我有一个按钮（button1）。点击按钮，我试图显示colorpicker。 BaseViewable类扩展了Fragment。
public class Settingspreferences extends BaseViewable {
@Override
public View createView(final Context context, Object id, UserData extraData, IViewable viewable) {
super.createView(context, id, extraData, viewable);
final ColorPickerDialog colorPickerDialog = new ColorPickerDialog();
colorPickerDialog.initialize(R.string.dialog_title, new int[]{Color.CYAN, Color.LTGRAY, Color.BLACK, Color.BLUE, Color.GREEN, Color.MAGENTA, Color.RED,
Color.GRAY, Color.YELLOW}, Color.YELLOW, 3, 2);
colorPickerDialog.setOnColorSelectedListener(new ColorPickerSwatch.OnColorSelectedListener() {
@Override
public void onColorSelected(int color) {
Toast.makeText(context, "selectedColor : " + color, Toast.LENGTH_SHORT).show();
}
});
LinearLayout list_row2 = null;
TextView calenderItemTV2 = null;
ImageView calenderItemIV2 = null;
Button calenderCB2 = null;
LinearLayout parentLL2 = (LinearLayout) root.findViewById(R.id.rowHolder3);
calenderCB2 = (Button) list_row2.findViewById(R.id.calenderCB2);
calenderCB2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
colorPickerDialog.show(getActivity().getSupportFragmentManager(), "colorpicker");
}
});
`
以下是ColorPickerDialog类：
public class ColorPickerDialog extends DialogFragment implements ColorPickerSwatch.OnColorSelectedListener {
protected AlertDialog mAlertDialog;
protected int[] mColors = null;
protected int mColumns;
protected ColorPickerSwatch.OnColorSelectedListener mListener;
private ColorPickerPalette mPalette;
private ProgressBar mProgress;
protected int mSelectedColor;
protected int mSize;
protected int mTitleResId = R.string.color_picker_default_title;
private void refreshPalette() {
if ((this.mPalette != null) && (this.mColors != null))
this.mPalette.drawPalette(this.mColors, this.mSelectedColor);
}
public void initialize(int titleId, int[] colors, int selectedColor, int columns, int size) {
setArguments(titleId, columns, size);
setColors(colors, selectedColor);
}
public void onColorSelected(int selectedColor) {
if (this.mListener != null)
this.mListener.onColorSelected(selectedColor);
if ((getTargetFragment() instanceof ColorPickerSwatch.OnColorSelectedListener))
((ColorPickerSwatch.OnColorSelectedListener) getTargetFragment()).onColorSelected(selectedColor);
if (selectedColor != this.mSelectedColor) {
this.mSelectedColor = selectedColor;
this.mPalette.drawPalette(this.mColors, this.mSelectedColor);
}
dismiss();
}
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
if (getArguments() != null) {
this.mTitleResId = getArguments().getInt("title_id");
this.mColumns = getArguments().getInt("columns");
this.mSize = getArguments().getInt("size");
}
if (bundle != null) {
this.mColors = bundle.getIntArray("colors");
this.mSelectedColor = ((Integer) bundle.getSerializable("selected_color")).intValue();
}
}
public Dialog onCreateDialog(Bundle bundle) {
View view = LayoutInflater.from(getActivity()).inflate(R.layout.color_picker_dialog, null);
this.mProgress = ((ProgressBar) view.findViewById(android.R.id.progress));
this.mPalette = ((ColorPickerPalette) view.findViewById(R.id.color_picker));
this.mPalette.init(this.mSize, this.mColumns, this);
if (this.mColors != null)
showPaletteView();
this.mAlertDialog = new AlertDialog.Builder(getActivity()).setTitle(this.mTitleResId).setView(view).create();
return this.mAlertDialog;
}
public void onSaveInstanceState(Bundle bundle) {
super.onSaveInstanceState(bundle);
bundle.putIntArray("colors", this.mColors);
bundle.putSerializable("selected_color", Integer.valueOf(this.mSelectedColor));
}
public void setArguments(int titleId, int columns, int size) {
Bundle bundle = new Bundle();
bundle.putInt("title_id", titleId);
bundle.putInt("columns", columns);
bundle.putInt("size", size);
setArguments(bundle);
}
public void setColors(int[] colors, int selected) {
if ((this.mColors != colors) || (this.mSelectedColor != selected)) {
this.mColors = colors;
this.mSelectedColor = selected;
refreshPalette();
}
}
public void setOnColorSelectedListener(ColorPickerSwatch.OnColorSelectedListener onColorSelectedListener) {
this.mListener = onColorSelectedListener;
}
public void showPaletteView() {
if ((this.mProgress != null) && (this.mPalette != null)) {
this.mProgress.setVisibility(View.GONE);
refreshPalette();
this.mPalette.setVisibility(View.VISIBLE);
}
}
public void showProgressBarView() {
if ((this.mProgress != null) && (this.mPalette != null)) {
this.mProgress.setVisibility(View.VISIBLE);
this.mPalette.setVisibility(View.GONE);
}
}
}
我无法弄清楚问题，虽然我看过很多帖子类似于同一个问题但无法解决。请帮忙
请检查我的日志：
07-25 14:44:54.113 25526-25526/? W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'android.support.v4.app.FragmentTransaction android.support.v4.app.FragmentManager.beginTransaction()' on a null object reference
07-25 14:44:54.113 25526-25526/? W/System.err: at android.support.v4.app.DialogFragment.show(DialogFragment.java:137)
07-25 14:44:54.113 25526-25526/? W/System.err: at com.sap.rex.ui.CalendarSettingspreferences$2.onClick(CalendarSettingspreferences.java:258)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.view.View.performClick(View.java:5246)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.widget.TextView.performClick(TextView.java:10573)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.view.View$PerformClick.run(View.java:21256)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.os.Handler.handleCallback(Handler.java:739)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.os.Looper.loop(Looper.java:145)
07-25 14:44:54.113 25526-25526/? W/System.err: at android.app.ActivityThread.main(ActivityThread.java:6912)
07-25 14:44:54.113 25526-25526/? W/System.err: at java.lang.reflect.Method.invoke(Native Method)
07-25 14:44:54.113 25526-25526/? W/System.err: at java.lang.reflect.Method.invoke(Method.java:372)
07-25 14:44:54.113 25526-25526/? W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
07-25 14:44:54.113 25526-25526/? W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
答案 0 :(得分：0)
由于它是android.support.v4.app.DialogFragment，您应该使用getSupportFragmentManager()来显示对话框片段。
如果您从活动中展示：
colorPickerDialog.show(getSupportFragmentManager(), "colorpicker");
如果您从片段中显示：
colorPickerDialog.show(getActivity().getSupportFragmentManager(), "colorpicker");
编辑1： 使用
colorPickerDialog.show(getChildFragmentManager(), "colorpicker");