优雅地实现 Android Toolbar 及沉浸式状态栏

本文例子用了Toolbar，需要依赖support-v7

去除Actionbar

为方便地去除Actionbar，采用了自定义theme继承
"Theme.AppCompat.Light.NoActionBar"的方案

BaseActivity

public class BaseActivity extends AppCompatActivity {
    private static final String TAG = "BaseActivity";
    /**
     * Root view
     */
    private LinearLayout mRootLayout;
    /**
     * Toolbar instance
     */
    protected Toolbar mToolbar;

    public Toolbar getToolbar() {
        return mToolbar;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.activity_base);
        if (!isTaskRoot()) {
        /* If this is not the root activity,finish it.*/
            Intent intent = getIntent();
            String action = intent.getAction();
            if (intent.hasCategory(Intent.CATEGORY_LAUNCHER) && Intent.ACTION_MAIN.equals(action)) {
                //Logger.w("Activity is not the root.  Finishing Activity instead of launching.");
                Log.w(TAG, "Activity is not the root.  Finishing Activity instead of launching.");
                finish();
                return;
            }
        }
    }

    @Override
    public void setContentView(int layoutId) {
        setContentView(View.inflate(this, layoutId, null));
    }

    @Override
    public void setContentView(View view) {
        mRootLayout = (LinearLayout) findViewById(R.id.root_layout);
        if (mRootLayout == null) {
            return;
        }
        mRootLayout.addView(view,
                new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        initToolbar();
    }

    /**
     * 初始化Toolbar
     */
    private void initToolbar() {
        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        if (mToolbar != null) {
            showToolbar(true);
            //mToolbar.inflateMenu(R.menu.main);
            /** 设置支持ActionBar，当然也可以不这样做 */
            //setSupportActionBar(mToolbar);
            /** 去除ActionBar默认Title显示 */
            //getSupportActionBar().setDisplayShowTitleEnabled(false);
        }
    }

    /**
     * 显示Toolbar
     *
     * @param show true:显示,false:隐藏
     */
    public void showToolbar(boolean show) {
        if (mToolbar == null) {
            Log.e(TAG, "Toolbar is null.");
        } else {
            int paddingTop = mToolbar.getPaddingTop();
            int paddingBottom = mToolbar.getPaddingBottom();
            int paddingLeft = mToolbar.getPaddingLeft();
            int paddingRight = mToolbar.getPaddingRight();
            int statusHeight = ScreenUtil.getStatusHeight(this);
            ViewGroup.LayoutParams params = mToolbar.getLayoutParams();
            int height = params.height;
            /**
             * 利用状态栏的高度，4.4及以上版本给Toolbar设置一个paddingTop值为status_bar的高度，
             * Toolbar延伸到status_bar顶部
             **/
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                setTranslucentStatus(show);
                if (show) {
                    paddingTop += statusHeight;
                    height += statusHeight;
                } else {
                    paddingTop -= statusHeight;
                    height -= statusHeight;
                }
            }
            params.height = height;
            mToolbar.setPadding(paddingLeft, paddingTop, paddingRight, paddingBottom);
            mToolbar.setVisibility(show ? View.VISIBLE : View.GONE);
        }
    }

    /**
     * 设置透明状态栏
     * 对4.4及以上版本有效
     *
     * @param on
     */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    private void setTranslucentStatus(boolean on) {
        Window win = getWindow();
        WindowManager.LayoutParams winParams = win.getAttributes();
        final int bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
        if (on) {
            winParams.flags |= bits;
        } else {
            winParams.flags &= ~bits;
        }
        win.setAttributes(winParams);
    }
}

获取状态栏高度

   /**
     * 获得状态栏的高度
     *
     * @param context
     * @return px
     */
    public static int getStatusHeight(Context context) {

        int statusHeight = -1;
        try {
            Class clazz = Class.forName("com.android.internal.R$dimen");
            Object object = clazz.newInstance();
            int height = Integer.parseInt(clazz.getField("status_bar_height").get(object).toString());
            statusHeight = context.getResources().getDimensionPixelSize(height);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return statusHeight;
    }

BaseActivity布局

activity_base.xml

MainActivity

public class MainActivity extends BaseActivity implements OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            default:
                break;
        }
    }
}

MainActivity布局

activity_main.xml