Question

如何访问片段上的按钮和程序点击事件。我知道有类似的问题，但我已经尝试了他们提供的解决方案，但它们对我不起作用。我总是得到无法访问的错误。

要求;基本上我在XML中有两个按钮，一个是可见的，另一个则不是。我试图点击可见按钮，使其不可见，然后使之前不可见的按钮可见。

请注意，片段是通过编辑Android Studios默认的navaigation抽屉活动来制作的我正在尝试使用通用导航抽屉。更容易编辑默认类。

活动代码

package co.timetrax.drawer;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;

import butterknife.Bind;
import butterknife.ButterKnife;

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    NavigationView navigationView = null;
    Toolbar toolbar = null;

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

        //setting fragments
        MainFragment fragment = new MainFragment();
        android.support.v4.app.FragmentTransaction fragmentTransaction =
                getSupportFragmentManager().beginTransaction();
        fragmentTransaction.replace(R.id.fragment_container, fragment);
        fragmentTransaction.commit();

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == R.id.nav_camera) {
            // Handle the camera action
            MainFragment fragment = new MainFragment();
            android.support.v4.app.FragmentTransaction fragmentTransaction =
                    getSupportFragmentManager().beginTransaction();
            fragmentTransaction.replace(R.id.fragment_container, fragment);
            fragmentTransaction.commit();
        } else if (id == R.id.nav_gallery) {

        } else if (id == R.id.nav_slideshow) {

        } else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {

        } else if (id == R.id.nav_send) {

        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

片段代码

package co.timetrax.drawer;


import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import butterknife.Bind;
import butterknife.ButterKnife;



/**
 * A simple {@link Fragment} subclass.
 */
public class MainFragment extends Fragment implements View.OnClickListener {

    public MainFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_main, container, false);

    }

    @Override
    public void onClick(View v) {

    }

}

这是片段xml;

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="co.timetrax.drawer.MainFragment">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="MAIN"
        android:padding="8dp"
        android:textColor="#fff"
        android:background="@color/colorPrimary"
        android:textSize="28sp"
        android:id="@+id/main_button"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="second"
        android:visibility="gone"
        android:padding="8dp"
        android:textColor="#fff"
        android:background="@color/colorPrimary"
        android:textSize="28sp"
        android:id="@+id/second_button"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" />


</RelativeLayout>

Answer 1

将此方法更改为：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_main, container, false);
    Button mainButton = (Button) view.findViewById(R.id.main_button);
    //proceed to add the listener in a regular way
    //I will not write that code here; mainButton.setOnClickListener ......
    return view;

}

为每个Button或您需要的任何其他UI元素执行此操作。

Answer 2

您可以在片段中的任何位置调用getView()以获取根视图。然后你可以打电话：

View root = getView();
Button myButton = (Button) root.findViewById(R.id./*id*/);
myButton.setVisibility(View.INVISIBLE);

如何访问片段上的Button？

2 个答案: