如何在Android的快餐栏中创建渐变？

Question

I know I can set the snackbar's background by using sbView.setBackgroundColor(Color.XX); , however, if we need to add gradient to the color instead of a single color background. What should I do? Seems no API for that.

Answer 1

The Snackbar does not allow you to set a custom layout. However, as Primoz990 suggested you can get the Snackbar's View. The getView function returns the Snackbar.SnackbarLayout, which is a horizontal LinearLayout object whose children are a TextView and a Button. To add your own View to the Snackbar, you just need to hide the TextView, and add your View to the Snackbar.SnackbarLayout.

 // Create the Snackbar Snackbar      
 snackbar = Snackbar.make(containerLayout, "", Snackbar.LENGTH_LONG); 
 // Get the Snackbar's layout view 
 Snackbar.SnackbarLayout layout = (Snackbar.SnackbarLayout) snackbar.getView(); 
 // Hide the text 
 TextView textView = (TextView) layout.findViewById(android.support.design.R.id.snackbar_text); 
 textView.setVisibility(View.INVISIBLE); 
 // Inflate our custom view 
 View snackView = mInflater.inflate(R.layout.my_snackbar, null); 
 // Configure the view 
 ImageView imageView = (ImageView)       
 snackView.findViewById(R.id.image); 
 imageView.setImageBitmap(image); 
 TextView textViewTop = (TextView) 
 snackView.findViewById(R.id.text); 
 textViewTop.setText(text); 
 textViewTop.setTextColor(Color.WHITE); 
 // Add the view to the Snackbar's layout 
 layout.addView(snackView, 0); 
 // Show the Snackbar 
 snackbar.show();

In this way you can set custom layout to snackbar.

Now you can set gradient in such a way:

Create a my_gradient.xml

 <?xml version="1.0" encoding="utf-8"?> 
 <shape 
       xmlns:android="http://schemas.android.com/apk/res/android"> 
      <gradient 
           android:type="linear" 
           android:angle="0" 
           android:startColor="#f6ee19" 
           android:endColor="#115ede" /> 
</shape>

Now apply to you custom layout as:

 android:background="@drawable/my_gradient"

Answer 2

You may need to define a background as a shape in drawable folder and give it appropriate gradient as you wish lets assume this one:

Lets call it snackbar_background.xml then:

<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
    <gradient
        android:startColor="#000000"
        android:centerColor="#5b5b5b"
        android:endColor="#000000"
        android:angle="0" />
</shape>

You can explore how to make a shape in android and add a gradient to it.

Then for your snackbar :

View snackView=snackbar.getView();
snackView.setBackgroundResource(R.drawable.snackbar_background);

And it will work fine from there.