Question

This is a follow up to the question I asked earlier. Basically I have a game where the main action happens on a canvas which is in a custom class extended from View.

I have the score saved in a String and I am trying to draw it to the top left corner of the screen.

At the bottom of my onDraw() method, I have the following line of code :

canvas.drawText(score, 5, 5, null); 

When I try to run the game, log cat gives me the following errors :

03-02 22:30:29.955: ERROR/AndroidRuntime(8140): FATAL EXCEPTION: main
03-02 22:30:29.955: ERROR/AndroidRuntime(8140): java.lang.NullPointerException
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.graphics.Canvas.drawText(Native Method)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at com.mattdrewery.supercatch.GameView.onDraw(GameView.java:143)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.View.draw(View.java:6880)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewGroup.drawChild(ViewGroup.java:1646)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.View.draw(View.java:6883)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.widget.FrameLayout.draw(FrameLayout.java:357)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewGroup.drawChild(ViewGroup.java:1646)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewGroup.drawChild(ViewGroup.java:1644)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.View.draw(View.java:6883)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.widget.FrameLayout.draw(FrameLayout.java:357)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1862)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewRoot.draw(ViewRoot.java:1522)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewRoot.performTraversals(ViewRoot.java:1258)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.os.Looper.loop(Looper.java:123)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at android.app.ActivityThread.main(ActivityThread.java:3683)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at java.lang.reflect.Method.invokeNative(Native Method)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at java.lang.reflect.Method.invoke(Method.java:507)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-02 22:30:29.955: ERROR/AndroidRuntime(8140):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

Your Paint parameter can’t be null.

Initialize it somewhere (not in onDraw);

Paint mPaint = new Paint();

canvas.drawText(score, 5, 5, mPaint);