我的mms应用程序需要这个文件的帮助。 getActivity()会导致构建错误。
错误： cannot find symbol: method getActivity()
到目前为止，我已经尝试了很多工作来完成这项工作，比如extends PreferenceFragment - 然后getActivity()很好，但是这个解决方案打破了很多其他的东西。
有谁知道我为什么会收到此错误？
我的代码：
package com.android.mms.themes;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.graphics.Rect;
import android.net.Uri;
import android.os.Bundle;
import android.os.SystemProperties;
import android.preference.CheckBoxPreference;
import android.preference.EditTextPreference;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.PreferenceGroup;
import android.preference.PreferenceManager;
import android.preference.Preference.OnPreferenceChangeListener;
import android.preference.PreferenceScreen;
import android.provider.MediaStore;
import android.text.Spannable;
import android.util.Log;
import android.view.Display;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import com.android.mms.R;
import com.android.mms.ui.ColorPickerPreference;
public class ThemesMessageList extends PreferenceActivity implements
Preference.OnPreferenceChangeListener {
// Menu entries
private static final int THEMES_RESTORE_DEFAULTS = 1;
// Layout Style
public static final String PREF_TEXT_CONV_LAYOUT = "pref_text_conv_layout";
// Msg background
public static final String PREF_MESSAGE_BG = "pref_message_bg";
private static final String CUSTOM_IMAGE = "message_list_image.jpg";
private static final int REQUEST_PICK_WALLPAPER = 201;
private static final int SELECT_WALLPAPER = 5;
// Bubble types
public static final String PREF_BUBBLE_TYPE = "pref_bubble_type";
public static final String PREF_BUBBLE_FILL_PARENT = "pref_bubble_fill_parent";
// Checkbox preferences
public static final String PREF_USE_CONTACT = "pref_use_contact";
public static final String PREF_SHOW_AVATAR = "pref_show_avatar";
// Colorpicker preferences send
public static final String PREF_SENT_TEXTCOLOR = "pref_sent_textcolor";
public static final String PREF_SENT_CONTACT_COLOR = "pref_sent_contact_color";
public static final String PREF_SENT_DATE_COLOR = "pref_sent_date_color";
public static final String PREF_SENT_TEXT_BG = "pref_sent_text_bg";
public static final String PREF_SENT_SMILEY = "pref_sent_smiley";
// Colorpicker preferences received
public static final String PREF_RECV_TEXTCOLOR = "pref_recv_textcolor";
public static final String PREF_RECV_CONTACT_COLOR = "pref_recv_contact_color";
public static final String PREF_RECV_DATE_COLOR = "pref_recv_date_color";
public static final String PREF_RECV_TEXT_BG = "pref_recv_text_bg";
public static final String PREF_RECV_SMILEY = "pref_recv_smiley";
// message background
ColorPickerPreference mMessageBackground;
// send
ColorPickerPreference mSentTextColor;
ColorPickerPreference mSentDateColor;
ColorPickerPreference mSentContactColor;
ColorPickerPreference mSentTextBgColor;
ColorPickerPreference mSentSmiley;
// received
ColorPickerPreference mRecvTextColor;
ColorPickerPreference mRecvContactColor;
ColorPickerPreference mRecvDateColor;
ColorPickerPreference mRecvTextBgColor;
ColorPickerPreference mRecvSmiley;
private CheckBoxPreference mUseContact;
private CheckBoxPreference mShowAvatar;
private CheckBoxPreference mBubbleFillParent;
private ListPreference mTextLayout;
private ListPreference mBubbleType;
private Preference mCustomImage;
private SharedPreferences sp;
protected Context mContext;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mContext = getActivity();
loadThemePrefs();
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
}
public void loadThemePrefs() {
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.preferences_themes_msglist);
PreferenceScreen prefSet = getPreferenceScreen();
sp = PreferenceManager.getDefaultSharedPreferences(this);
mUseContact = (CheckBoxPreference) prefSet.findPreference(PREF_USE_CONTACT);
mShowAvatar = (CheckBoxPreference) prefSet.findPreference(PREF_SHOW_AVATAR);
mBubbleFillParent = (CheckBoxPreference) prefSet.findPreference(PREF_BUBBLE_FILL_PARENT);
mTextLayout = (ListPreference) findPreference(PREF_TEXT_CONV_LAYOUT);
mTextLayout.setOnPreferenceChangeListener(this);
mTextLayout.setSummary(mTextLayout.getEntry());
mBubbleType = (ListPreference) findPreference(PREF_BUBBLE_TYPE);
mBubbleType.setOnPreferenceChangeListener(this);
mBubbleType.setSummary(mBubbleType.getEntry());
mCustomImage = findPreference("pref_custom_image");
mMessageBackground = (ColorPickerPreference) findPreference(PREF_MESSAGE_BG);
mMessageBackground.setOnPreferenceChangeListener(this);
mSentTextColor = (ColorPickerPreference) findPreference(PREF_SENT_TEXTCOLOR);
mSentTextColor.setOnPreferenceChangeListener(this);
mSentContactColor = (ColorPickerPreference) findPreference(PREF_SENT_TEXTCOLOR);
mSentContactColor.setOnPreferenceChangeListener(this);
mSentDateColor = (ColorPickerPreference) findPreference(PREF_SENT_TEXTCOLOR);
mSentDateColor.setOnPreferenceChangeListener(this);
mSentTextBgColor = (ColorPickerPreference) findPreference(PREF_SENT_TEXTCOLOR);
mSentTextBgColor.setOnPreferenceChangeListener(this);
mSentSmiley = (ColorPickerPreference) findPreference(PREF_SENT_SMILEY);
mSentSmiley.setOnPreferenceChangeListener(this);
mRecvTextColor = (ColorPickerPreference) findPreference(PREF_RECV_TEXTCOLOR);
mRecvTextColor.setOnPreferenceChangeListener(this);
mRecvContactColor = (ColorPickerPreference) findPreference(PREF_RECV_TEXTCOLOR);
mRecvContactColor.setOnPreferenceChangeListener(this);
mRecvDateColor = (ColorPickerPreference) findPreference(PREF_RECV_TEXTCOLOR);
mRecvDateColor.setOnPreferenceChangeListener(this);
mRecvTextBgColor = (ColorPickerPreference) findPreference(PREF_RECV_TEXT_BG);
mRecvTextBgColor.setOnPreferenceChangeListener(this);
mRecvSmiley = (ColorPickerPreference) findPreference(PREF_RECV_SMILEY);
mRecvSmiley.setOnPreferenceChangeListener(this);
}
@Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
boolean result = false;
if (preference == mMessageBackground) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mMessageBackground.setSummary(hex);
} else if (preference == mSentTextColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mSentTextColor.setSummary(hex);
} else if (preference == mSentContactColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mSentContactColor.setSummary(hex);
} else if (preference == mSentDateColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mSentDateColor.setSummary(hex);
} else if (preference == mSentTextBgColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mSentTextBgColor.setSummary(hex);
} else if (preference == mSentSmiley) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mSentSmiley.setSummary(hex);
} else if (preference == mRecvTextColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mRecvTextColor.setSummary(hex);
} else if (preference == mRecvContactColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mRecvContactColor.setSummary(hex);
} else if (preference == mRecvDateColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mRecvDateColor.setSummary(hex);
} else if (preference == mRecvTextBgColor) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mRecvTextBgColor.setSummary(hex);
} else if (preference == mRecvSmiley) {
String hex = ColorPickerPreference.convertToARGB(Integer.valueOf(String
.valueOf(newValue)));
mRecvSmiley.setSummary(hex);
} else if (preference == mTextLayout) {
int index = mTextLayout.findIndexOfValue((String) newValue);
mTextLayout.setSummary(mTextLayout.getEntries()[index]);
return true;
} else if (preference == mBubbleType) {
int index = mBubbleType.findIndexOfValue((String) newValue);
mBubbleType.setSummary(mBubbleType.getEntries()[index]);
return true;
}
return result;
}
@Override
public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
boolean value;
if (preference == mCustomImage) {
Display display = getActivity().getWindowManager().getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
Rect rect = new Rect();
Window window = getActivity().getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rect);
int statusBarHeight = rect.top;
int contentViewTop = window.findViewById(Window.ID_ANDROID_CONTENT).getTop();
int titleBarHeight = contentViewTop - statusBarHeight;
Intent intent = new Intent(Intent.ACTION_GET_CONTENT, null);
intent.setType("image/*");
intent.putExtra("crop", "true");
boolean isPortrait = getResources()
.getConfiguration().orientation
== Configuration.ORIENTATION_PORTRAIT;
intent.putExtra("aspectX", isPortrait ? width : height - titleBarHeight);
intent.putExtra("aspectY", isPortrait ? height - titleBarHeight : width);
intent.putExtra("outputX", width);
intent.putExtra("outputY", height);
intent.putExtra("scale", true);
intent.putExtra("scaleUpIfNeeded", true);
intent.putExtra(MediaStore.EXTRA_OUTPUT, getCustomImageExternalUri());
intent.putExtra("outputFormat", Bitmap.CompressFormat.PNG.toString());
startActivityForResult(intent, REQUEST_PICK_WALLPAPER);
return true;
} else if (preference == mUseContact) {
value = mUseContact.isChecked();
} else if (preference == mShowAvatar) {
value = mShowAvatar.isChecked();
} else if (preference == mBubbleFillParent) {
value = mShowAvatar.isChecked();
}
return super.onPreferenceTreeClick(preferenceScreen, preference);
}
private void restoreThemeMessageListDefaultPreferences() {
PreferenceManager.getDefaultSharedPreferences(this).edit().clear().apply();
setPreferenceScreen(null);
loadThemePrefs();
}
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.clear();
menu.add(R.menu.themes_message_list);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case THEMES_RESTORE_DEFAULTS:
restoreThemeMessageListDefaultPreferences();
return true;
case R.id.custom_image_delete:
deleteCustomImage();
return true;
case android.R.id.home:
// The user clicked on the Messaging icon in the action bar. Take them back from
// wherever they came from
finish();
return true;
}
return false;
}
private void deleteCustomImage() {
mContext.deleteFile(CUSTOM_IMAGE);
}
private Uri getCustomImageExternalUri() {
File dir = mContext.getExternalCacheDir();
File wallpaper = new File(dir, CUSTOM_IMAGE);
return Uri.fromFile(wallpaper);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == Activity.RESULT_OK) {
if (requestCode == REQUEST_PICK_WALLPAPER) {
FileOutputStream wallpaperStream = null;
try {
wallpaperStream = mContext.openFileOutput(CUSTOM_IMAGE,
Context.MODE_WORLD_READABLE);
} catch (FileNotFoundException e) {
return; // NOOOOO
}
Uri selectedImageUri = getCustomImageExternalUri();
Bitmap bitmap = BitmapFactory.decodeFile(selectedImageUri.getPath());
bitmap.compress(Bitmap.CompressFormat.PNG, 100, wallpaperStream);
}
}
}
public void copy(File src, File dst) throws IOException {
InputStream in = new FileInputStream(src);
FileOutputStream out = new FileOutputStream(dst);
// Transfer bytes from in to out
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
}
}
答案 0 :(得分：19)
getActivity()类中不存在 Activity，因此要获得您的活动的Context，请改用this：
mContext = this;
答案 1 :(得分：9)
PreferenceActivity没有getActivity方法，因为它是Activity。只需指定您的上下文：mContext = this;
getActivity()是Fragment类的方法。
此外，除非您尝试在此课程之外引用mContext，否则您可以将它们全部丢弃，而只需使用this。
答案 2 :(得分：-7)
试试这个： -
右键点击项目＆gt;属性＆gt; java build path＆gt;单击Libraries选项卡＆gt;单击Add Library Button＆gt;选择Jre系统库＆gt;下一步＆gt;完成＆gt;确定