ShowDialog onClick偏好
我有一个PreferenceActivity，其中有一个偏好。我想点击这个首选项将打开另一个类中的对话框。类亮度包含要呈现的对话框。这是密码。
// This is the PreferenceActivity Class (Settings)
Preference bright;
bright = (Preference) this.findPreference("bri");
bright.setOnPreferenceClickListener( new OnPreferenceClickListener() {
public boolean onPreferenceClick(Preference preference) {
Brightness brightness = new Brightness();
brightness.ShowDialog();
return true;
}
});光明课
public class Brightness extends Activity{
private SeekBar brightbar;
private int brightness;
@SuppressWarnings("unused")
private ContentResolver cResolver;
private Window window;
TextView txtPerc;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ShowDialog();
}
public void ShowDialog() {
final AlertDialog.Builder popDialog = new AlertDialog.Builder(getApplicationContext());
final LayoutInflater inflater = (LayoutInflater) this.getSystemService(LAYOUT_INFLATER_SERVICE);
final View Viewlayout = inflater.inflate(R.layout.dialog_brightness, (ViewGroup) findViewById(R.id.layout_dialog));
popDialog.setTitle("Set Brightness");
popDialog.setView(Viewlayout);
brightbar = (SeekBar) findViewById(R.id.brightbar);
txtPerc = (TextView) findViewById(R.id.txtPercentage);
cResolver = getContentResolver();
window = getWindow();
brightbar.setMax(255);
brightbar.setKeyProgressIncrement(1);
brightbar = (SeekBar) findViewById(R.id.brightbar);
txtPerc = (TextView) findViewById(R.id.txtPercentage);
cResolver = getContentResolver();
window = getWindow();
brightbar.setMax(255);
brightbar.setKeyProgressIncrement(1);
try
{
brightness = Settings.System.getInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS);
float perc = (brightness /(float)255)*100;
txtPerc.setText((int)perc +" %");
}
catch (SettingNotFoundException e)
{
Log.e("Error", "Cannot access system brightness");
e.printStackTrace();
}
brightbar.setProgress(brightness);
brightbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener()
{
public void onStopTrackingTouch(SeekBar seekBar)
{
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, brightness);
LayoutParams layoutpars = window.getAttributes();
layoutpars.screenBrightness = brightness / (float)255;
window.setAttributes(layoutpars);
}
public void onStartTrackingTouch(SeekBar seekBar)
{
}
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
{
brightness = progress;
float perc = (brightness /(float)255)*100;
txtPerc.setText((int)perc +" %");
}
});
popDialog.setNeutralButton("Close",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
popDialog.create();
popDialog.show();
}
}问题是，当我点击这个偏好，应用程序崩溃！这是逻辑猫
11-11 18:03:57.788: E/AndroidRuntime(18672)：致命例外:主要11-11 18:03:57.788: E/AndroidRuntime(18672)：java.lang.NullPointerException 11-11 18:03:57.788: E/AndroidRuntime(18672)：at com.packagename.Brightness.ShowDialog(Brightness.java:39) 11-11 18:03:57.788: E/AndroidRuntime(18672)：at com.packagename.Brightness.ShowDialog(Brightness.java:39) 11-11 : 18:03:57.788: E/AndroidRuntime(18672)：com.packagename.Settings$1.onPreferenceClick(Settings.java:48) 11-11 18:57.788: E/AndroidRuntime(18672)：android.preference.Preference.performClick(Preference.java:952) 11-11 18:03:57.788: E/AndroidRuntime(18672)：android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:215) 11-11 18:03:57。788: E/AndroidRuntime(18672)：在android.widget.AdapterView.performItemClick(AdapterView.java:297) 11-11 18:03:57.788: E/AndroidRuntime(18672)：在android.widget.AbsListView.performItemClick(AbsListView.java:1100) 11-11 18:03:57.788: E/AndroidRuntime(18672)：at android.widget.AbsListView$PerformClick.run(AbsListView.java:2788) 11-11 18:03:57.788: E/AndroidRuntime(18672)：atandroid.widget.AbsListView$1.run(AbsListView.java:3463) 11-11 18:03:57.788: E/AndroidRuntime(18672)：android.os.Handler.handleCallback(Handler.java:730) 11-11 18:57.788: E/AndroidRuntime(18672)：在android.os.Handler.dispatchMessage(Handler.java:92) 11-11 18:03:57.788: E/AndroidRuntime(18672)：at android.os.Looper.loop11-11 18:03:57.788: E/AndroidRuntime(18672)：android.app.ActivityThread.main(ActivityThread.java:5289) 11-11 18:03:57.788: E/AndroidRuntime(18672)：at java.lang.reflect.Method.invokeNative(原生方法) 11-11 18:03:57.788: E/AndroidRuntime(18672)：at java.lang.reflect.Method.invoke(Method.java:525) 11-11 18:03:57.788: E/AndroidRuntime(18672)：在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739) 11-11 18:57.788: E/AndroidRuntime(18672)：在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555) 11-11 18:03:57.788: E/AndroidRuntime(18672)：at dalvik.system.NativeStart.main(原生方法)
回答 2
Stack Overflow用户
发布于 2013-11-11 17:23:22
要显示对话框，必须从对话框或片段中扩展亮度，而不是活动。
Stack Overflow用户
发布于 2013-11-11 18:01:38
在这里，活动代码：
public class MainActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyDialog dialog = new MyDialog();
Bundle arguments = new Bundle();
arguments.putString(MyDialog.ARGS, "Message");
dialog.setArguments(arguments);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(dialog, dialog.getTag());
ft.commitAllowingStateLoss();
}
}对话：
public class MyDialog extends DialogFragment {
public static final String ARGS = "ARGS";
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
Bundle args = getArguments();
String message;
if (args.containsKey(ARGS)) message = args.getString(ARGS); else message = "Sorry";
builder.setTitle("Title")
.setMessage(message)
.setNeutralButton("OK", null);
return builder.create();
}
}如何在PrefernceActivity中使用它，您应该考虑一下。
https://stackoverflow.com/questions/19912063
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