第一行代码——第七章：跨程序共享数据，探究内容提供者

1.Android 6.0 运行时获取权限

public class MainActivity extends AppCompatActivity {

    private Button btn_call;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_call = findViewById(R.id.btn_call);
        btn_call.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(ContextCompat.checkSelfPermission(MainActivity.this,
                        Manifest.permission.CALL_PHONE)!=PackageManager.PERMISSION_GRANTED)
                {
                    ActivityCompat.requestPermissions(MainActivity.this,
                            new String[]{Manifest.permission.CALL_PHONE},1);

                }else{
                    call();
                }
            }
        });
    }

    private void call() {
        try {
            Intent intent = new Intent(Intent.ACTION_CALL);
            intent.setData(Uri.parse("tel:10086"));
            startActivity(intent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode){
            case 1:
                if(grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION_GRANTED){
                    call();
                }else{
                    Toast.makeText(this,"You denied the permission",Toast.LENGTH_SHORT).show();
                }
                break;
            default:
        }
    }
}