Java 无法添加函数";OnClickListener";到图像按钮
以下是我的Java代码:Java 无法添加函数";OnClickListener";到图像按钮,java,android,android-imagebutton,Java,Android,Android Imagebutton,以下是我的Java代码: public class MainPage extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener { TabLayout tabLayout; ViewPageAdapter viewPageAdapter; ViewPager viewPager; ImageButton pfp; Bitmap bitmap_one; private String
public class MainPage extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
TabLayout tabLayout;
ViewPageAdapter viewPageAdapter;
ViewPager viewPager;
ImageButton pfp;
Bitmap bitmap_one;
private String UPLOAD_URL = "http://.php";
private int PICK_IMAGE_REQUEST = 1;
private String KEY_IMAGE = "image";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_page);
initTypeface();
//id's
pfp = (ImageButton) findViewById(R.id.imageButton_one);
pfp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (v == pfp){
showFileChooser();
}
}
});
//SearchIntent
Intent searchI = getIntent();
if (Intent.ACTION_SEARCH.equals(searchI.getAction())) {
String query = searchI.getStringExtra(SearchManager.QUERY);
Toast.makeText(MainPage.this, query, Toast.LENGTH_SHORT).show();
}
//Toolbar
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle(null);
//Tabs
tabLayout = (TabLayout) findViewById(R.id.tablayout_two);
viewPager = (ViewPager) findViewById(R.id.viewPager_two);
viewPageAdapter = new ViewPageAdapter(getSupportFragmentManager());
viewPageAdapter.addFragments(new FeedFragment(), "Feed");
viewPageAdapter.addFragments(new MessagesFragment(), "Messages");
viewPageAdapter.addFragments(new NotificationsFragment(), "Notifications");
viewPager.setAdapter(viewPageAdapter);
tabLayout.setupWithViewPager(viewPager);
//FloatingActionButton
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
}
});
//NavigationDrawer
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 = (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 onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.profile) {
Intent i = new Intent(this, Profile.class);
startActivity(i);
} else if (id == R.id.whatshot) {
Intent i = new Intent(this, WhatsHot.class);
startActivity(i);
} else if (id == R.id.trending) {
Intent i = new Intent(this, Trending.class);
startActivity(i);
} else if (id == R.id.radioplayer) {
Intent i = new Intent(this, Radio.class);
startActivity(i);
} else if (id == R.id.musicplayer) {
Intent i = new Intent(this, MusicPlayer.class);
startActivity(i);
} else if (id == R.id.settings) {
Intent i = new Intent(this, Settings.class);
startActivity(i);
} else if (id == R.id.info) {
Intent i = new Intent(this, Info.class);
startActivity(i);
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_menu, menu);
SearchView searchView = (SearchView) menu.findItem(R.id.search_view).getActionView();
SearchManager searchManager = (SearchManager) getSystemService(SEARCH_SERVICE);
searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
return super.onCreateOptionsMenu(menu);
}
//ImageInfo
private void showFileChooser() {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) {
Uri filePath = data.getData();
try {
bitmap_one = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
pfp.setImageBitmap(bitmap_one);
} catch (IOException e) {
e.printStackTrace();
}
}
}
//Typeface
private void initTypeface() {
Typeface myTypeface = Typeface.createFromAsset(getAssets(), "fonts/Amble-Regular.ttf");
TextView text = (TextView) findViewById(R.id.toolbarTitle);
text.setTypeface(myTypeface);
}
}
以下是我的XML代码:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="@dimen/nav_header_height"
android:background="@drawable/side_nav_bar"
android:gravity="bottom"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:theme="@style/ThemeOverlay.AppCompat.Dark">
<ImageButton
android:id="@+id/imageButton_one"
android:layout_width="90dp"
android:background="#2A363B"
android:onClick="pfpClick"
android:layout_height="90dp"
android:paddingTop="@dimen/nav_header_vertical_spacing" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="@dimen/nav_header_vertical_spacing"
android:text=""
android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="" />
</LinearLayout>
我试图实现的是,只要单击ImageButton,我就可以选择一个文件并添加它。但我不断地得到一个错误:
尝试调用虚拟方法“void”
android.widget.ImageButton.setOnClickListener(android.view.view$OnClickListener)'
关于空对象引用
p.S“我的图像”按钮位于导航抽屉中。您应该执行以下操作之一:
android:onClick="pfpClick"
但是您需要在类中定义一个名为pfpClick的方法,而该方法不存在
还是这个
pfp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (v == pfp){
showFileChooser();
}
}
});
两者同时进行是一种不好的做法,对于第二种选择来说也是如此
这是不必要的:
if (v == pfp){
因为您正在实现的侦听器是匿名的
我建议在布局中删除此选项:
android:onClick="pfpClick"
然后清理/修改侦听器代码段:
pfp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showFileChooser();
}
});
您应该执行以下操作之一:
android:onClick="pfpClick"
但是您需要在类中定义一个名为pfpClick的方法,而该方法不存在
还是这个
pfp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (v == pfp){
showFileChooser();
}
}
});
两者同时进行是一种不好的做法,对于第二种选择来说也是如此
这是不必要的:
if (v == pfp){
因为您正在实现的侦听器是匿名的
我建议在布局中删除此选项:
android:onClick="pfpClick"
然后清理/修改侦听器代码段:
pfp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showFileChooser();
}
});
看起来像是行
pfp=(ImageButton)findViewById(R.id.ImageButton\u one)代码>返回一个空对象
只有当您的XML出现问题时(您没有使用正确的布局,或者视图id
与XML中的视图不匹配),这才符合逻辑
另一种情况可能是,您必须执行Build->cleanproject
,然后重新构建并运行应用程序。看起来像pfp=(ImageButton)findViewById(R.id.ImageButton\u one)这一行代码>返回一个空对象
只有当您的XML出现问题时(您没有使用正确的布局,或者视图id
与XML中的视图不匹配),这才符合逻辑
另一种情况可能是,您必须执行Build->Clean Project
,然后重新生成并运行您的应用程序。您是否尝试过清理并重新生成您的项目?如果您真的想执行一个条件,那么它应该像if(v.getId()==R.id.imageButton_one),而不是if(v==pfp)。是否尝试清理和重建项目?如果确实要执行某个条件,则应该是if(v.getId()==R.id.imageButton_one),而不是if(v==pfp)。