This is so simple
1. Go to your Google + account (https://plus.google.com/).
2. Click on the Profile icon on the Left.
3. If you look at the URL in the address bar, it should look something like this:
https://plus.google.com/104653270154306099169/posts
4. The long numerical string in the URL is your Google+ ID. Here is CoderzHeaven’s from the URL above:
104653270154306099169/
We will go straight to the code.
package com.coderzheaven.seterror;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn =(Button)findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
EditText edittext =(EditText)findViewById(R.id.editText1);
if(edittext.getText().length()==0){
edittext.setError("Field cannot be left blank.");
}
}
});
}
}
This is the layout containing the EditText and the Button.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<EditText
android:id="@+id/editText1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/editText1"
android:text="Check" />
</RelativeLayout>
