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);
        }
      }
    }
  }
}