actually I am bit confused on some thing which is working in one scenario very well but in other scenario that is not working fine so I am here to explain my problem to identify the wrong move made by me, if any on will identify the problem please mention it. thank you.
working fine:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.distance_demo_button).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, ListViewClass.class);
intent.putExtra(ListViewClass.EXTRAS_TARGET_ACTIVITY, Distance.class.getName());
startActivity(intent);
}
});
NOt working fine:
scan = (Button) view.findViewById(R.id.scan);
scan.setOnClickListener(startListener);
}
//Create an anonymous implementation of OnClickListener
private OnClickListener startListener = new OnClickListener() {
public void onClick(View v) {
Toast.makeText(view.getContext(),"Scanning", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this, ListViewClass.class);
intent.putExtra(ListViewClass.EXTRAS_TARGET_ACTIVITY, Distance.class.getName());
startActivity(intent);
}
}
now the problem is in this line
Intent intent = new Intent(MainActivity.this, ListViewClass.class);
when I use this line in this scenario it shows me error on this line:
Error: 'The constructor Intent(MainActivity, Class<ListViewClass>) is undefined' please mention my problem if you are well aware of it.
use a global context variable glaboaly and use it.
Context myContext;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
myContext = MyActivity.this;
}
and use myContext insted of MainActivity.this.
Im not sure whether it solve the problem, just try it out
When your calling Intent intent = new Intent(MainActivity.this, ListViewClass.class); inside MainActivity class. It will work fine. But when your not in Context of MainActivity class. i.e move to other class. This error will occur.
If you want to rectify, You can follow #jithu method. Otherwise store the context in Application class. And use it in anywhere.
In the first case you are overriding the method onClick().
If you override the method it's like you are declaring the function in your activity class.
This is the reason that you can call MainActivity.this
In the second case you are implementing the abstract method onClick(). You can't call MainActivity.this because your "MainActivity.this" is referencing to the current context and this isn't accessible from OnClickListener.class.
Related
I'm new to android studio and i have a problem when I'm trying to jump to a new activity, so when the line is:
public class signup_activity extends AppCompatActivity {
ImageButton logupButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_signup_activity);
logupButton = findViewById(R.id.signuparrow);
logupButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, signup_activity.class);
startActivity(intent);
}
});
}}
I get the error:
'com.example.myapplication.MainActivity' is not an enclosing class
and i so a couple of of people advising to chane the intent to this instead of MainActivity.this
but when im changing to this i get the error:
Cannot resolve constructor 'intent'
Intent intent = new Intent(MainActivity.this, signup_activity.class);
Several things:
First, the first param of Intent() constructor is a context. Since you are on signup_activity you need to do signup_activity.this to use it as a context.
I'd assume you want to go to MainActivity, so your second param should be MainActivity.class. It seems you got the order altered there.
you are in signup_activity and when use Intent in fisrt part you should call the current contex to jump to other activity.
so you should replace
Intent intent = new Intent(signup_activity.this, MainActivity.class);
if you want to jump to signup_activity you can call intent from MainActivity.
I'm a little bit new using Butterknife and I'm having a problem. I want click on a textview and the open another activity. I know how to do that without using Butterknife, but this is what I did so far:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
ButterKnife.bind(this);
}
#OnClick(R.id.tv_forgot_pass)
void forgotPassClick(){
Context mContext = LoginActivity.this;
Class nextActivity = ForgotPasswordActivity.class;
Intent mIntent = new Intent(mContext, nextActivity);
startActivity(mIntent);
finish();
}
}
My problem right now is I don't know how to use my onClick method, because if I put the that method inside the onCreate, the activity will open the next activity immediately. I tried to use tv_forgot_pass.setOnClickListener and didn't work. And also doesn't work in the xml because the method doesnt have a View as parameter.
It is okey what Im doing? or there is another way to set a clicklistner with Butterknife?
I'm going to explain why is not duplicated with this question
First, they are using and old version of Butterknife, I'm using the 8.8.1 version and the "duplicate question" is using 6.1.0. My version doesnt support InjectView(it's Bind now). Second, my question talks about click on a TextView, the other question talks about click on a button. It's similar but not the equal. And the most important, I read the "duplicate question" like an hour ago, before I asked my question and because I didn't find a solution to my problem I decided to post my question.
java.lang.IllegalStateException: Could not find method forgotPassClick(View) in a parent or ancestor
Context for android:onClick attribute defined on view class
android.support.v7.widget.AppCompatTextView with id 'tv_forgot_pass'
Logcat showing IllegalStateException
Signals that a method has been invoked at an illegal or inappropriate
time. In other words, the Java environment or Java application is not
in an appropriate state for the requested operation.
You should Use AppCompatTextView instead of
TextView.
Remove android:onClick="forgotPassClick" from XML.
XML
<android.support.v7.widget.AppCompatTextView
android:id="#+id/tv_forgot_pass"
android:focusable="true"
.... />
Then
#OnClick(R.id.tv_forgot_pass)
void forgotPassClick(){
Context mContext = LoginActivity.this;
Intent mIntent = new Intent(mContext, ForgotPasswordActivity.class);
startActivity(mIntent);
finish();
}
}
For onClick
#OnClick(R.id.tv_forgot_pass)
public void onForgotPassClick(View view) {
Context mContext = LoginActivity.this;
Intent mIntent = new Intent(mContext, ForgotPasswordActivity.class);
startActivity(mIntent);
finish();
}
Whatever you are doing is right.
#OnClick(R.id.tv_forgot_pass)
void forgotPassClick(){
Context mContext = LoginActivity.this;
Class nextActivity = ForgotPasswordActivity.class;
Intent mIntent = new Intent(mContext, nextActivity);
startActivity(mIntent);
finish();
}
above code will be executed when you will click on tv_forgot_pass.
make some change.
first bind text view as local of class like below ..
#BindView(R.id.myTextView)
TextView myTextView;
then after onCreate method bind butter knife like below ..
ButterKnife.bind(this);
then after apply click event like below ..
#OnClick(R.id.myTextView)
private void goNextActivity(){
Intent mIntent = new Intent(this, ForgotPasswordActivity.class);
startActivity(mIntent);
finish();
}
and both activity define in android manifest file.
Use #Bind before oncreate will work fine
public class Login extends AppCompatActivity {
#Bind(R.id.tv_forgot_pass)
Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
ButterKnife.bind(this);
}
#OnClick(R.id.tv_forgot_pass)
public void forgotPassClick(){
Context mContext = LoginActivity.this;
Class nextActivity = ForgotPasswordActivity.class;
Intent mIntent = new Intent(mContext, nextActivity);
startActivity(mIntent);
finish();
}
}
Good evening Stack !
I have started to learn Android development as a hobby and I am now trying to develop my first "real" application (I have made already only five simple applications from books).
In this application, I have two buttons that will "create" the same Activity but by using two different objects from the same base class, hence allowing me to customize the behavior of the application depending on the button that was clicked.
However, when I am trying to create the Intent instance, my application crashes.
Here is the code of the base Activity class
public class BaseDictionnaryActivity extends Activity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.basedictionnary);
}
public void onDestroy()
{
super.onDestroy();
}
}
and here is the code that crashes. The line is the one creating the Intent object.
public class DictionnaryActivity extends Activity
{
private BaseDictionnaryActivity jlpt1;
private BaseDictionnaryActivity jlpt2;
private Button btjlpt1 = null;
private Button btjlpt2 = null;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.dictionnary);
jlpt2 = new BaseDictionnaryActivity();
jlpt1 = new BaseDictionnaryActivity();
btJLPT1 = (Button)findViewById(R.id.jlpt1);
btJLPT1.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
Intent myIntent = new Intent(DictionnaryActivity.this,
jlpt1.getClass());
jlpt1.this.startActivity(myIntent);
}
});
btJLPT2 = (Button)findViewById(R.id.jlpt2);
btJLPT2.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
Intent myIntent = new Intent(DictionnaryActivity.this,
jlpt2.getClass());
jlpt2.this.startActivity(myIntent);
}
});
}
public void onDestroy()
{
super.onDestroy();
}
}
Thank you for your help !
Just to make correction,
Intent myIntent = new Intent(DictionnaryActivity.this,
jlpt1.getClass());
In this the second argument must be, your target activity BaseDictionnaryActivity.class
So, it looks something like,
Intent myIntent = new Intent(DictionnaryActivity.this,
BaseDictionnaryActivity.class);
startActivity(myIntent);
Also please make sure there will be entry of BaseDictionnaryActivity in your Application's manifest file,
Which is look like,
<activity android:name=".BaseDictionnaryActivity"
....>
</activity>
Maybe:
Intent myIntent = new Intent(DictionnaryActivity.this,
BaseDictionnaryActivity.class);
startActivity(myIntent);
change this
Intent myIntent = new Intent(DictionnaryActivity.this,
NextActivity.class);
Intent myIntent = new Intent(DictionnaryActivity.this,
jlpt2.class);
^^^^^^^^^^^^
You need to provide next activity .class in second argument of Intent.
Replace jlpt1.getClass() with NameOfClassToBeLaunched.class
Also this is bad practice to create Activity instances in other activities.
Any help will be highly appreciated. I am using a ImageButton in each row of a ListView. When user presses the Button, I need to fire another activity. I have written the code
viewHolder.editWordButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(view.getContext(), EditTextClass.class);
startActivity(i);
}
});
But it does not identify function startActivity(i)?
You do realize that startActivity(..) is not a method of an OnClickListener? Where does startActivity(...) come from? Why it comes from Context. So knowing this, how can you start the activity, what do you need? CONTEXT.
because there is no such function in this class OnClickListener. Try calling it from context, or if it will not work from applicationContext
I am trying to build a char using the library from achartengine (http://www.achartengine.org/). So i try to run SalesGrowthChart.java on my own aplication so when someone clicks on a button it will show him the chart .
This is my code :
private IChart[] mCharts = new IChart[]{new generatedchart()};
And i try to generate it like this
bt.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), generatedchart.class);
myIntent=mCharts[0].execute(this);
}
});
But this won't work. How can i make it to work.Hope you understand what i am saying.
This is the error :
The method execute(Context) in the type IChart is not applicable for the arguments (new View.OnClickListener(){})
Your problem is that the "this" mentioned inside that method refers to a view (which is what you are creating at that point.)
The method execute needs a Context, so you need to get the context in a different manner.
You should try getting the context like this:
YourActivityName.this
Which in your code would be like:
bt.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), generatedchart.class);
myIntent=mCharts[0].execute(YourActivityName.this);
}
});
When you are calling this within execute(), it is referring to the OnClickListener class because of the dynamic class declaration. Try using getApplicationContext() instead of this.