Android studio 实现手机扫描二维码功能

<!-- 获取手机相机的权限 -- 
  <uses-permission android:name="android.permission.CAMERA" / 
  <uses-permission android:name="android.permission.FLASHLIGHT" / 

<?xml version="1.0" encoding="utf-8"? 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="wrap_content"
  android:layout_gravity="center"
  android:layout_height="wrap_content" 

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="开启相机扫描"
    android:id="@+id/btn"
    / 
</LinearLayout 

package com.example.a86156.saomiao;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.uuzuche.lib_zxing.activity.CaptureActivity;
import com.uuzuche.lib_zxing.activity.CodeUtils;
import com.uuzuche.lib_zxing.activity.ZXingLibrary;
public class MainActivity extends AppCompatActivity {
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//隐藏系统默认的标题
ActionBar actionBar = getSupportActionBar();
if(actionBar!=null){
actionBar.hide();
}
//初始化相机权限
ZXingLibrary.initDisplayOpinion(this);
btn = findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//先判断手机版本是否在6.0以上，如果在6.0以上则需要动态申请权限
if (Build.VERSION.SDK_INT   22) {
if (ContextCompat.checkSelfPermission(MainActivity.this,
android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
//先判断有没有权限 ，没有就在这里进行权限的申请
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{android.Manifest.permission.CAMERA}, 1);
} else {
//说明已经获取到摄像头权限了 想干嘛干嘛
Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
startActivityForResult(intent, 1);
}
} else {
//这个说明系统版本在6.0之下，不需要动态获取权限。
Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
startActivityForResult(intent, 1);
}
}
});
}
//获取手机相机权限
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == 1) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Intent intent = new Intent(this, CaptureActivity.class);
startActivityForResult(intent, 1);
} else {
Toast.makeText(MainActivity.this, "请打开相机权限", Toast.LENGTH_SHORT).show();
}
}
}
//处理扫描结果
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (data != null) {
Bundle bundle = data.getExtras();
if (bundle == null) {
return;
}
if (bundle.getInt(CodeUtils.RESULT_TYPE) == CodeUtils.RESULT_SUCCESS) {
//获取到扫描的结果
String result = bundle.getString(CodeUtils.RESULT_STRING);
Log.d("res:",result);
}
}
}
}
}