长度转换器android工作室

Question

我正在尝试制作一个长度转换器应用程序，我的困惑是如何使用两个微调器和一个计算按钮完成从一个单元转换到另一个单元的工作？我遇到的问题是我无法弄清楚如何将下拉列表中的单位从一个微调器转换为第二个微调器中的另一个单元。我还需要在用户输入号码后显示答案，然后从列表中选择单位。

这是我的主要活动的布局文件

 <?xml version="1.0" encoding="utf-8"?>
   <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.unitconverter.MainActivity">

<Button
    android:text="WEIGHT"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:onClick=""
    android:layout_below="@+id/lengthButton"
    android:layout_alignRight="@+id/lengthButton"
    android:layout_alignEnd="@+id/lengthButton"
    android:id="@+id/weightButton"
    tools:ignore="HardcodedText" />

<Button
    android:text="LENGTH"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lengthButton"
    android:layout_marginTop="164dp"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    tools:ignore="HardcodedText" />

<TextView
    android:text="Unit Converter"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="76dp"
    android:id="@+id/textView"
    android:textSize="36sp"
    android:textColor="@android:color/background_dark"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

<Button
    android:text="VOLUME"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/volumeButton"
    tools:ignore="HardcodedText"
    android:layout_below="@+id/weightButton"
    android:layout_alignLeft="@+id/weightButton"
    android:layout_alignStart="@+id/weightButton" />

<Button
    android:text="TEMPERATURE"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/temperatureButton"
    tools:ignore="HardcodedText"
    android:layout_below="@+id/volumeButton"
    android:layout_centerHorizontal="true" />

这是我主要活动的java部分

         public class MainActivity extends AppCompatActivity {

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



        Button lengthbtn = (Button) findViewById(R.id.lengthButton);

        lengthbtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v){
                startActivity(new Intent(MainActivity.this, lengthActivity.class));
            }
        });

        Button weightbtn = (Button) findViewById(R.id.weightButton);

        weightbtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v){
                startActivity(new Intent(MainActivity.this, weightActivity.class));
            }
        });

        Button volumebtn = (Button) findViewById(R.id.volumeButton);

        volumebtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v){
               startActivity(new Intent(MainActivity.this,volumeActivity.class));
            }
        });

        Button temperaturebtn = (Button) findViewById(R.id.temperatureButton);

        temperaturebtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v){
                startActivity(new Intent(MainActivity.this,temperatureActivity.class));
            }
        });

    }
}

这是我的长度布局文件

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_length"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.unitconverter.lengthActivity">

<Spinner
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dp"
    android:id="@+id/lengthList2"
    android:textAlignment="center"
    android:layout_marginLeft="11dp"
    android:layout_marginStart="11dp"
    android:layout_below="@+id/convertToTextView"
    android:layout_alignLeft="@+id/convertToTextView"
    android:layout_alignStart="@+id/convertToTextView" />

<TextView
    android:text="Length Converter"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="@style/TextAppearance.AppCompat.Display2"
    android:textSize="36sp"
    android:textAlignment="inherit"
    android:id="@+id/lengthTextView"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginLeft="25dp"
    android:layout_marginStart="25dp" />

<Button
    android:text="Calculate"
    android:id="@+id/calculateButton"
    android:layout_width="100dp"
    android:layout_height="45dp"
    android:layout_marginTop="53dp"
    android:layout_below="@+id/lengthList2"
    android:layout_alignRight="@+id/lengthList2"
    android:layout_alignEnd="@+id/lengthList2"
    android:layout_marginRight="23dp"
    android:layout_marginEnd="23dp"
    android:textAlignment="center" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/resultTextView"
    android:text="Result "
    android:textSize="20sp"
    android:layout_marginBottom="34dp"
    android:layout_alignParentBottom="true"
    android:layout_alignLeft="@+id/lengthList2"
    android:layout_alignStart="@+id/lengthList2" />

<TextView
    android:text="Convert to:"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="24sp"
    android:layout_marginTop="114dp"
    android:id="@+id/convertToTextView"
    android:layout_below="@+id/convertEditText"
    android:layout_alignLeft="@+id/convertEditText"
    android:layout_alignStart="@+id/convertEditText" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="textPersonName"
    android:text="Convert from"
    android:ems="10"
    android:id="@+id/convertEditText"
    android:layout_below="@+id/lengthTextView"
    android:layout_alignLeft="@+id/lengthTextView"
    android:layout_alignStart="@+id/lengthTextView"
    android:layout_marginLeft="11dp"
    android:layout_marginStart="11dp"
    android:layout_marginTop="52dp" />

<Spinner
    android:layout_height="wrap_content"
    android:entries="@array/lengthList"
    android:id="@+id/lengthList"
    android:layout_width="200dp"
    android:layout_marginTop="13dp"
    android:layout_below="@+id/convertEditText"
    android:layout_centerHorizontal="true" />

这是我的主要活动长度文件。有人可以帮帮我吗？

public class lengthActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate (saved Instance State);
        setContentView(R.layout.activity_length);

        final Spinner group = (Spinner)findViewById(R.id.lengthList);
        final Spinner group2 = (Spinner)findViewById(R.id.lengthList2);

        Button button = (Button)findViewById(R.id.calculateButton);

        button.setOnClickListener(new View.OnClickListener() {
            final TextView result = ((TextView) 



            @Override
            public void onClick(View v) {



            }

Answer 1

你好我已经创建了一个长度转换器..我希望它有所帮助

//java file

public class LengthConverter{

EditText val;
TextView ans, ftv;
Spinner from, to;
Integer positionFrom, positionTO, res;
Button convert;

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

    val = (EditText)findViewById(R.id.editText2);

    ans = (TextView)findViewById(R.id.Answer);

    from = (Spinner)findViewById(R.id.SpinnerFrom);
    to = (Spinner)findViewById(R.id.SpinnerTo);

    convert = (Button)findViewById(R.id.convert);


//        positionFrom = from.getSelectedItemPosition();
//        positionTO = to.getSelectedItemPosition();


    List<String> unitlength = new ArrayList<String>();

    unitlength.add("Meter");
    unitlength.add("Centimeter");
    unitlength.add("Kilometer");
    unitlength.add("Miles");
    unitlength.add("Foot");
    unitlength.add("Inches");
    unitlength.add("Yard");

    ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, unitlength);
    dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    from.setAdapter(dataAdapter);

    ArrayAdapter<String> unit = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, unitlength);
    unit.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    to.setAdapter(unit);

    from.setOnItemSelectedListener(this);

    to.setOnItemSelectedListener(this);


    convert.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            method(v);
        }
    });
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    parent.getItemAtPosition(position);

    switch (parent.getId())
    {
        case R.id.SpinnerFrom:
            from.setSelection(position);
            positionFrom = from.getSelectedItemPosition();
            Log.e("from selected position:", String.valueOf(positionFrom));
            break;

        case R.id.SpinnerTo:
            to.setSelection(position);
            positionTO = to.getSelectedItemPosition();
            Log.e("to selected position:", String.valueOf(positionTO));
            break;
    }

}


@Override
public void onNothingSelected(AdapterView<?> parent) {

}

public void method(View view)
{

     double value =  Double.parseDouble(val.getText().toString());
     double res;
     double hun = 100;

    Log.e("from value in method", String.valueOf(positionFrom));

    if (positionFrom == 0)
    {
        if (positionTO == 0)
        {
            val.setText("");
            ans.setText("");
        }

        if (positionTO == 1)
        {
            res = value * hun;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 2)
        {
            res = value * 1000;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 3)
        {
            res = value * 0.000621371;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 4)
        {
            res = value * 3.28084;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 5)
        {
            res = value * 39.3701;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 6)
        {
            res = value * 1.09361;
            ans.setText(Double.toString(res));
        }
    }

    if (positionFrom == 1)
    {
        if (positionTO == 0)
        {
            res = value / 100;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 1)
        {
            val.setText("");
            ans.setText("");
        }

        if (positionTO == 2)
        {
            res = value / 10000;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 3)
        {
            res = value * 6.2137e-6;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 4)
        {
            res = value * 0.0328084;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 5)
        {
            res = value * 0.393701;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 6)
        {
            res = value * 0.0109361;
            ans.setText(Double.toString(res));
        }
    }

    if ( positionFrom == 2)
    {
        if (positionTO == 0)
        {
            res = value * 1000;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 1)
        {
            res = value * 100000;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 2)
        {
            val.setText("");
            ans.setText("");
        }

        if (positionTO == 3)
        {
            res = value * 0.621371;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 4)
        {
            res = value * 3280.84;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 5)
        {
            res = value * 39370.1;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 6)
        {
            res = value * 1093.61;
            ans.setText(Double.toString(res));
        }
    }

    if (positionFrom == 3)
    {
        if (positionTO == 0)
        {
            res = value * 1609.34;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 1)
        {
            res = value * 160934;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 2)
        {
            res = value * 1.60934;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 3)
        {
            val.setText("");
            ans.setText("");
        }

        if (positionTO == 4)
        {
            res = value * 5280;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 5)
        {
            res = value * 63360 ;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 6)
        {
            res = value * 1760;
            ans.setText(Double.toString(res));
        }
    }

    if (positionFrom == 4)
    {
        if (positionTO == 0)
        {
            res = value * 0.3048;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 1)
        {
            res = value * 30.48;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 2)
        {
            res = value * 0.0003048;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 3)
        {

            res = value * 0.000189394;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 4)
        {
            val.setText("");
            ans.setText("");
        }

        if (positionTO == 5)
        {
            res = value * 12 ;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 6)
        {
            res = value * 0.333333;
            ans.setText(Double.toString(res));
        }
    }

    if (positionFrom == 5)
    {
        if (positionTO == 0)
        {
            res = value * 0.0254;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 1)
        {
            res = value * 2.54;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 2)
        {
            res = value * 2.54e-5;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 3)
        {
            res = value * 1.5783e-5;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 4)
        {
            res = value * 0.0833333 ;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 5)
        {
            val.setText("");
            ans.setText("");

        }

        if (positionTO == 6)
        {
            res = value * 0.0277778;
            ans.setText(Double.toString(res));
        }
    }

    if (positionFrom == 6)
    {
        if (positionTO == 0)
        {
            res = value * 0.9144;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 1)
        {
            res = value * 91.44;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 2)
        {
            res = value * 0.0009144;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 3)
        {

            res = value * 0.000568182;
            ans.setText(Double.toString(res));

        }

        if (positionTO == 4)
        {
            res = value * 3;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 5)
        {
            res = value * 36 ;
            ans.setText(Double.toString(res));
        }

        if (positionTO == 6)
        {
            val.setText("");
            ans.setText("");

        }
    }

}

}