二、搜索蓝牙并连接(安卓蓝牙ble教程)
1、MainActivity.java
注:如果复制代码进项目时显示红色,请按ALT+ENTER键导包(import class)
package club.stm32;
import android.Manifest;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private BluetoothAdapter bluetoothAdapter;
private Button btnCheckPermission;
private TextView tvmsg;
private Button btnSearchBLE;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getPermission(); //获取权限
bluetoothInit(); //蓝牙初始化
widgetInit(); //控件初始化
widgetListener(); //控件监听
}
//获取权限
private void getPermission() {
//如果sdk版本大于23
if (Build.VERSION.SDK_INT >=23){
//如果没有权限
if ((ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED))
{
//动态申请权限
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 10);
}
}
}
//控件初始化
private void widgetInit() {
//请自行提升到全局,原型是:Button startscan = findViewById(R.id.startscan);
btnCheckPermission = findViewById(R.id.btnCheckPermission);
//请自行提升到全局,原型是:TextView tvmsg = findViewById(R.id.tvmsg);
tvmsg = findViewById(R.id.tvmsg);
//请自行提升到全局,原型是:Button btnSearchBLE = findViewById(R.id.btnSearchBLE);
btnSearchBLE = findViewById(R.id.btnSearchBLE);
}
//控件监听
private void widgetListener() {
//测试权限按钮监听
btnCheckPermission.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int permissionCheck = ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION);
if (permissionCheck == PackageManager.PERMISSION_GRANTED) {//如果有权限
Toast.makeText(MainActivity.this, "hava this permission", Toast.LENGTH_SHORT).show();//toast信息
Log.d("权限:","有定位权限");//在logcat上打印信息
tvmsg.setText("有定位权限");
}else {
getPermission();//获取权限
Toast.makeText(MainActivity.this, "no this permission", Toast.LENGTH_SHORT).show();//toast信息
Log.d("权限:","无定位权限");//在logcat上打印信息
tvmsg.setText("无定位权限");
}
}
});
//搜索蓝牙按钮监听
btnSearchBLE.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//开始搜索蓝牙
bluetoothAdapter.startLeScan(mBLEScanCallback);
}
});
}
//mBLEScanCallback回调函数
private BluetoothAdapter.LeScanCallback mBLEScanCallback = new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
//打印蓝牙mac地址
Log.d("BleMAC", device.getAddress());
}
};
private void bluetoothInit() {
//如果不支持蓝牙
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE))
{
//提示不支持蓝牙
Toast.makeText(this, "程序不支持该设备", Toast.LENGTH_SHORT).show();
//退出程序
finish();
}
//创建蓝牙适配器原型是BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
//如果蓝牙适配器为空
if (bluetoothAdapter == null)
{
//显示设备无蓝牙
Toast.makeText(this, "设备无蓝牙", Toast.LENGTH_SHORT).show();
//退出
finish();
}
//如果蓝牙未开启
if (!bluetoothAdapter.isEnabled())
{
//不提示,直接开启蓝牙
bluetoothAdapter.enable();
//提示开启蓝牙中
Toast.makeText(this, "开启蓝牙中,如果未开启,请检查应用权限", Toast.LENGTH_SHORT).show();
}
}
}
2、布局文件activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical"
tools:context=".MainActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="300dp"
android:text="Hello World!"
android:id="@+id/tvmsg"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="测试权限"
android:id="@+id/btnCheckPermission"
/>
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="搜索蓝牙"
android:id="@+id/btnSearchBLE"
/>
</LinearLayout>
</LinearLayout>
效果图:
注:如果你照我上面这样写,十有八九是搜不到蓝牙信息的,为什么呢,需要打开手机定位服务才能搜索到
另一种解决办法,是在build.gradle中配置如下信息
lintOptions {
checkReleaseBuilds false
abortOnError false
}
以及修改build.gradle中的targetSdkVersion ,修改到20或21可以解决定位权限问题
具体配置如下
apply plugin: 'com.android.application'
android {
lintOptions {
checkReleaseBuilds false
abortOnError false
}
compileSdkVersion 28
defaultConfig {
applicationId "club.stm32"
minSdkVersion 18
targetSdkVersion 21
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
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