eclypse：片段事务类型中的add（int片段）方法不适用

Question

我开始Android开发和学习Java。 我的问题是“在类型fragmenttransaction中的方法add（int片段）不适用”错误

     package com.example.myfirstapp;
    import android.annotation.SuppressLint;
    import android.annotation.TargetApi;
    import android.app.Fragment;
    import android.os.Build;
    import android.os.Bundle;
    import android.support.v7.app.ActionBarActivity;
    import android.view.LayoutInflater;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.ViewGroup;
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    @SuppressLint("NewApi")
    public class DisplayMessageActivity extends ActionBarActivity {
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_display_message);

            if (savedInstanceState == null) {
                getSupportFragmentManager().beginTransaction()
   <==here==>             .add(R.id.container, new PlaceholderFragment()).commit();
            }
        }
        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            int id = item.getItemId();
            if (id == R.id.action_settings) {
                return true;
            }
            return super.onOptionsItemSelected(item);
        }

        public static class PlaceholderFragment extends Fragment {
            public PlaceholderFragment() { }
            @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container,
                      Bundle savedInstanceState) {
                  View rootView = inflater.inflate(R.layout.activity_display_message,
                          container, false);
                  return rootView;
            }
        }
    }

当我使用import android.support.v4.app.Fragment; elypse没有显示任何错误，但在我的手机应用程序崩溃了感谢您的帮助！

Answer 1

如果仅使用android.support.v4.app.Fragment，则可以使用getSupportFragmentManager（）。 尝试使用getFragmentManager（）还是可以复制错误日志？