Java Android使用ActionBar在Asynctask中的活动之间进行更改(切换)
我有两个活动:LoginActivity和MainActivityJava Android使用ActionBar在Asynctask中的活动之间进行更改(切换),java,android,android-asynctask,android-activity,android-actionbar,Java,Android,Android Asynctask,Android Activity,Android Actionbar,我有两个活动:LoginActivity和MainActivity public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ActionBar actionBar = getActionBar(); actionBar.setNavigationMode(ActionBar.N
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
我在LoginActivity中使用了AsyncTask,如下所示:
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if(result.contains("success")) { //login success
Intent intent_name = new Intent();
intent_name.setClass(LoginActivity.this,MainActivity.class);
startActivity(intent_name);
} else {
}
}
(我将LoginActivity.this更改为getApplicationContext()和McContext,后者通过构造函数接收上下文)
在主要活动中
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
当我启动应用程序并从服务器获得“成功”时
“java.lang.RuntimeException:无法启动活动组件信息”
由MainActivity.onCreate(MainActivity.java:25)触发
java:24是ActionBar ActionBar=getActionBar()的位置代码>位于
有什么可疑的错误吗?谢谢大家!
- 另外,我希望包含登录cookie(会话),以便与MainActivity、MainActivity中的webView共享。我该怎么做
下面是Logcat
30904-30904/com.sintranet.inf.mini E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sintranet.inf.mini/com.sintranet.inf.mini.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2073)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2098)
at android.app.ActivityThread.access$600(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1204)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4886)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.sintranet.inf.mini.MainActivity.onCreate(MainActivity.java:24)
at android.app.Activity.performCreate(Activity.java:5240)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1082)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2037)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2098)
at android.app.ActivityThread.access$600(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1204)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4886)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
Actionbar可能由于应用程序主题而为空
请从应用程序/活动标记的android清单中检查您的应用程序主题,并检查java代码中的窗口主题未更改。发布完整的堆栈跟踪。@Raghunandan添加了logcatwhat is MainActivity.java第24行???@Raghunandan该行已更改..:24是actionBar.setNavigationMode(actionBar.NAVIGATION\u MODE\u选项卡)<代码>操作栏
为空,请修复它