Question

这是主要活动，我点击按钮

    public class NewAddMarketingProg extends Activity implements OnClickListener {
    private StartAppAd startAppAd;



    String note_detail;
    ListView lvNote;
    String[] data;
    private int mIndex;
    private MarketingProgramsAdapter adapter;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
/*      StartAppSDK.init(this, getString(R.string.account_id),
                getString(R.string.app_id), true);*/



        setContentView(R.layout.newaddmarketingprog);
        context = this;
        init();

        lvNote.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1,
                    int position, long arg3) {

                mIndex = position;
                arg1.showContextMenu();
            }
        });

        registerForContextMenu(lvNote);
        startAppAd = new StartAppAd(this);

        startAppAd.showAd(); // show the ad
        startAppAd.loadAd(); // load the next ad

    }

    private void init() {
        MarketingPrograms.listOfMarketingPrograms.clear();
        lvNote = (ListView) findViewById(R.id.lvNotes);
        getDataFromDB();

        Button bAddNote = (Button) findViewById(R.id.btnAdd);

        bAddNote.setOnClickListener(this);

    }

    private void getDataFromDB() {
        DatabaseMarketingPrograms infoNote = new DatabaseMarketingPrograms(this);

        infoNote.openNote();
        infoNote.getDataNote();
        infoNote.getRowDataNote();
        infoNote.closeNote();

        adapter = new MarketingProgramsAdapter(context);
        lvNote.setAdapter(adapter);

    }

    @Override
    public void onClick(View v) {

        switch (v.getId()) {
        case R.id.bAddNote:
            Intent i = new Intent(this, AddMarketingProgram.class);

            i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            startActivity(i);
            finish();
            break;
        }
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
            ContextMenuInfo menuInfo) {
        MenuInflater m = getMenuInflater();
        m.inflate(R.menu.noteotions, menu);
        super.onCreateContextMenu(menu, v, menuInfo);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.view) {

            int id = MarketingPrograms.listOfMarketingPrograms.get(mIndex).getId();
            Intent e = new Intent(this, ViewMarketingPrograms.class);
            e.putExtra("id", id);
            startActivity(e);

        } else if (item.getItemId() == R.id.update) {
        int id = MarketingPrograms.listOfMarketingPrograms.get(mIndex).getId();
            Intent e = new Intent(this, AddMarketingProgram.class);
            e.putExtra("mIsUpdate", true);
            e.putExtra("mIndex", mIndex);
            e.putExtra("id", id);
            startActivity(e);

        } else if (item.getItemId() == R.id.delete) {
            int id = MarketingPrograms.listOfMarketingPrograms.get(mIndex).getId();
            DatabaseMarketingPrograms delete = new DatabaseMarketingPrograms(NewAddMarketingProg.this);

            int flag = delete.deleteEntry(id);
            if (flag > 0) {
                Toast.makeText(getApplicationContext(), "Deleted",
                        Toast.LENGTH_SHORT).show();
                MarketingPrograms.listOfMarketingPrograms.remove(mIndex);
                adapter.notifyDataSetChanged();
            } else {
                Toast.makeText(getApplicationContext(), "Could n't be Deleted",
                        Toast.LENGTH_SHORT).show();
            }
        }
        return super.onContextItemSelected(item);
    }
    @Override
    protected void onResume() {

        super.onResume();
        startAppAd.onResume();
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        startAppAd.onPause();

    }
    @Override
    public void onBackPressed() {
        startAppAd.onBackPressed();
        Intent i=new Intent(NewAddMarketingProg.this,MainActivity.class);
        startActivity(i);
        finish();
        super.onBackPressed();
    }

}

这是我想要点击按钮
打开的活动

public class AddMarketingProgram extends Activity implements OnClickListener {
TextView /* tvDate, */tvSelectDate;
EditText etName,etBudget;
Button btnSave;
boolean mIsUpdate = false;
Context context;
private int id;
private int mIndex;
private DatePickerDialog fromDatePickerDialog;
private SimpleDateFormat dateFormatter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.addmarketingprograms);
    context = this;

    etName = (EditText) findViewById(R.id.etName);
    etBudget = (EditText) findViewById(R.id.etBudget);
    tvSelectDate = (TextView) findViewById(R.id.tvSelectDate);
    tvSelectDate.setOnClickListener(this);

    btnSave = (Button) findViewById(R.id.btnSave);
    btnSave.setOnClickListener(this);

    Bundle bundle = getIntent().getExtras();
    if (bundle != null) {
        mIsUpdate = bundle.getBoolean("mIsUpdate", false);
        if (mIsUpdate) {

            mIndex = bundle.getInt("mIndex");
            MarketingPrograms note = MarketingPrograms.listOfMarketingPrograms.get(mIndex);
            String name = note.getName();
            String date = note.getDate();
            int budget=note.getBudget();
            etName.setText(name);
            tvSelectDate.setText(date);
            etBudget.setText(String.valueOf(budget));

            btnSave.setText("Update");

        }
    }

    // Get Current Date and time
    Calendar c = Calendar.getInstance();
    dateFormatter = new SimpleDateFormat("dd,MMM yyyy");
    tvSelectDate.setText(dateFormatter.format(c.getTime()));

    // Initrialize date picker
    setDateTimeField();
}

@Override
public void onBackPressed() {
    Intent i = new Intent(context, NewAddClassNotes.class);
    startActivity(i);
    finish();
}

@Override
public void onClick(View arg0) {
    switch (arg0.getId()) {
    case R.id.btnSave:
        if (mIsUpdate) {
            updateNote();

        } else {
            saveNote();
        }
        break;
    case R.id.tvSelectDate:
        fromDatePickerDialog.show();
    }
}

private void updateNote() {

    DatabaseMarketingPrograms update = new DatabaseMarketingPrograms(context);
    update.openNote();
    String name = etName.getText().toString();
    String date = tvSelectDate.getText().toString();
    int Budget=Integer.parseInt(etBudget.getText().toString());

    boolean flag = update.editEntry(name, Budget, date, MarketingPrograms.listOfMarketingPrograms.get(mIndex).getId());
    update.closeNote();
    if (flag) {
        Toast.makeText(getApplicationContext(), "Update Successfully",
                Toast.LENGTH_LONG).show();
        onBackPressed();
    } else {
        Toast.makeText(getApplicationContext(), "Unable to update.",
                Toast.LENGTH_LONG).show();
    }
}

private void saveNote() {
    try {
        String name = etName.getText().toString();
        int budget=Integer.parseInt(etBudget.getText().toString());   
        String date = tvSelectDate.getText().toString();
        DatabaseMarketingPrograms entry = new DatabaseMarketingPrograms(context);

        entry.openNote();
        long flag = entry.createEntryNote(name, budget, date);

        entry.closeNote();

        if (flag > 0) {
            Toast.makeText(getApplicationContext(), "Save Successfully",
                    Toast.LENGTH_LONG).show();
            onBackPressed();
        } else {
            Toast.makeText(getApplicationContext(), "Unable to Save.",
                    Toast.LENGTH_LONG).show();
        }
    } catch (Exception e) {
        Toast.makeText(getApplicationContext(), "Unable to Save.",
                Toast.LENGTH_LONG).show();
    }
}

private void setDateTimeField() {

    Calendar newCalendar = Calendar.getInstance();
    fromDatePickerDialog = new DatePickerDialog(this,
            new OnDateSetListener() {

                public void onDateSet(DatePicker view, int year,
                        int monthOfYear, int dayOfMonth) {
                    Calendar newDate = Calendar.getInstance();
                    newDate.set(year, monthOfYear, dayOfMonth);
                    tvSelectDate.setText(dateFormatter.format(newDate
                            .getTime()));
                }
            }, newCalendar.get(Calendar.YEAR),
            newCalendar.get(Calendar.MONTH),
            newCalendar.get(Calendar.DAY_OF_MONTH));
}

}

Answer 1

您使用ID R.id.btnAdd 来获取按钮实例，而在onClick中，您使用ID R.id.bAddNote 来执行onClick。您必须更正此问题才能使其正常工作。

这里是init（）

    Button bAddNote = (Button) findViewById(R.id.btnAdd); // Button ID, this seems correct, otherwise you would have got **NPE** in next line.

在onClick

    case R.id.bAddNote: //different resource ID, change this to btnAdd.

您忘记为按钮ID添加大小写，或者您错误地在不同位置添加了不同的ID。我怀疑onClick案例ID错误。

Answer 2

在您的情况下，使用不同的按钮ID。

在onClick上：

案例 R.id.bAddNote ：//此处替换为 R.id.btnAdd

我的按钮不起作用

2 个答案: