android.R.color.transparent not fully transparent - android

In my application, I apply the transparent background to my ListView's CustomListItem at runtime. For that I use, convertView.setBackgroundColor(android.R.color.transparent);. It works and shows transparency. But that is not fully transparent as there is some kind of shade to the background. I also tried putting my own transparent color with the values #80000000 and #00000000 but the result is worse. What can I do to get the fully transparent color?


Set this attribute to your listview in xml file
android:background="#android:color/transparent"
and also apply the transparent background to your ListView's CustomListItem at runtime.
For that you have use,
convertView.setBackgroundColor(Color.TRANSPARENT);
Thanks


android.R.color.transparent is a resource id (referring to a transparent color definition) - View.setBackgroundColor(int) expects an actual int color.
Use View.setBackgroundResource(int) instead, which will load the actual color from resources.


convertView.setBackgroundColor(Color.argb(0, 0, 0, 0));
OR
convertView.setBackgroundColor(Color.parseColor("#00000000"));


Use this from now in your xml's files when you want transparency in your views:
android:background="#null"
You are going to get a better performance.


Try:
convertView.setBackgroundColor(Color.argb(0, 0, 0, 0));

Related

MPAndroidChart - Set a background image [duplicate]

I'm using the amazing library MPAndroidChart. It works like a charm, except when I'm trying to change the background color of the BarData. Default color is white, and I want to change it to Transparent.
I've tried this :
Paint p1 = mChart.getPaint(Chart.PAINT_GRID_BACKGROUND);
p1.setColor(Color.RED);
and this:
<com.github.mikephil.charting.charts.BarChart
android:id="#+id/chart1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/transparent"/>
... but it seems that doesnt works.
Any ideas ?
Thanks =)

Since release v1.6.5, the background of the Chart is transparent by default. Meaning, that everything in the background (chart background, other Views, etc.) that is not overlayed by data drawn into the Chart, will be visible.
If you want to change the background (color, or maybe drawable), you can either do that by changing the chart-background
in .xml (android:background="...")
by calling setBackgroundColor(...) or setBackgroundResource(...)
Another way could be to change the background of the parent layout that contains the Chart.

Code to change Background color:
chart.setBackgroundColor(Color.TRANSPARENT); //set whatever color you prefer
chart.setDrawGridBackground(false);// this is a must

if you want to Change Whole Screen Background Color
Barchart chart;
chart.setBackgroundColor(Color.rgb(0, 0, 0));//Set as a black
chart.setDrawGridBackground(false);//set this to true to draw the grid background, false if not
Happy to help Thanks

So, after some research, I've found that it's not possible yet: https://github.com/PhilJay/MPAndroidChart/issues/53
Hope It will be possible soon ! =)

How to change chart background with MPAndroidChart library?

I'm using the amazing library MPAndroidChart. It works like a charm, except when I'm trying to change the background color of the BarData. Default color is white, and I want to change it to Transparent.
I've tried this :
Paint p1 = mChart.getPaint(Chart.PAINT_GRID_BACKGROUND);
p1.setColor(Color.RED);
and this:
<com.github.mikephil.charting.charts.BarChart
android:id="#+id/chart1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/transparent"/>
... but it seems that doesnt works.
Any ideas ?
Thanks =)

Since release v1.6.5, the background of the Chart is transparent by default. Meaning, that everything in the background (chart background, other Views, etc.) that is not overlayed by data drawn into the Chart, will be visible.
If you want to change the background (color, or maybe drawable), you can either do that by changing the chart-background
in .xml (android:background="...")
by calling setBackgroundColor(...) or setBackgroundResource(...)
Another way could be to change the background of the parent layout that contains the Chart.

Code to change Background color:
chart.setBackgroundColor(Color.TRANSPARENT); //set whatever color you prefer
chart.setDrawGridBackground(false);// this is a must

if you want to Change Whole Screen Background Color
Barchart chart;
chart.setBackgroundColor(Color.rgb(0, 0, 0));//Set as a black
chart.setDrawGridBackground(false);//set this to true to draw the grid background, false if not
Happy to help Thanks

So, after some research, I've found that it's not possible yet: https://github.com/PhilJay/MPAndroidChart/issues/53
Hope It will be possible soon ! =)

How may I add a faded colour effect (screenshot shown)

Hey I would like to know how i can added such a faded color effect to my layout any help is appreciated. An example here:
Thanks

You can create a Shape Drawable with your desired gradient and set it as a background for your information view at the bottom

You can use setAlpha() method to adjust alpha level for your views and thereby get a faded effect.For handling this in xml you can use android:alpha attribute for your view.

android change view's background color when state changes

how to use color state list for background?
I know android:background="#drawable/drawable_selector", but android:background="#color/color_selector" will cause exceptions.
but android:background="#FFFFFF" works again, can anyone explains why?
now i want to change a layout's background color(not a drawable) when it's pressed,
how to do it?

dynamically you can change like this. Use this if it is useful for you -
textView.setBackgroundColor(Color.parseColor(getResources().getString(R.string.red)));

put the color in res/values/colors.xml,
like #FFFFFF,
and then create a drawable xml in drawable directory,
,that is ok.

How to set background color of a View

I'm trying to set the background color of a View (in this case a Button).
I use this code:
// set the background to green
v.setBackgroundColor(0x0000FF00 );
v.invalidate();
It causes the Button to disappear from the screen. What am I doing wrong, and what is the correct way to change the background color on any View?
Thanks.

You made your button transparent. The first byte is the alpha.
Try v.setBackgroundColor(0xFF00FF00);

When you call setBackgoundColor it overwrites/removes any existing background resource, including any borders, corners, padding, etc.
What you want to do is change the color of the existing background resource...
View v;
v.getBackground().setColorFilter(Color.parseColor("#00ff00"), PorterDuff.Mode.DARKEN);
Experiment with PorterDuff.Mode.* for different effects.

Several choices to do this...
Set background to green:
v.setBackgroundColor(0x00FF00);
Set background to green with Alpha:
v.setBackgroundColor(0xFF00FF00);
Set background to green with Color.GREEN constant:
v.setBackgroundColor(Color.GREEN);
Set background to green defining in Colors.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="myGreen">#00FF00</color>
<color name="myGreenWithAlpha">#FF00FF00</color>
</resources>
and using:
v.setBackgroundResource(R.color.myGreen);
and:
v.setBackgroundResource(R.color.myGreenWithAlpha);
or the longer winded:
v.setBackgroundColor(ContextCompat.getColor(getContext(), R.color.myGreen));
and:
v.setBackgroundColor(ContextCompat.getColor(getContext(), R.color.myGreenWithAlpha));

You can set the hex-color to any resource with:
View.setBackgroundColor(Color.parseColor("#e7eecc"));

// set the background to green
v.setBackgroundColor(0x0000FF00 );
v.invalidate();
The code does not set the button to green. Instead, it makes the button totally invisible.
Explanation: the hex value of the color is wrong. With an Alpha value of zero, the color will be invisible.
The correct hex value is 0xFF00FF00 for full opacity green. Any Alpha value between 00 and FF would cause transparency.

For setting the first color to be seen on screen, you can also do it in the relevant layout.xml (better design) by adding this property to the relevant View:
android:background="#FF00FF00"

and what is the correct way to change
the background color on any View?
On any View? What you have is correct, though you should drop the invalidate() call.
However, some Views already have backgrounds. A Button, for example, already has a background: the face of the button itself. This background is a StateListDrawable, which you can find in android-2.1/data/res/drawable/btn_default.xml in your Android SDK installation. That, in turn, refers to a bunch of nine-patch bitmap images, available in multiple densities. You would need to clone and modify all of that to accomplish your green goals.
In short, you will be better served finding another UI pattern rather than attempting to change the background of a Button.

try to add:
setBackgroundColor(Color.parseColor("#FF0000"));

I use at API min 16 , target 23
Button WeekDoneButton = (Button) viewWeeklyTimetable.findViewById(R.id.week_done_button);
WeekDoneButton.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.colorAccent));

mButton.setBackgroundColor(getResources().getColor(R.color.myColor));

You can simple use :
view.setBackgroundColor(Color.parseColor("#FFFFFF"));

You can simple use :
view.setBackgroundColor(Color.rgb(0, 198, 255));

This question talks about changing the background color of a view. In one of the answers, the person explains how to change the background color during runtime. Obviously you are going to look into how to modify other objects on the screen, but this should give you a good start by at least allowing you to modify the background color of the view on button click.

Stating with Android 6 use ContextCompact
view.setBackgroundColor( ContextCompat.getColor(this, R.color.your_color));

This works for me
v.getBackground().setTint(Color.parseColor("#212121"));
That way only changes the color of the background without change the background itself. This is usefull for example if you have a background with rounded corners.

In kotlin you could do it like this:
val backgroundColor = R.color.whatever_color_you_like
view.setBackgroundColor(getColorCompat(backgroundColor))
Where getColorCompat() is an extension function:
/**
* Extension method to provide simpler access to {#link ContextCompat#getColor(int)}.
*/
fun Context.getColorCompat(color: Int) = ContextCompat.getColor(this, color)

view.setBackgroundColor(R.color.primaryColor);
Adds color to previous color value, so i have a different color.
What works for me is :
view.setBackgroundResource(R.color.primaryColor);

Let suppose we have a primary color in values=>colors.xml as:
<resources>
<color name="primary">#FDD835</color>
</resources>
so if we want to use our custom color into setBackgroundColor(#ColorInt int Color) then we just need an annotation #SuppressLint("ResourceAsColor") with constructor/method which will be used as:
#SuppressLint("ResourceAsColor")
public _LinearLayout(Context context) {
super(context);
// Formatting our layout : )
super.setBackgroundColor(R.color.primary);
....
}

You must pass an int in the argument.
First Example:
view.setBackgroundColor(-500136)
Second Example:
int colorId = R.color.green;
view.setBackgroundResource(colorId);

This should work fine: v.setBackgroundColor(0xFF00FF00);

I tried all the above ways. But I havent achieve what i need. Here is my try.
If you are using hexcode for color and want to set the color as background of image, then this is the kotlin code.
val bitmap = Bitmap.createBitmap(30, 30, Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
val colorCode = "#ffffff"
canvas.drawColor(Color.parseColor(colorCode))
mImageViewLogo.setImageBitmap(bitmap)

When calling setBackgroundColor on a view you need to set the alpha value to a non-zero value (e.g. 0xFF), otherwise the color will not show up.
TextView tv = (TextView)findViewById(R.id.myTextview);
int rgb = 0xF05922; // Orange
tv.setBackgroundColor(0xFF000000|rgb); // Use bitwise OR to add alpha to RGB value

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