我是Android的新手，并试图编写饮食计划安卓应用程序。 在第一部分中，我尝试计算BMI和理想体重以及每日卡路里，但是当我想要运行项目时，我会遇到致命错误，我不知道如何解决它。 谁能帮我？ 错误：
08-02 08:05:24.693: E/AndroidRuntime(1046): FATAL EXCEPTION: main
08-02 08:05:24.693: E/AndroidRuntime(1046): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dietandroidproject/com.dietandroidproject.MainActivity}: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.RadioGroup
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.ActivityThread.access$600(ActivityThread.java:130)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.os.Handler.dispatchMessage(Handler.java:99)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.os.Looper.loop(Looper.java:137)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.ActivityThread.main(ActivityThread.java:4745)
08-02 08:05:24.693: E/AndroidRuntime(1046): at java.lang.reflect.Method.invokeNative(Native Method)
08-02 08:05:24.693: E/AndroidRuntime(1046): at java.lang.reflect.Method.invoke(Method.java:511)
08-02 08:05:24.693: E/AndroidRuntime(1046): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
08-02 08:05:24.693: E/AndroidRuntime(1046): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-02 08:05:24.693: E/AndroidRuntime(1046): at dalvik.system.NativeStart.main(Native Method)
08-02 08:05:24.693: E/AndroidRuntime(1046): Caused by: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.RadioGroup
08-02 08:05:24.693: E/AndroidRuntime(1046): at com.dietandroidproject.MainActivity$1.<init>(MainActivity.java:30)
08-02 08:05:24.693: E/AndroidRuntime(1046): at com.dietandroidproject.MainActivity.onCreate(MainActivity.java:24)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.Activity.performCreate(Activity.java:5008)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
08-02 08:05:24.693: E/AndroidRuntime(1046): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
08-02 08:05:24.693: E/AndroidRuntime(1046): ... 11 more
MY MAIN ACTIVITY CODES
package com.dietandroidproject;
import Databasedata.Person;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioGroup;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button saveinformation = (Button) findViewById(R.id.saveinformation);
saveinformation.setOnClickListener(new View.OnClickListener() {
EditText weighttext = (EditText) findViewById(R.id.weighttext);
EditText heighttext = (EditText) findViewById(R.id.heighttext);
EditText usernametext = (EditText) findViewById(R.id.usernametext);
EditText agetext = (EditText) findViewById(R.id.agetext);
RadioGroup genderselected = (RadioGroup) findViewById(R.id.choosegender);
Spinner activitytext = (Spinner) findViewById(R.id.chooseactivity);
Button saveinformation = (Button) findViewById(R.id.saveinformation);
TextView genderchoosed = (TextView) findViewById(genderselected
.getCheckedRadioButtonId());
String gender = genderchoosed.getText().toString();
String pa = activitytext.getSelectedItem().toString();
@Override
public void onClick(View v) {
int weight = (int) Float.parseFloat(weighttext.getText()
.toString());
int height = (int) Float.parseFloat(heighttext.getText()
.toString());
String username = usernametext.getText().toString();
int age = (int) Float.parseFloat(agetext.getText().toString());
TextView genderchoosed = (TextView) findViewById(genderselected
.getCheckedRadioButtonId());
String gender = genderchoosed.getText().toString();
String pa = activitytext.getSelectedItem().toString();
//=========================================================
int Bmivalue = calculateBMI(weight, height);
String bmiInterpretation = interpretBMI(Bmivalue);
float idealweight = idealweight(weight, height, gender, pa, age);
double dailycalories=dailycalories(weight,height,gender,pa,age);
// insert in to============================================
Person person = new Person();
person.setUsername(username);
person.setHeight(height);
person.setWeight(weight);
person.setAge(age);
person.setGender(gender);
person.setPa(pa);
person.setBmivalue(Bmivalue);
person.setBmiInterpretation(bmiInterpretation);
person.setIdealweight(idealweight);
person.setDailycalories(dailycalories);
// ?????????????????????????????????????????/
Databasedata.DatabaseAdapter dbAdapter = new Databasedata.DatabaseAdapter(
MainActivity.this);
dbAdapter.insertPerson(person);
Toast.makeText(getApplicationContext(),
Bmivalue + "and you are" + bmiInterpretation,
Toast.LENGTH_LONG).show();
}
});
}
// BMI function==================================================
private int calculateBMI(int weight, int height) {
return (int) (weight / (height * height));
};
private String interpretBMI(int Bmivalue) {
if (Bmivalue < 18.5) {
return "Underweight";
} else if (Bmivalue < 25) {
return "Normal";
} else if (Bmivalue < 30) {
return "Overweight";
} else {
return "Obese";
}
}
//==========================IDEAL WEIGHT function======================
private float idealweight(int weight, int height, String gender, String pa,
int age) {
float x = (float) 0.0;
int bmi;
bmi = idealbmi(age);
x = bmi * (height * height);
return x;
}
public int idealbmi(int age) {
int bmi = 0;
if (age > 17 && age <= 19) {
bmi = 21;
}
if (age > 19 && age <= 24) {
bmi = 22;
}
if (age > 24 && age <= 34) {
bmi = 23;
}
if (age > 34 && age <= 44) {
bmi = 24;
}
if (age > 44 && age <= 54) {
bmi = 25;
}
if (age > 54 && age <= 64) {
bmi = 26;
}
if (age > 64) {
bmi = 27;
}
return bmi;
}
//======================DAILY CALORIES function ==============
public double suitablepa(String pa) {
double suitablepa = 0;
if (pa.equals("Highly active")) {
suitablepa = 1.48;
}
if (pa.equals("Active")) {
suitablepa = 1.25;
}
if (pa.equals("Low activity")) {
suitablepa = 1.11;
}
if (pa.equals("Sedentary")) {
suitablepa = 1;
}
return suitablepa;
}
private double dailycalories(int weight, int height, String gender,
String pa, int age) {
double dailycalori = 0;
double i;
double j;
double h;
double k;
if(gender.equals("femaleselected")){
i=9.36*weight;
j=726*height;
h=suitablepa(pa)*(i+j);
k=6.91*age;
dailycalori=354-k+h;
}else if(gender.equals("maleselected")){
i=15.91*weight;
j=539.6*height;
h=suitablepa(pa)*(i+j);
k=9.53*age;
dailycalori=662-k+h;
}
return dailycalori;
}
}
XML CODES
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/backgroundmain"
android:orientation="vertical" >
<RelativeLayout
android:id="@+id/personinformation"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1.98" >
<EditText
android:id="@+id/heighttext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/usernametext"
android:layout_below="@+id/usernametext"
android:ems="10"
android:hint="Enter Your Height" >
</EditText>
<EditText
android:id="@+id/usernametext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:ems="10"
android:hint="Enter Username" />
<EditText
android:id="@+id/weighttext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/heighttext"
android:layout_below="@+id/heighttext"
android:ems="10"
android:hint="Enter Your Weight" />
<EditText
android:id="@+id/agetext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/weighttext"
android:layout_below="@+id/weighttext"
android:ems="10"
android:hint="Enter Your Age" >
<requestFocus />
</EditText>
</RelativeLayout>
<View
android:layout_width="250dp"
android:layout_height="1dip"
android:layout_gravity="center"
android:layout_marginTop="20dp"
android:background="#aaa" />
<RelativeLayout
android:id="@+id/choosegender"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.78" >
<TextView
android:id="@+id/choosefemaleormale"
android:layout_width="match_parent"
android:layout_height="30dip"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="10dip"
android:gravity="center"
android:text="Gender : "
android:textAlignment="center"
android:textColor="#555"
android:textSize="19sp" />
<RadioGroup
android:layout_width="220dip"
android:layout_height="wrap_content"
android:layout_below="@+id/choosefemaleormale"
android:layout_centerHorizontal="true"
android:orientation="horizontal" >
<RadioButton
android:id="@+id/femaleselected"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:layout_weight="1"
android:checked="true"
android:text="female"
android:onClick="onRadioButtonClicked"
/>
<RadioButton
android:id="@+id/maleselected"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:layout_weight="1"
android:text="male"
android:onClick="onRadioButtonClicked" />
</RadioGroup>
</RelativeLayout>
<View
android:layout_width="250dp"
android:layout_height="1dip"
android:layout_gravity="center"
android:layout_marginTop="20dp"
android:background="#aaa" />
<RelativeLayout
android:id="@+id/choosepa"
android:layout_width="250dip"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_gravity="center" >
<Spinner
android:id="@+id/chooseactivity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:entries="@array/activityitems"
android:gravity="center"
android:prompt="@string/level_of_activity" />
</RelativeLayout>
<Button
android:layout_width="90dp"
android:layout_height="0dp"
android:layout_gravity="right"
android:layout_marginBottom="10dip"
android:layout_marginRight="20dp"
android:layout_weight="0.46"
android:background="@drawable/recent_foods_depressed"
android:hint="save"
android:text="save"
android:textColor="#fff"
android:textSize="20sp"
android:textStyle="bold"
android:onClick="saveinformation"
android:id="@+id/saveinformation"/>
</LinearLayout>
答案 0 :(得分：0)
java.lang.ClassCastException：android.widget.RelativeLayout无法强制转换为android.widget.RadioGroup
ChooseGender需要被强制转换为RelativeLayout。或者，如果您想要收音机组，请使用R.id.choosefemaleormale
答案 1 :(得分：0)
首先在choosegender RadioGroup中为您的RelativeLayout提供ID，然后按以下方式访问RadioGroup：
RadioGroup genderselected = (RadioGroup) findViewById(R.id.yourRadioGroupId);