android:onClick = "clickFun1"的 Button无法识别clickFun1()类中提到的DipToVol extends Fragment方法。 Android Studio表示该方法无处使用。
public class DipToVol extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_one, container, false);
}
public double calVol(short rad, short len, int height) {
double area;
area = (Math.PI * Math.pow(rad, 2) / 2) - Math.pow(rad, 2) * Math.asin(1 - (height / (double)rad)) - (rad - height) * Math.sqrt(height * (2 * rad - height));
return area*len*0.000001;
}
//here android studio says this method never used
public void clickFun1 (View view)
{
int dipHSD = 0, dipMS = 0;
final short radHSD = 1219;
final short lenHSD = 6810;
final short radMS = 999;
final short lenMS = 6804;
double volHSD, volMS;
EditText dipH = (EditText) view.findViewById(R.id.dipHSD1);
EditText dipM = (EditText) view.findViewById(R.id.dipMS1);
TextView volH = (TextView) view.findViewById(R.id.volHSD1);
TextView volM = (TextView) view.findViewById(R.id.volMS1);
try {
dipHSD = Integer.parseInt(dipH.getText().toString());
volHSD = calVol(radHSD, lenHSD, dipHSD);
volHSD = Math.round(volHSD);
volH.setText(volHSD + "");
}
catch (NumberFormatException e) {
volH.setText("");
}
try{ dipMS = Integer.parseInt(dipM.getText().toString());
volMS = calVol(radMS, lenMS, dipMS);
volMS = Math.round(volMS);
volM.setText(volMS + "");
}catch(NumberFormatException e){volM.setText("");}
}
//here android studio says this method never used
public void clearFun1(View view){
EditText dipH = (EditText) view.findViewById(R.id.dipHSD1);
EditText dipM = (EditText) view.findViewById(R.id.dipMS1);
TextView volH = (TextView) view.findViewById(R.id.volHSD1);
TextView volM = (TextView) view.findViewById(R.id.volMS1);
volH.setText("");
volM.setText("");
dipH.setText("");
dipM.setText("");
}
}
fragment_one.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/section_label1"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
android:background="#4ab4b2">
<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/contentView"
android:layout_weight ="1"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="false"
android:layout_alignParentRight="false"
android:layout_alignWithParentIfMissing="false">
<TableRow
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HSD Dip"
android:id="@+id/lableDipHSD"
android:layout_column="0"
android:textSize="30sp"
android:textStyle="bold"
android:textColor="#ffffff"
android:layout_marginLeft="5dp" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="number"
android:ems="10"
android:id="@+id/dipHSD1"
android:textSize="30sp"
android:textStyle="bold"
android:layout_column="1"
android:textColor="#ffffff"
/>
</TableRow>
<TableRow
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="MS Dip"
android:id="@+id/lableDipMS"
android:layout_column="0"
android:textSize="30sp"
android:textStyle="bold"
android:textColor="#ffffff"
android:layout_marginLeft="5dp" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="number"
android:id="@+id/dipMS1"
android:layout_column="1"
android:textStyle="bold"
android:textSize="30sp"
android:textColor="#ffffff"
/>
</TableRow>
<TableRow
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HSD Volume"
android:id="@+id/lableVolHSD"
android:layout_column="0"
android:textStyle="bold"
android:textSize="30sp"
android:paddingTop="15dp"
android:textColor="#ffffff"
android:layout_marginLeft="5dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/volHSD1"
android:layout_column="1"
android:textStyle="bold"
android:textSize="30sp"
android:textColor="#ffffff" />
</TableRow>
<TableRow
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="MS Volume"
android:id="@+id/lableVolMS"
android:layout_column="0"
android:textStyle="bold"
android:textSize="30sp"
android:paddingTop="15dp"
android:textColor="#ffffff"
android:layout_marginLeft="5dp"
android:paddingBottom="10dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/volMS1"
android:layout_column="1"
android:textStyle="bold"
android:textSize="30sp"
android:textColor="#ffffff"
android:paddingBottom="10dp" />
</TableRow>
</TableLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/clearBtn"
android:id="@+id/clearBtn1"
android:textSize="25sp"
android:clickable="true"
android:onClick="clearFun1"
android:background="#fa0690"
android:padding="8dp"
android:paddingLeft="8dp"
android:paddingTop="2dp"
android:paddingRight="8dp"
android:paddingBottom="2dp"
android:textAlignment="center"
android:textStyle="bold"
android:layout_column="0"
android:layout_below="@+id/contentView"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="40dp"
android:layout_toStartOf="@+id/calcBtn1"
android:layout_toLeftOf="@+id/calcBtn1"
android:alpha="0.8"
android:layout_marginRight="10dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/calcBtn"
android:id="@+id/calcBtn1"
android:textSize="25sp"
android:clickable="true"
android:onClick="clickFun1"
android:background="#fa0690"
android:padding="8dp"
android:paddingLeft="8dp"
android:paddingTop="2dp"
android:paddingRight="8dp"
android:paddingBottom="2dp"
android:textAlignment="center"
android:textStyle="bold"
android:layout_column="0"
android:layout_alignTop="@+id/clearBtn1"
android:layout_alignRight="@+id/contentView"
android:layout_alignEnd="@+id/contentView"
android:alpha="0.8" />
</RelativeLayout>
请告诉我我做错了什么。当我运行代码时，App正在崩溃。错误日志显示找不到clickFun1()。
// logcat
09-10 13:49:24.823 2718-2718/com.example.siv.mahalaxmipetroleums E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.IllegalStateException: Could not find method clickFun1(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'calcBtn'
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.resolveMethod(AppCompatViewInflater.java:327)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:284)
at android.view.View.performClick(View.java:4240)
at android.view.View$PerformClick.run(View.java:17721)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
我已更改mainActivity.java，如下所示。将代码从片段子类移动到mainActivity.java
package com.example.siv.mahalaxmipetroleums;
import android.support.design.widget.TabLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
Button clearBtn_f1,calcBtn_f1,clearBtn_f2,calcBtn_f2;
/**
* The {@link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
clearBtn_f1 = (Button) findViewById(R.id.clearBtn1);
clearBtn_f2 = (Button) findViewById(R.id.clearBtn2);
calcBtn_f1 = (Button) findViewById(R.id.calcBtn1);
calcBtn_f2 = (Button) findViewById(R.id.calcBtn2);
clearBtn_f1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
clearFun1(v);
}
});
clearBtn_f2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
clearFun2(v);
}
});
calcBtn_f1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
clickFun1(v);
}
});
calcBtn_f2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
clickFun2(v);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
// */
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
/* @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_one, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}*/
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
if (position == 0) {
return new Fragment_One();
} else if (position == 1) {
return new Fragment_Two();
} else
return new Fragment_Three();//PlaceholderFragment.newInstance(position + 1);
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "Dip-Vol";
case 1:
return "Vol-Dip";
case 2:
return "Temp-Dens";
}
return null;
}
}
public void clickFun1 (View view)
{
short dipHSD = 0, dipMS = 0;
final short radHSD = 1219;
final short lenHSD = 6810;
final short radMS = 999;
final short lenMS = 6804;
double volHSD, volMS;
EditText dipH = (EditText) view.findViewById(R.id.dipHSD1);
EditText dipM = (EditText) view.findViewById(R.id.dipMS1);
TextView volH = (TextView) view.findViewById(R.id.volHSD1);
TextView volM = (TextView) view.findViewById(R.id.volMS1);
try {
dipHSD = Short.parseShort(dipH.getText().toString());
Liquid_Volume dtvh = new Liquid_Volume(radHSD,lenHSD,dipHSD);
volHSD = dtvh.getVolume();
volHSD = Math.round(volHSD);
volH.setText(volHSD + "");
}
catch (NumberFormatException e) {
volH.setText("");
}
try{ dipMS = Short.parseShort(dipM.getText().toString());
Liquid_Volume dtvm = new Liquid_Volume(radMS,lenMS,dipMS);
volMS = dtvm.getVolume();
volM.setText(volMS + "");
}catch(NumberFormatException e){volM.setText("");}
}
public void clearFun1(View view){
EditText dipH = (EditText) view.findViewById(R.id.dipHSD1);
EditText dipM = (EditText) view.findViewById(R.id.dipMS1);
TextView volH = (TextView) view.findViewById(R.id.volHSD1);
TextView volM = (TextView) view.findViewById(R.id.volMS1);
volH.setText("");
volM.setText("");
dipH.setText("");
dipM.setText("");
}
public void clickFun2 (View view)
{
EditText volH = (EditText) view.findViewById(R.id.volHSD2);
EditText volM = (EditText) view.findViewById(R.id.volMS2);
TextView dipH = (TextView) view.findViewById(R.id.dipHSD2);
TextView dipM = (TextView) view.findViewById(R.id.dipMS2);
double volHSD = 0, volMS = 0;
final double radHSD = 121.9;
final double lenHSD = 681.0;
final double radMS = 99.9;
final double lenMS = 680.4;
double dipHSD, dipMS;
try {
volHSD = Double.parseDouble(volH.getText().toString());
Liquid_Height HSD = new Liquid_Height(radHSD,lenHSD,volHSD);
dipHSD = HSD.getDip();
//String.format("%f",dipHSD);
//dipH.setText(Double.toString(dipHSD));
dipH.setText(dipHSD + "");
}
catch (NumberFormatException e) {
dipH.setText("");
}
try{ volMS = Double.parseDouble(volM.getText().toString());
Liquid_Height MS = new Liquid_Height(radMS,lenMS,volMS);
dipMS = MS.getDip();
//String.format("%f",dipHSD);
//dipM.setText(String.format("%f",dipMS));
dipM.setText(dipMS + "");
}
catch(NumberFormatException e){
dipM.setText("");
}
}
public void clearFun2(View view){
EditText volH = (EditText) view.findViewById(R.id.volHSD2);
EditText volM = (EditText) view.findViewById(R.id.volMS2);
TextView dipH = (TextView) view.findViewById(R.id.dipHSD2);
TextView dipM = (TextView) view.findViewById(R.id.dipMS2);
volH.setText("");
volM.setText("");
dipH.setText("");
dipM.setText("");
}
}
然后我有了fragment_one.java并以同样的方式休息其他片段。
public class Fragment_One extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_one, container, false);
}
}
此处应用程序在我尝试打开后立即崩溃。
Logcat说以下
09-12 07:17:40.600 2283-2291/com.google.android.gms E/StrictMode: A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks.
java.lang.Throwable: Explicit termination method 'close' not called
at dalvik.system.CloseGuard.open(CloseGuard.java:184)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:190)
at ...
答案 0 :(得分：1)
这不是错误。 （方法警告，而不是应用程序崩溃）。 Java编译器不知道你已经在XML中定义了监听器，所以既然你从未明确地调用这些方法，它只是认为它们“从不使用”
就个人而言，我总是在Java代码
的视图上设置OnClickListener答案 1 :(得分：1)
当Android运行并检查onClick方法时，它只在主Activity类中查找。您无法在片段中放置onClick方法。碎片与活动不同，因此不应滥用它们。
另一个问题在这里有同样的问题：https://stackoverflow.com/a/39429157/6754053
答案 2 :(得分：0)
正如其他用户所说。您不能将onClick属性与Fragments一起使用。但这个宇宙拥有杰克沃顿和他令人敬畏的图书馆，包括Butterknife。 Check this out.
答案 3 :(得分：0)
从布局的根目录中删除此行可能会有所帮助;
tools:context=".MainActivity"