Android development Tips

Android development Tips

Some tips that are frequently used in Android development.

1. Download folder

Absolute path

/storage/emulated/0/Download/xxx

Traversal

        File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);        File[] files = file.listFiles();        for (int i = 0; i < files.length; ++i) {            Log.e(TAG, files[i].getAbsolutePath());        }

2. ButterKnife multiple parameters

Bind multiple parameters

    @OnClick({            R.id.dialog_dau_share_wx,            R.id.dialog_dau_share_wx_timeline,            R.id.dialog_dau_share_weibo,            R.id.dialog_dau_share_qq    })

3. How to Use submodule

The submodule and git can be synchronized in real time.
Add

git submodule add https://github.com/SpikeKing/DroidPlugin.git DroidPlugin

Use

git submodule update --init --recursive

Import, with more than one path. No colon (:) is added before (:).

include ':app', 'DroidPlugin:project:Libraries:DroidPlugin'

Reference

compile project(':DroidPlugin:project:Libraries:DroidPlugin')

4. Update the Fork library of Github.

Reference

5. Check whether the App is installed

Use PackageManager.

// Check whether the App has installed private boolean appInstalledOrNot (String uri) {PackageManager pm = getPackageManager (); boolean app_installed; try {pm. getPackageInfo (uri, PackageManager. GET_ACTIVITIES); app_installed = true;} catch (PackageManager. nameNotFoundException e) {app_installed = false;} return app_installed ;}

6. Canvas re-painting

Invalidate (). Reference.

7. default button clicking Effect

Ripple Effect (5.0 +), shadow effect (5.0 -).

android:background="?android:attr/selectableItemBackground"

Inherited Style

Note: @ android: style/ButtonBar

8. Proguard removes Log information

Log. I,. v is deleted by default. You can specify to delete. d,. e. reference.

# Delete Log-assumenosideeffects class android. util. log {*;}-assumenosideeffects class android. util. log {public static *** d (...); public static *** e (...);}

9. Simplify database usage

When using the database, the operation is somewhat complicated. The Sugar database is simplified for reference.

compile 'com.github.satyan:sugar:1.3'

10. Click the EditView of the filled link.

Add a space ("\ u200B") at the end ").

// Set the EditText private void setEditClickable () {mEtEditText. setMovementMethod (LinkMovementMethod. getInstance (); Spannable spannable = new SpannableString ("http://www.baidu.com"); Linkify. addLinks (spannable, Linkify. WEB_URLS); // added a zero-width space (? \ U200B ???), To the final position. Otherwise, the link CharSequence text = TextUtils. concat (spannable, "\ u200B"); mEtEditText. setText (text);} will be triggered );}

OK. That's all!