SD 卡读写异常急急急。。。

cuojue306 2016-08-26 01:14:03

MainActivity 代码：
public void click1(View v) {
try{
System.out.println("press");
File file = new File(Environment.getExternalStorageDirectory(), "a.txt");
FileOutputStream fos = new FileOutputStream(file);
fos.write("hellow".getBytes());
fos.close();
}catch(IOException e){
e.printStackTrace();
}
}

androidManifest.xml 中也加了权限：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

错误日志：
[color=#FFCC99]08-25 17:05:29.492: W/System.err(7336): java.io.FileNotFoundException: /mnt/sdcard/a.txt: open failed: EROFS (Read-only file system)
08-25 17:05:29.492: W/System.err(7336): at libcore.io.IoBridge.open(IoBridge.java:416)
08-25 17:05:29.492: W/System.err(7336): at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
08-25 17:05:29.503: W/System.err(7336): at java.io.FileOutputStream.<init>(FileOutputStream.java:73)
08-25 17:05:29.503: W/System.err(7336): at com.example.readandwrite.MainActivity.click1(MainActivity.java:32)
08-25 17:05:29.503: W/System.err(7336): at java.lang.reflect.Method.invokeNative(Native Method)
08-25 17:05:29.503: W/System.err(7336): at java.lang.reflect.Method.invoke(Method.java:511)
08-25 17:05:29.503: W/System.err(7336): at android.view.View$1.onClick(View.java:3594)
08-25 17:05:29.512: W/System.err(7336): at android.view.View.performClick(View.java:4204)
08-25 17:05:29.512: W/System.err(7336): at android.view.View$PerformClick.run(View.java:17355)
08-25 17:05:29.512: W/System.err(7336): at android.os.Handler.handleCallback(Handler.java:725)
08-25 17:05:29.512: W/System.err(7336): at android.os.Handler.dispatchMessage(Handler.java:92)
08-25 17:05:29.512: W/System.err(7336): at android.os.Looper.loop(Looper.java:137)
08-25 17:05:29.512: W/System.err(7336): at android.app.ActivityThread.main(ActivityThread.java:5041)
08-25 17:05:29.512: W/System.err(7336): at java.lang.reflect.Method.invokeNative(Native Method)
08-25 17:05:29.522: W/System.err(7336): at java.lang.reflect.Method.invoke(Method.java:511)
08-25 17:05:29.522: W/System.err(7336): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-25 17:05:29.522: W/System.err(7336): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-25 17:05:29.522: W/System.err(7336): at dalvik.system.NativeStart.main(Native Method)
08-25 17:05:29.522: W/System.err(7336): Caused by: libcore.io.ErrnoException: open failed: EROFS (Read-only file system)
08-25 17:05:29.542: W/System.err(7336): at libcore.io.Posix.open(Native Method)
08-25 17:05:29.542: W/System.err(7336): at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
08-25 17:05:29.542: W/System.err(7336): at libcore.io.IoBridge.open(IoBridge.java:400)
08-25 17:05:29.552: W/System.err(7336): ... 17 more[/color]

[color=#FF0000]请问大神这个是什么原因引起的，我已经加了SD卡的读写权限了？怎么解决。谢谢了[/color]

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