deng824 deng824
想交个朋友就加我啦
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安卓运行错误 public class MainActivity extends ActionBarActivity { Button btn_wr; TextView editText1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn_wr = (Button)this.findViewById(R.id.button1); editText1 = (TextView)this.findViewById(R.id.editText1); if (savedInstanceState == null) { getSupportFragmentManager().beginTransaction() .add(R.id.container, new PlaceholderFragment()) .commit(); } } private String getDataFromText() { return this.editText1.getText().toString(); } private boolean isExternalStorageWritable() { String state = Environment.getExternalStorageState(); if (Environment.MEDIA_MOUNTED.equals(state)) { return true; } return false; } private void writeToFile(String fileName, String content) { boolean flag = false; File file; FileOutputStream fos = null; if (isExternalStorageWritable()) file = new File(Environment.getExternalStorageDirectory(), fileName); else file = new File("/" + fileName); try { fos = new FileOutputStream(file); fos.write(content.getBytes()); flag = true; } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { try { fos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } System.out.println("===>write ok? " + flag); } public void writeToFile(View v) { writeToFile("hello", getDataFromText()); } 04-04 14:58:36.010: E/AndroidRuntime(10002): FATAL EXCEPTION: main 04-04 14:58:36.010: E/AndroidRuntime(10002): java.lang.IllegalStateException: Could not execute method of the activity 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.view.View$1.onClick(View.java:3598) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.view.View.performClick(View.java:4203) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.view.View$PerformClick.run(View.java:17549) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.os.Handler.handleCallback(Handler.java:725) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.os.Handler.dispatchMessage(Handler.java:92) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.os.Looper.loop(Looper.java:137) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.app.ActivityThread.main(ActivityThread.java:5068) 04-04 14:58:36.010: E/AndroidRuntime(10002): at java.lang.reflect.Method.invokeNative(Native Method) 04-04 14:58:36.010: E/AndroidRuntime(10002): at java.lang.reflect.Method.invoke(Method.java:511) 04-04 14:58:36.010: E/AndroidRuntime(10002): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 04-04 14:58:36.010: E/AndroidRuntime(10002): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 04-04 14:58:36.010: E/AndroidRuntime(10002): at dalvik.system.NativeStart.main(Native Method) 04-04 14:58:36.010: E/AndroidRuntime(10002): Caused by: java.lang.reflect.InvocationTargetException 04-04 14:58:36.010: E/AndroidRuntime(10002): at java.lang.reflect.Method.invokeNative(Native Method) 04-04 14:58:36.010: E/AndroidRuntime(10002): at java.lang.reflect.Method.invoke(Method.java:511) 04-04 14:58:36.010: E/AndroidRuntime(10002): at android.view.View$1.onClick(View.java:3593) 04-04 14:58:36.010: E/AndroidRuntime(10002): ... 11 more 04-04 14:58:36.010: E/AndroidRuntime(10002): Caused by: java.lang.NullPointerException 04-04 14:58:36.010: E/AndroidRuntime(10002): at com.example.sdtest.MainActivity.getDataFromText(MainActivity.java:41) 04-04 14:58:36.010: E/AndroidRuntime(10002): at com.example.sdtest.MainActivity.writeToFile(MainActivity.java:84) 04-04 14:58:36.010: E/AndroidRuntime(10002): ... 14 more 04-04 14:58:36.025: D/dalvikvm(10002): GC_CONCURRENT freed 198K, 10% free 3795K/4172K, paused 1ms+2ms, total 22ms
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