Develop Reference

Android my App crash after set button disabled

My app crashes after I pressed a button.
My code:
<android.support.v7.widget.AppCompatButton
android:id="#+id/btn_print_trans"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:onClick="OnClickPrintSimpleApiTest"
android:text="PRINT"
android:textColor="#FFFFFF" />
and:
public void OnClickPrintSimpleApiTest(View view) {
final Button BTN_print = (Button) findViewById(R.id.btn_print_trans);
BTN_print.setBackgroundColor(Color.GREEN);
BTN_print.setEnabled(false);
}

Because the OP defined the onClick method OnClickPrintSimpleApiTest as an attribute in their xml layout file as:
android:onClick="OnClickPrintSimpleApiTest"
They do not need to get a reference to the Button using findViewById().
The Button view is passed to the OnClickPrintSimpleApiTest() method as the parameter "view". Therefore, simply do this:
public void OnClickPrintSimpleApiTest(View view) {
Button BTN_print = (Button) view
BTN_print.setBackgroundColor(Color.GREEN);
BTN_print.setEnabled(false);
}

One click listener for all views in a hierarchy?

Is there a way to set one click listener on all views in a hierarchy in one line? I believe we have to do something like the following:
<LinearLayout id="#+id/parent">
<TextView id="#+id/item1" />
<TextView id="#+id/item2" />
<TextView id="#+id/item3" />
</LinearLayout>
OnClickListener listener = ...;
View view = inflater.inflate(R.layout.the_above_layout);
view.setOnClickListener(listener);
view.findViewById(R.id.item1).setOnClickListener(listener);
view.findViewById(R.id.item2).setOnClickListener(listener);
view.findViewById(R.id.item3).setOnClickListener(listener);
...
But that's really a lot of code for a big view hierarchy. I could make a recursive function to do it, but is there something already available by android that does this for us?
Thanks

Android just implements the OnClickListener for you when you define the android:onClick="someMethod" attribute in xml.
<LinearLayout id="#+id/parent">
<TextView id="#+id/item1" android:onClick="myFancyMethod" />
<TextView id="#+id/item2" android:onClick="myFancyMethod" />
<TextView id="#+id/item3" android:onClick="myFancyMethod" />
</LinearLayout>
Then in your Activity just define a method like this.
public void myFancyMethod(View v) {
// does something very interesting
}
That is probably the fastest way to do it.

that is nice example i think so bcz i m also finding shortest way to clici refer this site for click listner
public class MyActivity extends Activity implements View.OnClickListener {
Button button1, button2, button3;
#Override
public void onCreate(Bundle bundle) {
super.onCreate();
...
button1 = (Button) findViewById(R.id.button1);
button2 = (Button) findViewById(R.id.button2);
button3 = (Button) findViewById(R.id.button3);
button1.setOnClickListener(this);
button2.setOnClickListener(this);
button3.setOnClickListener(this);
}
#Override
public void onClick(View v) {
switch(v.getId()) {
case R.id.button1:
// do stuff;
break;
case R.id.button2:
// do stuff;
break;
...
}
}

Well, this is the way add this line in your xml-
<TextView id="#+id/item1"
android:onClick="myMethod"
/>
And make sure you write this method in your class in which xml is used
public void myMethod(View v){
//content goes here
}
this will trigger your own methods

How to add a text under the image button in Android?

I want to add text under a image button, which are also clickable, and will be redirected to the same activity as the image button. basically it's like the app list in any android phone, e.g.

If you have your ImageButton declared in XML, then just put it into a LinearLayout which also contains a TextView and set the onClickListener on the LinearLayout. The structure would be like
<LinearLayout
... > <!-- This is the LinearLayout for the xml document -->
<!-- Some other layout code here if you please -->
<LinearLayout
android:id="#+id/linLayout"
... >
<ImageButton
... />
<TextView
... />
</LinearLayout>
</LinearLayout>
And then in your java:
LinearLayout layout = (LinearLayout)findViewById(R.id.linLayout);
layout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
If you're adding each ImageButton dynamically via java code, then it will still maintain the same structure. Let me know if I need to add anything.

setAlpha and do the below
<Button
android:id="#+id/comparePack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:onClick="compareButtonClick"
android:text="#string/compare"
android:drawableTop="#drawable/compare1edit"
android:gravity="left|center_vertical" />

if you want to create this king of list use gridview
and in getview method inflate customlayout with imageview and textview

Also you can set onClickListener to TextView
<!-- Some other layout code here if you please -->
<LinearLayout
android:id="#+id/linLayout"
... >
<ImageButton android:id="#+id/btn1"
... />
<TextView android:id="#+id/tv1"
... />
</LinearLayout>
java code:
ImageButton btn1 = (ImageButton) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myClick();
}
});
TextView tv1 = (TextView) findViewById(R.id.tv1);
tv1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myClick();
}
});

OnClick of Button more views should be added at runtime in the layout, but I am not able ot do that

I want to add views on click of button. My screen has a text view and an edit text and a "Add More" button. on the click of button another set of text view and edit text should get appended to the screen. I am also planning to add scroll view once the my screen grows longer.
My Code snippet is as follows
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
text.setText("hello how are you?"); //this is just an example, I may want to add lot more here.
linearLayout.addView(text);
setContentView(linearLayout);
}
I know I am missing something very basic but I do not know what is that. :(
Please help.

First of all, you need to initialize each TextView with a reference to the context. So, in your onClick, given that it is in MyActivity.java:
public void onClick(View v) {
TextView text = new TextView(this);
text.setLayoutParams(new LayoutParams(WRAP_CONTENT, WRAP_CONTENT); // Or what you decide
text.setText("Your text");
linearLayout.addView(text);
}
Second, given that you have a call to setContentView in onCreate which also adds your linearlayout to the view, you do not need to call setContentView(linearLayout) each time the button is clicked.

you should first create a new TextView and EditText add it to the linearLayout using linearLayout.addView(). No need to call setContentView() you probably already added it.

This One help you
In your XML file
<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"
android:id="#+id/myMainRelativeLayout"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<Button
android:id="#+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="47dp"
android:text="Add Button" />
And your Java file Like
public class MainActivity extends Activity implements
android.view.View.OnClickListener {
Button btnAdd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnAdd = (Button) findViewById(R.id.btnAdd);
btnAdd.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v.getId() == R.id.btnAdd) {
RelativeLayout rl = (RelativeLayout)findViewById(R.id.myMainRelativeLayout);
Button btn = new Button(this);
btn.setId(1234);
btn.setText("Add Button Runtime");
btn.setOnClickListener(this);
rl.addView(btn);
}
if(v.getId() == 1234)
{
Toast.makeText(getApplicationContext(), "This is Your New Button", Toast.LENGTH_LONG).show();
}
}
}
This one just example you can add any view like this

first click on linearlayout doesn flash background click color, it just flash for second and next click

I try to get the effect click background color for linear layout. I've set clickable to linear layout. and from the code also I've put the click listener the setBackgroundResource.
Here it is the xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout
android:id="#+id/llinsertmem"
android:clickable="true"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="50px">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="PUSH it"
/>
</LinearLayout>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
/>
</LinearLayout>
and the java code:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
linearInsertMem.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
v.setBackgroundResource(android.R.drawable.list_selector_background);
Toast.makeText(testdoank.this, "succeded", Toast.LENGTH_SHORT)
.show();
}
});
}
When first time click the clickable linearlayout, the toast text is displayed but the background color click effect doesn't. The flash background click color is only work from the second click.
any idea what the problem is?

Is not necessary do anything in JAVA code.
You can only add this as attribute:
android:background="#android:drawable/list_selector_background"
And it works for me (on Android 2.2 device)

After try and error, somehow it's work.
just put the setBackgroundResource also on the onCreate.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
linearInsertMem.setBackgroundResource(android.R.drawable.list_selector_background);
linearInsertMem.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
v.setBackgroundResource(android.R.drawable.list_selector_background);
Toast.makeText(testdoank.this, "succeded", Toast.LENGTH_SHORT)
.show();
}
});
}
Don't know the logic explanation. if you have a thought, please.

In the onClick method you are using v as the View which is passed, but that view may not be the LinearLayout which you want to change the background.
Thus you need to create a class level variable or a final varibale and pass the handle for the LineraLayout to the onClick method.
Remove/cut from onCreate:
linearInsertMem.setBackgroundResource(android.R.drawable.list_selector_background);
and paste it into onClick or change v. into linearInsertMem.
I think that Exlipse will then demand that linearInsertMem must be final like:
final LinearLayout linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
Or you can define this object above onCreate like this:
LinearLayout linearInsertMem;
then in onCreate you state:
linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
then onClick method will know exactly which view you want to change if you use linearInsertMem.setBackgroundResource...