java - FragmentTransaction 类型中的方法 add(int, Fragment) 不适用于参数 (int, WeatherFragment)

Question

我的 fragment 有错误:

"The method replace(int, Fragment) in the type Fragment Transaction is not applicable for the arguments (int, Fragment)"

我该怎么办？我的 fragment 没有出现。

    package com.example.weather;

    import android.support.v7.app.ActionBarActivity;

    import android.support.v4.app.Fragment;

    import android.text.InputType;
    import android.app.AlertDialog;

    import android.content.DialogInterface;

    import android.os.Bundle;

    import android.view.LayoutInflater;

    import android.view.Menu;

    import android.view.MenuItem;

    import android.view.View;

    import android.view.ViewGroup;

    import android.widget.EditText;

    import android.os.Build;

    public class WeatherActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_weather);
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new WeatherFragment())
                    .commit();
        }
    }


    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(item.getItemId() == R.id.change_city){
            showInputDialog();
        }
        return false;
    }

    private void showInputDialog(){
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Change city");
        final EditText input = new EditText(this);
        input.setInputType(InputType.TYPE_CLASS_TEXT);
        builder.setView(input);
        builder.setPositiveButton("Go", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                changeCity(input.getText().toString());
            }
        });
        builder.show();
    }

    public void changeCity(String city){
        WeatherFragment wf = (WeatherFragment) getFragmentManager()
                .findFragmentById(R.id.container);
        wf.changeCity(city);
        new CityPreference(this).setCity(city);
    }
}

Answer 1

应该更改 fragment 的导入。 这是错误的:-

导入 android.support.v4.app.Fragment;

正确的导入是:-

导入 android.app.Fragment;