删除片段

Question

每次打开片段时，它都会被添加到堆栈中。 所以，后退按钮会根据堆栈返回给我。

我想每次打开片段时都要删除堆栈。

如果是的话，我怎么能这样做？ 这是我的代码

public class MainActivity extends AppCompatActivity {

    private FragmentManager fragmentManager;
    FragmentTransaction transaction;

    LinearLayout firstColumn,secondColumn,thirdColumn;

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

        fragmentManager = getSupportFragmentManager();

        firstColumn = (LinearLayout) findViewById(R.id.first_column);
        secondColumn = (LinearLayout) findViewById(R.id.second_column);

        firstColumn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                    transaction = getSupportFragmentManager().beginTransaction();
                    transaction.replace(R.id.main_container_frame_layout, new FirstFragment());

                    transaction.commit();

            }
        });

        secondColumn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                transaction = getSupportFragmentManager().beginTransaction();
                transaction.replace(R.id.main_container_frame_layout, new SecondFragment());

                transaction.commit();
            }
        });



    }
}

提前谢谢。

Answer 1

getSupportFragmentManager（）。popBackStack（）将根据堆栈返回。下面的代码可以帮到你。

  @Override
    public void onBackPressed() {

        if(getSupportFragmentManager().getBackStackEntryCount() > 0) {
            getSupportFragmentManager().popBackStack();
        }else 
            super.onBackPressed();
}