Android issues

1. Android studio 2.0

 

Error:Exception in thread "main" java.lang.UnsupportedClassVersionError: com/android/dx/command/Main : Unsupported major.minor version 52.0

 

解决办法：http://stackoverflow.com/questions/35990995/com-android-dx-command-main-unsupported-major-minor-version-52-0

//    buildToolsVersion "24.0.0 rc3"
    buildToolsVersion "23.0.2"



2. Manifests 权限已经设置，仍然有权限问题（Permission denied (missing INTERNET permission?)     ）

Permission denied (missing INTERNET permission?): But permission is given

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<application
    ...>
</application>

 

android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database

code：

try {
            String packageName="";//getPackageName();
            SQLiteDatabase.openOrCreateDatabase("/data/data/"+packageName+"/databases/test1.db", null);
            Log.v("killed", "DB created");
        } catch (Exception e) {
            Log.e("killed", "Create DB Error" + e.getMessage());
        }

permission：

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

 

出现这个问题，首先检查一下读写权限，发现权限没问题，一直这样的问题，在网上也查了许多，没有一个靠谱的。

最后才发现该db文件，只有在/data/data/packagename/目录下才有权限， 如果你出现这样的问题，只需要吧路径设置到相应app package下面

 

Details:

Order of defining tabs in Manifest:

1. Permissions
2. Applications
3. Receiver, Service, Metadata

3.AS 2.0 开启Instant Run出现的问题：Error:Access to the dex task is now impossible, starting with 1.4.0

Error:Access to the dex task is now impossible, starting with 1.4.0
1.4.0 introduces a new Transform API allowing manipulation of the .class files.
See more information: http://tools.android.com/tech-docs/new-build-system/transform-api

android老项目倒入后，android studio 2.0 自动更新gradle到2.0.0

http://blog.csdn.net/yzpbright/article/details/51231826

 

4. Android Fragment 

The method add(Fragment,String ) in the type FragmentTransaction is not applicable for the arguments (int, MyFragment)

import issue, 

今天遇到这样一个很奇葩的错误信息，后来查到我导入的包有问题  import android.app.Fragment;
import android.app.FragmentManager;   其实我应该使用的是  import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;   然后自己查看了一下API二者差别还是蛮大的   import android.app.Fragment 只能在API版本大于11的时候使用   而不包含getFragmentManager() 和 getSupportFragmentManager()  两个方法的   虽然在代码这样写不会报错的  但是  replace(int, Fragment, String)执行的时候会一直出现错误   提示上面那个错误信息

 

5. Error:(100, 43) error: package R does not exist

import yourpackage.R

 

6.  android.content.res.Resources$NotFoundException: String resource ID #0x1

今天使用TextView的setText方法遇到这个错误，原来是传入text的是int类型的，android不能自动转换成string类型，直接跑出这样的异常，我也是醉了

 

7. Android listview set on click item listener doesn't work

Item Layout的根控件设置其Android:descendantFocusability=”blocksDescendants”即可

 

 

8 include exception

 You must specifiy a layout in the include tag: <include layout="@layout/layoutID" />

layout.xml

android:layout=" xxx"

remove android