Java （Android）试图理解为什么我的方法无法在textview中计算/显示正确的值

我的活动中称为（计算BMI）的方法应该计算和显示BMI（基于代码中的公式），并在textview中显示其值。应用程序运行正常，但显示的值始终为零。我正在努力找出问题是否出在我的公式中（不太可能），或者我传递值的方式是否不正确。任何帮助都将不胜感激。代码如下

.Java文件

import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;
import android.widget.TextView;
import android.view.View;
import android.widget.Toast;


public class Health extends ActionBarActivity {
    EditText bloodPressure;
    EditText cholesterol;
    int weight;
    int height;
    EditText heightString;
    EditText age;
    TextView bmiText;
    EditText weightString;
    MyDBHandler dbHandler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_health);
        weightString = (EditText) findViewById(R.id.weightTextBox);

        heightString =(EditText) findViewById(R.id.heightTextBox);

        bmiText = (TextView) findViewById(R.id.bmiTextView);
        bloodPressure = (EditText) findViewById(R.id.bloodPressureTextBox);
        cholesterol = (EditText) findViewById(R.id.cholesterolTextBox);
        age = (EditText) findViewById(R.id.ageTextBox);
        dbHandler = new MyDBHandler(this, null, null, 1);
    }

    public void calculateBMI(View view)
    {
        weight = Integer.parseInt(weightString.getText().toString());
        height = Integer.parseInt(heightString.getText().toString());
        int BMI = 703 * (weight/(height*height));
        bmiText.setText("Your calculated BMI is: " + Integer.toString(BMI));
        Toast.makeText(Health.this, " Info Saved ", Toast.LENGTH_SHORT).show();
        HealthInfo healthInfo = new HealthInfo(bloodPressure.getText().toString(),cholesterol.getText().toString(),heightString.getText().toString(),weightString.getText().toString(),age.getText().toString());
        dbHandler.addHealth(healthInfo);

    }

    public void calorieClick(View view){
        Intent i = new Intent(this, CalorieTracker.class);
        startActivity(i);
    }

    public void openTips(View view){
        Intent i = new Intent(this, HealthTipsActivity.class);
        startActivity(i);
    }

    public void openPlans(View view){
        Intent i = new Intent(this, DietPlansActivity.class);
        startActivity(i);
    }


    @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_health, 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);
    }
}

.XML文件

<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" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="seniorproject.broncos.broncowellnessapp.Health"
    android:background="#006699">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/blood_pressure_text"
        android:id="@+id/bloodPressureTextView"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/cholesterol_text"
        android:id="@+id/cholesterolTextView"
        android:layout_below="@+id/bloodPressureTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="35dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/weight_text"
        android:id="@+id/weightTextView"
        android:layout_below="@+id/cholesterolTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="35dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/height_text"
        android:id="@+id/heightTextView"
        android:layout_below="@+id/weightTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="35dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/age_text"
        android:id="@+id/ageTextView"
        android:layout_below="@+id/heightTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="35dp" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="text"
        android:ems="10"
        android:width="150dp"
        android:id="@+id/bloodPressureTextBox"
        android:layout_below="@+id/bloodPressureTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:ems="10"
        android:width="150dp"
        android:id="@+id/cholesterolTextBox"
        android:layout_below="@+id/cholesterolTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:ems="10"
        android:width="150dp"
        android:id="@+id/weightTextBox"
        android:layout_below="@+id/weightTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:ems="10"
        android:width="150dp"
        android:id="@+id/heightTextBox"
        android:layout_below="@+id/heightTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:ems="10"
        android:width="150dp"
        android:id="@+id/ageTextBox"
        android:layout_below="@+id/ageTextView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/diet_plans_button_text"
        android:onClick="openPlans"
        android:id="@+id/dietPlansButton"
        android:layout_below="@+id/ageTextBox"
        android:layout_marginTop="40dp"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/calorie_tracker_button"
        android:id="@+id/calorieAccessButton"
        android:layout_below="@+id/dietPlansButton"
        android:onClick ="calorieClick"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/tips_button_text"
        android:id="@+id/tipsButton"
        android:onClick="openTips"
        android:layout_below="@+id/calorieAccessButton"
        android:layout_alignRight="@+id/calorieAccessButton"
        android:layout_alignEnd="@+id/calorieAccessButton" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/BMI_button_text"
        android:id="@+id/bmiButton"
        android:onClick="calculateBMI"
        android:layout_alignBottom="@+id/cholesterolTextBox"
        android:layout_alignRight="@+id/dietPlansButton"
        android:layout_alignEnd="@+id/dietPlansButton"
        android:layout_marginRight="36dp"
        android:layout_marginEnd="36dp"
        android:background="#ff00b812" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:text="Push Button to Compute BMI"
        android:id="@+id/bmiTextView"
        android:layout_alignBottom="@+id/weightTextBox"
        android:layout_alignLeft="@+id/bmiButton"
        android:layout_alignStart="@+id/bmiButton" />
</RelativeLayout>

---

您的

体重

和

身高

变量是

int

。这是你的问题。将其更改为

float

或

double

---

当前，您正在进行整数除法，这会导致结果被截断，如下所示：

1/2

给出

0

您正在对整数进行除法，结果大部分为零。 这就是为什么结果总是零

将体重和身高变量更改为双倍，如下所示 然后将结果转换回int

double weight = 0.0;
double height = 0.0;

int BMI = (int)(703 * (weight/(height*height)));
bmiText.setText("Your calculated BMI is: " + Integer.toString(BMI));

---

将其放在onCreate（）方法的末尾：

某些android版本不支持XAML中按钮标记的onClick属性

findViewById(R.id.bmiButton).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            weight = Integer.parseInt(weightString.getText().toString());
            height = Integer.parseInt(heightString.getText().toString());
            int BMI = 703 * (weight/(height*height));
            bmiText.setText("Your calculated BMI is: " + Integer.toString(BMI));
            Toast.makeText(Health.this, " Info Saved ", Toast.LENGTH_SHORT).show();
            HealthInfo healthInfo = new HealthInfo(bloodPressure.getText().toString(),cholesterol.getText().toString(),heightString.getText().toString(),weightString.getText().toString(),age.getText().toString());
            dbHandler.addHealth(healthInfo);
        }
});