在操作栏上显示后退按钮

Question

我正在尝试在上显示Back button，Action bar以将上一页/活动移动到主页（首次打开）。而且我做不到。

我的代码。

ActionBar actionBar = getActionBar();

actionBar.setHomeButtonEnabled(true);

代码在中onCreate。

Answer 1

好吧，这是一个简单的显示后退按钮的按钮actionBar.setDisplayHomeAsUpEnabled(true);然后您可以在onOptionsItemSelected上自定义back事件case android.R.id.home:this.finish();return true;

Answer 2

我认为onSupportNavigateUp()这样做是最好，最简单的方法，请检查以下步骤。步骤1是必要的，步骤2是替代方法。步骤1显示后退按钮：在onCreate()方法中添加此行以显示后退按钮。assert getSupportActionBar() != null;&nbsp; &nbsp;//null checkgetSupportActionBar().setDisplayHomeAsUpEnabled(true);&nbsp; &nbsp;//show back button步骤2的反向点击的实现：覆盖此方法@Overridepublic boolean onSupportNavigateUp(){&nbsp;&nbsp;&nbsp; &nbsp; finish();&nbsp;&nbsp;&nbsp; &nbsp; return true;&nbsp;&nbsp;}就是这样，您已经完成了，或者步骤2替代：您可以将meta添加到清单文件中的活动中，如下所示：<meta-data&nbsp; &nbsp; &nbsp; &nbsp; android:name="android.support.PARENT_ACTIVITY"&nbsp; &nbsp; &nbsp; &nbsp; android:value="MainActivity" />编辑：如果您不使用AppCompat活动，则不要使用support单词，可以使用getActionBar().setDisplayHomeAsUpEnabled(true); // In `OnCreate();`// And override this method@Override&nbsp;public boolean onNavigateUp(){&nbsp;&nbsp; &nbsp; &nbsp;finish();&nbsp;&nbsp; &nbsp; &nbsp;return true;&nbsp;}

Answer 3

魔术发生在onOptionsItemSelected。@Overridepublic boolean onOptionsItemSelected(MenuItem item) {&nbsp; &nbsp; switch (item.getItemId()) {&nbsp; &nbsp; &nbsp; &nbsp; case android.R.id.home:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // app icon in action bar clicked; go home&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Intent intent = new Intent(this, HomeActivity.class);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; startActivity(intent);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return true;&nbsp; &nbsp; &nbsp; &nbsp; default:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return super.onOptionsItemSelected(item);&nbsp; &nbsp; }}分享编辑