manifest.permission.CAMERA, Manifest.permission.VIBRATE, Manifest.permission.WRITE_EXTERNAL_STORAGE}, 200);
        }
        initView();
        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
                Bitmap code = CodeUtils.createImage("你好呀", 400, 400, bitmap);
                iv.setImageBitmap(code);
            }
        });
        bt1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
                startActivityForResult(intent,101);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 101 && resultCode == Activity.RESULT_OK){
            Bundle extras = data.getExtras();
            if (extras != null){
                String string = extras.getString(CodeUtils.RESULT_STRING);
                Toast.makeText(this, "扫描结果"+string, Toast.LENGTH_SHORT).show();
            }
        }

    }

    private void initView() {
        bt = (Button) findViewById(R.id.bt);
        iv = (ImageView) findViewById(R.id.iv);
        bt1 = (Button) findViewById(R.id.bt1);
    }
}

二.LeakCanary内存泄漏

1.什么是LeakCanary

LeakCanary是大名鼎鼎的square公司开源的内存泄漏检测工具，目前上大部分app在开发测试阶段都会接入此工具用于检测潜在的内存泄漏问题。

2.依赖：

//导入LeakCanary的依赖，去定位页面的内存泄漏问题。
    debugImplementation 'com.squareup.leakcanary:leakcanary-android:1.6.3'
    releaseImplementation 'com.squareup.leakcanary:leakcanary-android-no-op:1.6.3'
    debugImplementation 'com.squareup.leakcanary:leakcanary-support-fragment:1.6.3'

3.application中部署：

在App里面，如上

//部署leakcanary,定位内存泄漏
        if(!LeakCanary.isInAnalyzerProcess(this)){//如果没有部署
            LeakCanary.install(this);//部署
        }

4.制造内存泄漏现象：

/***
 单例模式的TestManager
 */
public class TestManager {
    private List<Activity> list = new ArrayList<>();
    private static TestManager testManager;
    public static TestManager getInstance(){
        if(testManager == null){
            testManager = new TestManager();
        }
        return testManager;
    }
    public void add(Activity activity){
        list.add(activity);
    }
}

然后创建两个LeakActivity

public class LeakActivity extends AppCompatActivity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_leak);
     findViewById(R.id.bt).setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View view) {
             Intent intent = new Intent(LeakActivity.this,Leak2Activity.class);
             startActivity(intent);

         }
     });
 }
}

public class Leak2Activity extends AppCompatActivity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_leak2);
     TestManager.getInstance().add(this);
 }
}

跳转以后会出现一个Leaks的图标
点击进去可以查看内存泄漏原因