Android结合ButterKnife创建自己的BaseActivity(兼容6.0)

在Android开发中，我们需要创建一个BaseActivity来方便对APP中所有的activity进行统一操作。今天我们就来说说如何结合ButterKnife来打造一个加强版的BaseActivity。不熟悉ButterKnife的朋友可以参考我这篇文章 Android之ButterKnife用法详解 。

BaseActivity

public abstract class BaseActivity extends AppCompatActivity {


    private Unbinder mUnbinder;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(getContentViewResId());
        mUnbinder = ButterKnife.bind(this);

        init(savedInstanceState);
    }

    public abstract int getContentViewResId();

    public abstract void init(Bundle savedInstanceState);

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mUnbinder.unbind();
    }

}

因为我们的ButterKnife在每个Activity中的绑定与解绑操作都是一样的，所以将其封装成一个BaseActivity抽象类。再来看看我们的使用：

public class TestActivity extends BaseActivity {
    @BindView(R.id.tv_test)
    TextView mTextView;

    @Override
    public int getContentViewResId() {
        // 此处返回你Activity的contentViewId
        return R.layout.activity_test;
    }

    @Override
    public void init(Bundle savedInstanceState) {
        // 此处进行初始化操作
    }
}

是不是加入了ButterKnife之后，我们使用起来就特别方便了

接下来看看BaseFragment

public abstract class BaseFragment extends Fragment {

    public static final String TAG = BaseFragment.class.getSimpleName();
    private View mRootView;
    private Unbinder mUnbinder;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        mRootView = inflater.inflate(getLayoutResId(), container, false);
        mUnbinder = ButterKnife.bind(this, mRootView);
        init(savedInstanceState);
        return mRootView;
    }

    public abstract void init(Bundle savedInstanceState);

    public abstract int getLayoutResId();

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        mUnbinder.unbind();
    }
}

其实BaseActivity跟BaseFragment的差别不大，唯一就是在ButterKnife在初始化需要有点不同。这里不再过多阐述。接下来我们说说终极版的兼容6.0权限操作的BaseActivity。

终极版兼容6.0运行时权限的BaseActivity

public abstract class BaseActivity extends AppCompatActivity implements ActivityCompat.OnRequestPermissionsResultCallback {


    private Unbinder mUnbinder;


    /**
     * 需要进行检测的权限数组
     */
    protected String[] mNeedPermissions = {
            // 这里填你需要申请的权限
            // 如：读取sd卡
            Manifest.permission.WRITE_EXTERNAL_STORAGE,
            Manifest.permission.READ_EXTERNAL_STORAGE,
    };


    private static final int PERMISSION_REQUEST_CODE = 0;


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(getContentViewResId());
        mUnbinder = ButterKnife.bind(this);

        checkPermissions(mNeedPermissions);
        init(savedInstanceState);
    }

    /**
     * @param permissions
     */
    private void checkPermissions(String... permissions) {
        List needRequestPermissionList = findDeniedPermissions(permissions);
        if (null != needRequestPermissionList
                && needRequestPermissionList.size() > 0) {
            ActivityCompat.requestPermissions(this,
                    needRequestPermissionList.toArray(
                            new String[needRequestPermissionList.size()]),
                    PERMISSION_REQUEST_CODE);
        }
    }


    /**
     * 获取权限集中需要申请权限的列表
     *
     * @param permissions
     * @return
     */
    private List findDeniedPermissions(String[] permissions) {
        List needRequestPermissionList = new ArrayList();
        for (String perm : permissions) {
            if (ContextCompat.checkSelfPermission(this, perm) != PackageManager.PERMISSION_GRANTED
                    || ActivityCompat.shouldShowRequestPermissionRationale(this, perm)) {
                needRequestPermissionList.add(perm);
            }
        }
        return needRequestPermissionList;
    }


    /**
     * 检测是否说有的权限都已经授权
     *
     * @param grantResults
     * @return
     */
    private boolean verifyPermissions(int[] grantResults) {
        for (int result : grantResults) {
            if (result != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }


    /**
     * 显示提示信息
     *
     */
    private void showMissingPermissionDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle(R.string.notifyTitle);
        builder.setMessage(R.string.notifyMsg);

        // 拒绝, 退出应用
        builder.setNegativeButton(R.string.cancel,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                });

        builder.setPositiveButton(R.string.setting,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        startAppSettings();
                    }
                });

        builder.setCancelable(false);

        builder.show();
    }


    /**
     * 启动应用的设置
     *
     */
    private void startAppSettings() {
        Intent intent = new Intent(
                Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
        intent.setData(Uri.parse("package:" + getPackageName()));
        startActivity(intent);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == PERMISSION_REQUEST_CODE) {
            if (!verifyPermissions(grantResults)) {
                showMissingPermissionDialog();
            }
        }
    }

    public abstract int getContentViewResId();

    public abstract void init(Bundle savedInstanceState);

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mUnbinder.unbind();
    }

}

解释一下代码：1.首先我们在 onCreate中通过checkPermissions(mNeedPermissions)检查我们需要的权限，在checkPermissions中会调用findDeniedPermissions来寻找我们哪些权限是需要去申请的，然后调用ActivityCompat.requestPermissions去申请权限，申请权限会在onRequestPermissionsResult中回到，我们再调用verifyPermissions来确认是否所有的权限已被准许，如果没有调用showMissingPermissionDialog来告知用户权限确实。
最后我们在使用的时候只需要继承BaseActivity，重写mNeedPermissions这个成员变量即可。而不需要每次在需要申请权限的Activity里面写一大堆臃肿的代码。BaseFragment与BaseActivity同理哟!