Android的相机上传图片，视频与进度条

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Source code and project link description here Android的相机上传图片，视频与进度条

面对错误服务器，不知道如何解决 - 我越来越对MainActivity.java和UploadActivity.java.I错误都和周围没有尝试过很多工作帮助

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)

来源

2016-09-20 VjyAnnd

你的错误堆栈跟踪告诉你：

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

所以问题是，当你这样做：

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

getActionBar（）的调用返回null。

有许多的原因getActionBar（）可能返回null，但最常见的是，你应该调用的

getSupportActionBar()

代替

getActionBar()

那么请尝试更换所有实例“getActionBar（）”代码中的“getSupportActionBar（）”

来源

2016-09-20 13:05:47 Luke

Android的相机上传图片，视频与进度条

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