Android的相機上傳圖片，視頻與進度條

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Source code and project link description here Android的相機上傳圖片，視頻與進度條

面對錯誤服務器，不知道如何解決 - 我越來越對MainActivity.java和UploadActivity.java.I錯誤都和周圍沒有嘗試過很多工作幫助

09-20 18:06:37.279 21398-21398/info.androidhive.camerafileupload E/AndroidRuntime: FATAL EXCEPTION: main 
                       Process: info.androidhive.camerafileupload, PID: 21398 
                       java.lang.RuntimeException: Unable to start activity ComponentInfo{info.androidhive.camerafileupload/info.androidhive.camerafileupload.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setBackgroundDrawable(android.graphics.drawable.Drawable)' on a null object reference 
                        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) 
                        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
                        at android.app.ActivityThread.-wrap11(ActivityThread.java) 
                        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
                        at android.os.Handler.dispatchMessage(Handler.java:102) 
                        at android.os.Looper.loop(Looper.java:148) 
                        at android.app.ActivityThread.main(ActivityThread.java:5417) 
                        at java.lang.reflect.Method.invoke(Native Method) 
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
                       Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setBackgroundDrawable(android.graphics.drawable.Drawable)' on a null object reference 
                        at info.androidhive.camerafileupload.MainActivity.onCreate(MainActivity.java:46) 
                        at android.app.Activity.performCreate(Activity.java:6237) 
                        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
                        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
                        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)  
                        at android.app.ActivityThread.-wrap11(ActivityThread.java)  
                        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)  
                        at android.os.Handler.dispatchMessage(Handler.java:102)  
                        at android.os.Looper.loop(Looper.java:148)  
                        at android.app.ActivityThread.main(ActivityThread.java:5417)  
                        at java.lang.reflect.Method.invoke(Native Method)  
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

來源

2016-09-20 VjyAnnd

你的錯誤堆棧跟蹤告訴你：

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setBackgroundDrawable(android.graphics.drawable.Drawable)' on a null object reference

所以問題是，當你這樣做：

getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor(getResources().getString(R.color.action_bar))));

getActionBar（）的調用返回null。

有許多的原因getActionBar（）可能返回null，但最常見的是，你應該調用的

getSupportActionBar()

代替

getActionBar()

那麼請嘗試更換所有實例「getActionBar（）」代碼中的「getSupportActionBar（）」

來源

2016-09-20 13:05:47 Luke

Android的相機上傳圖片，視頻與進度條

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