How to make a View object in Java in Android Studio? - android-studio

Question

In my program I have a class called GameView that is a View meaning it has Context and attrs attached to it. I have several non static methods and variables in this class that I would like to call in my MainActivity class but since it takes context and attrs I cant seem to figure out how to properly create an object in this situation. I have tried creating Context and SetAttribute variables in MainActivity to fill in the missing gaps but I think it makes it have a null exception and the app crashes as a result. I really need help on this since if I get this fixed I think my program will work really well. Below is a simplified version of my issue.
This is what I tried doing in the MainActivity to create object of GameView and to call the Method:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GameView gv = new GameView(context, attrs);
gv.myMethod();
This is what is in the GameView Class:
public class GameView extends View {
public GameView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
}
public void MyMethod() {
//stuff happens here
}

Answer 1

it is okay for me
public class GameView extends View {
public GameView(Context context) {
super(context);
}
public GameView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
}
public GameView(Context context, #Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public void MyMethod() {
//stuff happens here
}
}
in MainActivity in onCreate:
AttributeSet attrs = new AttributeSet(){
#Override
public int getAttributeCount() {
return 0;
}
#Override
public String getAttributeName(int index) {
return null;
}
#Override
public String getAttributeValue(int index) {
return null;
}
#Override
public String getAttributeValue(String namespace, String name) {
return null;
}
#Override
public String getPositionDescription() {
return null;
}
#Override
public int getAttributeNameResource(int index) {
return 0;
}
#Override
public int getAttributeListValue(String namespace, String attribute, String[] options, int defaultValue) {
return 0;
}
#Override
public boolean getAttributeBooleanValue(String namespace, String attribute, boolean defaultValue) {
return false;
}
#Override
public int getAttributeResourceValue(String namespace, String attribute, int defaultValue) {
return 0;
}
#Override
public int getAttributeIntValue(String namespace, String attribute, int defaultValue) {
return 0;
}
#Override
public int getAttributeUnsignedIntValue(String namespace, String attribute, int defaultValue) {
return 0;
}
#Override
public float getAttributeFloatValue(String namespace, String attribute, float defaultValue) {
return 0;
}
#Override
public int getAttributeListValue(int index, String[] options, int defaultValue) {
return 0;
}
#Override
public boolean getAttributeBooleanValue(int index, boolean defaultValue) {
return false;
}
#Override
public int getAttributeResourceValue(int index, int defaultValue) {
return 0;
}
#Override
public int getAttributeIntValue(int index, int defaultValue) {
return 0;
}
#Override
public int getAttributeUnsignedIntValue(int index, int defaultValue) {
return 0;
}
#Override
public float getAttributeFloatValue(int index, float defaultValue) {
return 0;
}
#Override
public String getIdAttribute() {
return null;
}
#Override
public String getClassAttribute() {
return null;
}
#Override
public int getIdAttributeResourceValue(int defaultValue) {
return 0;
}
#Override
public int getStyleAttribute() {
return 0;
}
};
GameView gv = new GameView(MainActivity.this,attrs);
gv.MyMethod();
other way create attrs use below link:
https://developer.android.com/training/custom-views/create-view#java