Databases
StackOverflow2013
Postsdbo
POAndroid button call another function
Body
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POAndroid button call another function
    text
    copied!<p>I try to use my Android button to change the value of at_command </p> <p>If I call <code>"intOfFloat(float f)"</code> in <code>btnLeftListener</code> the logcat will show</p> <pre><code>01-23 16:17:28.610: E/AndroidRuntime(1154): java.lang.NullPointerException </code></pre> <p>please help me solve this:)</p> <pre><code>String at_cmd = ""; FloatBuffer fb; IntBuffer ib; int PORT=5556; float speed = (float)0.1; int seq = 1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); btnLeft=(Button)findViewById(R.id.LeftBtn); btnLeft.setOnClickListener(btnLeftListener); } public Button.OnClickListener btnLeftListener= new Button.OnClickListener(){ @Override public void onClick(View arg0) { at_cmd = "AT*PCMD=" + (seq++) + ",1," + intOfFloat(-speed)+",0,0,0"; } }; public int intOfFloat(float f) { fb.put(0, f); return ib.get(0); } </code></pre> <p>logcat</p> <pre><code>01-23 16:17:28.591: W/dalvikvm(1154): threadid=1: thread exiting with uncaught exception (group=0x40a13300) 01-23 16:17:28.610: E/AndroidRuntime(1154): FATAL EXCEPTION: main 01-23 16:17:28.610: E/AndroidRuntime(1154): java.lang.NullPointerException 01-23 16:17:28.610: E/AndroidRuntime(1154): at com.example.dronedivideandroid.DroneMain.intOfFloat(DroneMain.java:60) 01-23 16:17:28.610: E/AndroidRuntime(1154): at com.example.dronedivideandroid.DroneMain$1.onClick(DroneMain.java:70) 01-23 16:17:28.610: E/AndroidRuntime(1154): at android.view.View.performClick(View.java:4084) 01-23 16:17:28.610: E/AndroidRuntime(1154): at android.view.View$PerformClick.run(View.java:16966) 01-23 16:17:28.610: E/AndroidRuntime(1154): at android.os.Handler.handleCallback(Handler.java:615) 01-23 16:17:28.610: E/AndroidRuntime(1154): at android.os.Handler.dispatchMessage(Handler.java:92) 01-23 16:17:28.610: E/AndroidRuntime(1154): at android.os.Looper.loop(Looper.java:137) 01-23 16:17:28.610: E/AndroidRuntime(1154): at android.app.ActivityThread.main(ActivityThread.java:4745) 01-23 16:17:28.610: E/AndroidRuntime(1154): at java.lang.reflect.Method.invokeNative(Native Method) 01-23 16:17:28.610: E/AndroidRuntime(1154): at java.lang.reflect.Method.invoke(Method.java:511) 01-23 16:17:28.610: E/AndroidRuntime(1154): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 01-23 16:17:28.610: E/AndroidRuntime(1154): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 01-23 16:17:28.610: E/AndroidRuntime(1154): at dalvik.system.NativeStart.main(Native Method) 01-23 16:17:28.631: W/ActivityManager(163): Force finishing activity com.example.dronedivideandroid/.DroneMain 01-23 16:17:28.641: W/WindowManager(163): Failure taking screenshot for (246x410) to layer 21010 01-23 16:17:29.150: W/ActivityManager(163): Activity pause timeout for ActivityRecord{4154a830 com.example.dronedivideandroid/.DroneMain} 01-23 16:17:29.351: I/Choreographer(262): Skipped 37 frames! The application may be doing too much work on its main thread. 01-23 16:17:30.591: I/Process(1154): Sending signal. PID: 1154 SIG: 9 01-23 16:17:30.601: I/ActivityManager(163): Process com.example.dronedivideandroid (pid 1154) has died. 01-23 16:17:30.601: I/WindowState(163): WIN DEATH: Window{414043e0 com.example.dronedivideandroid/com.example.dronedivideandroid.DroneMain paused=false} 01-23 16:17:30.691: W/InputMethodManagerService(163): Got RemoteException sending setActive(false) notification to pid 1154 uid 10047 01-23 16:17:40.091: W/ActivityManager(163): Activity destroy timeout for ActivityRecord{4154a830 com.example.dronedivideandroid/.DroneMain} 01-23 16:19:52.800: D/dalvikvm(248): GC_CONCURRENT freed 383K, 7% free 8537K/9095K, paused 6ms+5ms, total 46ms 01-23 16:23:49.971: E/ThrottleService(163): problem during onPollAlarm: java.lang.IllegalStateException: problem parsing stats: java.io.FileNotFoundException: /proc/net/xt_qtaguid/iface_stat_all: open failed: ENOENT (No such file or directory) 01-23 16:27:27.310: D/dalvikvm(248): GC_CONCURRENT freed 384K, 7% free 8537K/9095K, paused 17ms+6ms, total 56ms </code></pre>
 

Querying!

 
Guidance
An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload