Question

I am trying to display the float value “degrees” as a string in a TextView on my layout, but receive a NullPointerException on tv.setText(mydegrees); I have tried numerous methods to convert the float to a usable string value, but can’t seem to get the TextView to display the float value. Any help would be greatly appreciated!

Note: The degrees is manipulated by an onTouchEvent

TextView from XML:

<TextView
android:id="@+id/current_degrees"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_vertical|center"
android:text="@string/app_name"
android:textColor="#FFFF00" />

Java Code:

float degrees = (float) -65;
String mydegrees = String.format("%.2f", degrees) ;

//...

public void pushClick(View pushClick) {
    switch (pushClick.getId()) {
    case R.id.btn_push:

        TextView tv = (TextView) findViewById(R.id.current_degrees);
        tv.setText(mydegrees);

Answer 1

Edit: As @Jake King noted, in my previous answer I was not paying attention to the details (that your mydegree member is a String instance.

This way the only reason for you to get a NPE is that your tv TextView is null.

Please check your layout xml file you use for the activity / renderer / view, and make sure you have there a TextView or any extension of it with @+id/current_degrees.

Also, your title is very misleading: If you have your float declared and initialized as above, then there cannot be any NullPointerException.