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我剛剛創建返回結果給主機活動的機器人對話框按照此鏈接中的教程（在我的項目，它的mainActivity）處理你想要在對話框中做的事件，你應該在對話框類中使用接口。然後，在主機活動中，您應該實現此接口及其方法。但我注意到，只有在點擊正面按鈕時它纔會崩潰。這裏是我的代碼：Android的對話碰撞正面點擊
public class dialogFragement extends DialogFragment {
public interface NoticeDialogListener {
public void onDialogPositiveClick(DialogFragment dialog);
public void onDialogNegativeClick(DialogFragment dialog);
}
NoticeDialogListener mListener;
@Override
public void onAttach(Activity activity) {
// TODO Auto-generated method stub
super.onAttach(activity);
try {
// Instantiate the NoticeDialogListener so we can send events to the host
mListener = (NoticeDialogListener) activity;
} catch (ClassCastException e) {
// The activity doesn't implement the interface, throw exception
throw new ClassCastException(activity.toString()
+ " must implement NoticeDialogListener");
}
}
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
builder.setView(inflater.inflate(R.layout.dialog_layout, null))
// Add action buttons
.setPositiveButton("Onayla", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
mListener.onDialogPositiveClick(dialogFragement.this);
}
})
.setNegativeButton("İptal et", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
mListener.onDialogNegativeClick(dialogFragement.this);
}
});
return builder.create();
}
}
：
public void onDialogPositiveClick(DialogFragment dialog) {
EditText et=(EditText)findViewById(R.id.editText1);
dosyaAdi=et.getText().toString();
dosyayaYaz();
}
logcat的錯誤：
11-29 23:15:01.689: E/SensorManager(23506): thread start
11-29 23:15:16.684: E/AndroidRuntime(23506): FATAL EXCEPTION: main
11-29 23:15:16.684: E/AndroidRuntime(23506): java.lang.NullPointerException
11-29 23:15:16.684: E/AndroidRuntime(23506): at com.example.coordinates.MainActivity.onDialogPositiveClick(MainActivity.java:371)
11-29 23:15:16.684: E/AndroidRuntime(23506): at com.example.coordinates.dialogFragement$1.onClick(dialogFragement.java:54)
11-29 23:15:16.684: E/AndroidRuntime(23506): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:168)
11-29 23:15:16.684: E/AndroidRuntime(23506): at android.os.Handler.dispatchMessage(Handler.java:99)
11-29 23:15:16.684: E/AndroidRuntime(23506): at android.os.Looper.loop(Looper.java:137)
11-29 23:15:16.684: E/AndroidRuntime(23506): at android.app.ActivityThread.main(ActivityThread.java:4517)
11-29 23:15:16.684: E/AndroidRuntime(23506): at java.lang.reflect.Method.invokeNative(Native Method)
11-29 23:15:16.684: E/AndroidRuntime(23506): at java.lang.reflect.Method.invoke(Method.java:511)
11-29 23:15:16.684: E/AndroidRuntime(23506): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
11-29 23:15:16.684: E/AndroidRuntime(23506): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
11-29 23:15:16.684: E/AndroidRuntime(23506): at dalvik.system.NativeStart.main(Native Method)
dosyayaYaz（）函數：
private void dosyayaYaz(){
sm.unregisterListener(this); // this is the line 213
File myFile;
myFile= new File("sdcard/"+dosyaAdi.toString()+".csv");
try {
myFile.createNewFile();
FileOutputStream fOut = new FileOutputStream(myFile);
OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);
myOutWriter.append("X Koor;Y Koor;Z Koor");
myOutWriter.append("\n");
dataReader=db.rawQuery("SELECT * FROM Koordinatlar", null);
while(dataReader.moveToNext()){
Float xDeg=(dataReader.getFloat(dataReader.getColumnIndex("xKoor")));
Float yDeg=(dataReader.getFloat(dataReader.getColumnIndex("yKoor")));
Float zDeg=(dataReader.getFloat(dataReader.getColumnIndex("zKoor")));
myOutWriter.append(String.format("%f", xDeg)+";"+String.format("%f", yDeg)+";"+String.format("%f", zDeg));
myOutWriter.append("\n");
}
Toast toast=Toast.makeText(getBaseContext(), "Başarıyla Dosyaya Yazıldı",Toast.LENGTH_SHORT);
toast.show();
sm.registerListener(this, myAccelerometer, SensorManager.SENSOR_DELAY_UI);
}
catch(IOException ex){
Toast toast=Toast.makeText(getBaseContext(), "Dosyaya yazma sırasında bir hata oluştu"+" "+ex.toString(),Toast.LENGTH_LONG);
toast.show();
}
}
的onCreate功能：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fm=getFragmentManager();
b1=(Button)findViewById(R.id.button1);
b2=(Button)findViewById(R.id.button2);
b3=(Button)findViewById(R.id.button3);
x=(TextView)findViewById(R.id.textView4);
y=(TextView)findViewById(R.id.textView5);
z=(TextView)findViewById(R.id.textView6);
sm=(SensorManager)getSystemService(Context.SENSOR_SERVICE);
myAccelerometer= sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sm.registerListener(this, myAccelerometer,SensorManager.SENSOR_DELAY_UI);
veritabani= new VeriTabani(this);
db=veritabani.getWritableDatabase();
valuesX= new ArrayList<Float>();
valuesY= new ArrayList<Float>();
valuesZ= new ArrayList<Float>();
zamanDiyagrami= new ArrayList<Float>();
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
grafikGoruntule();
}
});
b2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
verileriSil();
}
});
b3.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
DialogFragment dialog = new dialogFragement();
dialog.show(fm, "MyDialogFragment");
}
});
}
發佈您的LogCat錯誤，以便我們可以看到發生了什麼。 – Sam
我剛加入它。 – metzelder
'com.example處的java.lang.NullPointerException。coordinates.MainActivity.dosyayaYaz（MainActivity.java:213）'DialogFragment沒問題。問題出在'dosyayaYaz（）'，特別是第213行。發佈這個方法並指明哪一行是213. – Sam