我正在尝试使用 android 连接到 azure 应用程序,但我收到此错误。这是我的代码和我的日志。
我已经检查了所有内容并且看起来是正确的,但我认为问题出在getApplicationContext()
上。我无法调试。
有人可以帮助我吗?
public class login extends Activity {
UserServicesImpl usv;
private EditText txtemail;
private EditText txtpassword;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
txtemail = (EditText) findViewById(R.id.txtemail);
txtpassword = (EditText) findViewById(R.id.txtpassword);
}
public void LoginKarrega(View view){
usv = new UserServicesImpl();
AlertDialog alertDialog = new AlertDialog.Builder(login.this).create();
alertDialog.setTitle("Alert");
if(usv.exist(txtemail.getText().toString(), txtpassword.getText().toString()) == true) {
alertDialog.setMessage("Sucessful login");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
}
else {
alertDialog.setMessage("wrong login");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
}
alertDialog.show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_login, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
logcat的:
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4007)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4002)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
at android.content.ContextWrapper.getApplicationContext(ContextWrapper.java:105)
at com.microsoft.windowsazure.mobileservices.notifications.MobileServicePush.<init>(MobileServicePush.java:134)
at com.microsoft.windowsazure.mobileservices.MobileServiceClient.initialize(MobileServiceClient.java:1473)
at com.microsoft.windowsazure.mobileservices.MobileServiceClient.<init>(MobileServiceClient.java:182)
at com.microsoft.windowsazure.mobileservices.MobileServiceClient.<init>(MobileServiceClient.java:158)
at ao.co.karrega.services.customers.UserServicesImpl.<init>(UserServicesImpl.java:39)
at ao.co.karrega.login.LoginKarrega(login.java:32)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4002)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
答案 0 :(得分:0)
使用以下代码解决此错误。目前您正在使用它而不是getApplicationContext()。
try {
mClient = new MobileServiceClient(
"https://newvbdemo.azure-mobile.net/",
"SUFYiOYEAlbEoKfsDgfWNIywaPSMhC29",
getApplicationContext()
);
mTable = mClient.getTable("Users",Users.class);
}catch (MalformedURLException e) {
e.printStackTrace();
}
答案 1 :(得分:0)
您的班级UserServicesImpl extends Activity
,但它似乎不是Activity
。
特别是,活动通常没有明确的构造函数,您不能在Activity
生命周期方法之前使用Context
作为onCreate()
。您的堆栈跟踪中的构建阶段<init>
太早了。
堆栈跟踪还表明您尝试在new
中使用LoginKarrega
实例化活动。永远不要自己使用new
实例化活动。
看起来你应该删除extends Activity
并传递Context
作为参数。