Myujth

I'm building an app that receives the input from EditText widgets, calculates and displays the results. I have built the xml draft but I am a begginer so I am a bit stuck on java...

Specifically I want help on making the resulted number appear rounded to 2 decimals.
When I enter the Decimal Format method, once I tap the "Calculate" Button, the app crashes.

Here's the code I wrote till now.

IMAGE of what the app looks like

package com.example.android.deyalcalculator;

EditText mEditX1a;
EditText mEditX1b;
EditText mEditX1c;

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

 Button CalculateButton = (Button) findViewById(R.id.calculateButton);
 mEditX1a = (EditText) findViewById(R.id.aTextX1);

 mEditX1b = (EditText) findViewById(R.id.bTextX1);

 mEditX1c = (EditText) findViewById(R.id.cTextX1);

 CalculateButton.setOnClickListener(new View.OnClickListener() 
 @Override
 public void onClick(View view) 
 String X1a = mEditX1a.getText().toString();
 double X1aInput = Double.parseDouble(X1a);

 String X1b = mEditX1b.getText().toString();
 double X1bInput = Double.parseDouble(X1b);

 String X1c = mEditX1c.getText().toString();
 double X1cInput = Double.parseDouble(X1c);

 Double dX1Result = ((X1bInput - X1aInput) / 25) * 1000;
 TextView dX1TextView = findViewById(R.id.dX1);
 String dX1StringDouble = Double.toString(dX1Result);
 dX1TextView.setText(dX1StringDouble);

 new DecimalFormat ("#.00").format(dX1StringDouble); //(Without this it works)
 

 );

}

The Error is this:

Process: com.example.android.deyalcalculator, PID: 12243
java.lang.NumberFormatException: empty String
 at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)
 at java.lang.Double.parseDouble(Double.java:547)
 at com.example.android.deyalcalculator.MainActivity$1.onClick(MainActivity.java:45)
 at android.view.View.performClick(View.java:5619)
 at android.view.View$PerformClick.run(View.java:22298)
 at android.os.Handler.handleCallback(Handler.java:754)
 at android.os.Handler.dispatchMessage(Handler.java:95)
 at android.os.Looper.loop(Looper.java:165)
 at android.app.ActivityThread.main(ActivityThread.java:6354)
 at java.lang.reflect.Method.invoke(Native Method)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:883)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)