Android9.0检测摄像头是否存在源码完整案例

关键代码如下，使用的是PackageManager去检查系统特性，其他设备也可以这样做的。
完整例子已在AndroidStudio3.5.2上运行通过：
PhoneTest.zip:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        PackageManager packageManager =  getApplicationContext().getPackageManager();
        boolean hasCamera = packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA) || packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT);
        if( hasCamera ){
            Toast.makeText(this,"摄像头已经准备好了",Toast.LENGTH_LONG).show();
        }else{
            Toast.makeText(this,"摄像头找不到",Toast.LENGTH_LONG).show();
        }
    }