i new android app development ... doing create app adds 1 counter wen add button clicked , sub 1 wen subb button clicked . pls point out mistakes
startingpoint.java`
package vignesh.pandian.app; import android.os.bundle; import android.app.activity; import android.view.view; import android.widget.button; import android.widget.textview; public class startingpoint extends activity { int counter; button add, subb; textview displ; @override public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.activity_startingpoint); counter=0; add = (button) findviewbyid(r.id.add); subb =(button) findviewbyid(r.id.bsub); displ =(button) findviewbyid(r.id.tex); add.setonclicklistener(new view.onclicklistener() { public void onclick(view v) { // todo auto-generated method stub counter++; displ.settext("value "+counter); } }); subb.setonclicklistener(new view.onclicklistener() { public void onclick(view v) { // todo auto-generated method stub counter--; displ.settext("value is"+counter); } }); } }
activity_startingpoint.xml
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <button android:id="@+id/add" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_alignparentleft="true" android:layout_centervertical="true" android:text="add 1 " /> <textview android:id="@+id/my" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignparentbottom="true" android:layout_alignparentright="true" android:layout_marginbottom="15dp" android:text="vignesh's app !!!!" tools:context=".startingpoint" /> <textview android:id="@+id/tex" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_alignparentleft="true" android:layout_margintop="35dp" android:text="value is" android:textsize="35dp" tools:context=".startingpoint" /> <button android:id="@+id/bsub" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_alignparentleft="true" android:layout_below="@+id/add" android:layout_margintop="37dp" android:text="subract 1 " /> </relativelayout>
textview displ;
displ =(button) findviewbyid(r.id.tex);
this wrong, use this
displ =(textview) findviewbyid(r.id.tex);
disp1 textview object, not button object.
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