Java setOnClickListener(android.view.view$OnClickListener)和#x27;关于空对象引用
我有一个错误:Java setOnClickListener(android.view.view$OnClickListener)和#x27;关于空对象引用,java,android,object,Java,Android,Object,我有一个错误: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at mt.edu.mcast.navigationfragmentsexample.BlankFragment2.onCreateView(BlankFragment2.java:92)
这是java BlankFragment2中的代码:
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_blank_fragment2,container,false);
final EditText etName = (EditText) this.getActivity().findViewById(R.id.etName);
final EditText etSurname = (EditText) this.getActivity().findViewById(R.id.etSurname);
final EditText etUsername = (EditText) this.getActivity().findViewById(R.id.etUsername);
final EditText etPassword = (EditText) this.getActivity().findViewById(R.id.etPassword);
final EditText etEmail = (EditText) this.getActivity().findViewById(R.id.etEmail);
final EditText etPhone = (EditText) this.getActivity().findViewById(R.id.etPhone);
final EditText etAge = (EditText) this.getActivity().findViewById(R.id.etAge);
final Button bRegister = (Button) this.getActivity().findViewById(R.id.bRegister);
此时错误v
bRegister.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final String name = etName.getText().toString();
final String surname = etSurname.getText().toString();
final String username = etUsername.getText().toString();
final String password = etPassword.getText().toString();
final String email = etEmail.getText().toString();
final int phone = Integer.parseInt(etPhone.getText().toString());
final int age = Integer.parseInt(etAge.getText().toString());
Response.Listener<String> responseListener = new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
boolean success = jsonResponse.getBoolean("success");
if(success){
Intent intent = new Intent(getActivity(), BlankFragment1.class);
BlankFragment2.this.startActivity(intent);
}
else {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); //create an error message
builder.setMessage("Register Failed")
.setNegativeButton("Retry",null) //click retry to retry registration
.create()
.show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
};
RegisterRequest registerRequest = new RegisterRequest(name, surname,age,username,password,email,phone,responseListener);
RequestQueue queue = Volley.newRequestQueue(getActivity());
queue.add(registerRequest);
}
});
return view;
}
bRegister.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
最终字符串名称=etName.getText().toString();
最后一个字符串姓氏=etnamame.getText().toString();
最终字符串username=etUsername.getText().toString();
最终字符串password=etPassword.getText().toString();
最终字符串email=etEmail.getText().toString();
final int phone=Integer.parseInt(etPhone.getText().toString());
final int age=Integer.parseInt(etAge.getText().toString());
Response.Listener responseListener=新的Response.Listener(){
@凌驾
公共void onResponse(字符串响应){
试一试{
JSONObject jsonResponse=新的JSONObject(响应);
boolean success=jsonResponse.getBoolean(“success”);
如果(成功){
Intent Intent=新的Intent(getActivity(),BlankFragment1.class);
空白片段2.这是一个开始的触觉(意图);
}
否则{
AlertDialog.Builder=新建AlertDialog.Builder(getActivity());//创建错误消息
builder.setMessage(“注册失败”)
.setNegativeButton(“重试”,null)//单击“重试”重试注册
.create()
.show();
}
}捕获(JSONException e){
e、 printStackTrace();
}
}
};
RegisterRequest RegisterRequest=新的RegisterRequest(姓名、姓氏、年龄、用户名、密码、电子邮件、电话、应答者);
RequestQueue=Volley.newRequestQueue(getActivity());
添加(registerRequest);
}
});
返回视图;
}
有什么帮助吗?您正在活动中查找视图,但需要在刚才为片段膨胀的视图中查找。对于所有的
findViewById
调用,将this.getActivity()
更改为view
,因此它将是view.findViewById
您应该从根视图/膨胀视图找到视图,而不是从getActivity()找到视图。因此,将这个.getActivity()更改为视图
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_blank_fragment2,container,false);
final EditText etName = (EditText) view.findViewById(R.id.etName);
final EditText etSurname = (EditText) view.findViewById(R.id.etSurname);
final EditText etUsername = (EditText) view.findViewById(R.id.etUsername);
final EditText etPassword = (EditText) view.findViewById(R.id.etPassword);
final EditText etEmail = (EditText) view.findViewById(R.id.etEmail);
final EditText etPhone = (EditText) view.findViewById(R.id.etPhone);
final EditText etAge = (EditText) view.findViewById(R.id.etAge);
final Button bRegister = (Button) view.findViewById(R.id.bRegister);
}
试试这个-
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_blank_fragment2,container,false);
final EditText etName = (EditText) view.findViewById(R.id.etName);
final EditText etSurname = (EditText) view.findViewById(R.id.etSurname);
final EditText etUsername = (EditText) view.findViewById(R.id.etUsername);
final EditText etPassword = (EditText) view.findViewById(R.id.etPassword);
final EditText etEmail = (EditText) view.findViewById(R.id.etEmail);
final EditText etPhone = (EditText) view.findViewById(R.id.etPhone);
final EditText etAge = (EditText) view.findViewById(R.id.etAge);
final Button bRegister = (Button) view.findViewById(R.id.bRegister);
第二段代码在哪里??我的意思是碎片生命周期的哪个功能??可能是您的
b注册表
不属于fragment\u blank\u fragment2
layoutuse view.findViewByDYIDY您正在活动中引用view(b注册表)
。在特定的视图上创建对象
而不是活动
。您正在调用final Button bRegister=(Button)this.getActivity().findViewById(R.id.bRegister)代码>在活动中,尝试在片段视图中调用它<代码>最终按钮b注册表=(按钮)视图.findViewById(R.id.b注册表)代码>是的,谢谢你它成功了!:)是的,谢谢你,成功了!:)是的,谢谢你,成功了!:)是的,谢谢你,成功了!:)