TextView Attributes

You can use XML attributes for a TextView to control:

• Where the TextView is positioned in a layout (like any other view)

• How the TextView itself appears, such as with a background color

• What the text looks like within the TextView, such as the initial text and its style, size, and color

For example, to set the width, height, and initial text value of the view:

<TextView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="Hello World!"
   <!-- more attributes -->
/>

You can extract the text string into a string resource (perhaps called hello_world) that's easier to maintain for multiple-language versions of the app, or if you need to change the string in the future. After extracting the string, use the string resource name with @string/ to specify the text:

<TextView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="@string/hello_world"
   <!-- more attributes -->
/>

In addition to android:layout_width and android:layout_height (which are required for a TextView), the most often used attributes with TextView are the following:

• ​android:text: Set the text to display.

• ​android:textColor: Set the color of the text. You can set the attribute to a color value, a predefined resource, or a theme. Color resources and themes are described in other chapters.

• ​android:textAppearance: The appearance of the text, including its color, typeface, style, and size. You set this attribute to a predefined style resource or theme that already defines these values.

• ​android:textSize: Set the text size (if not already set by android:textAppearance). Use sp (scaled-pixel) sizes such as 20sp or 14.5sp, or set the attribute to a predefined resource or theme.

• ​android:textStyle: Set the text style (if not already set by android:textAppearance). Use normal, bold, italic, or bold|italic.

• ​android:typeface: Set the text typeface (if not already set by android:textAppearance). Use normal, sans, serif, or monospace.

• ​android:lineSpacingExtra: Set extra spacing between lines of text. Use sp (scaled-pixel) or dp (device-independent pixel) sizes, or set the attribute to a predefined resource or theme.

• ​android:autoLink: Controls whether links such as URLs and email addresses are automatically found and converted to clickable (touchable) links.

Use one of the following with android:autoLink:

• none: Match no patterns (default).

• web: Match web URLs.

• email: Match email addresses.

• phone: Match phone numbers.

• map: Match map addresses.

• all: Match all patterns (equivalent to web|email|phone|map).

For example, to set the attribute to match web URLs, use android:autoLink="web".

Referring to a TextView in code

To refer to a TextView in your Java code, use its resource id. For example, to update a TextView with new text, you would:

1. Find the TextView and assign it to a variable. You use the findViewById() method of the View class, and refer to the view you want to find using this format:

    R.id.view_id

   In which view_id is the resource identifier for the view (such as show_count) :

   mShowCount = (TextView) findViewById(R.id.show_count);

2. After retrieving the View as a TextView member variable, you can then set the text to new text (in this case, mCount_text) using the setText() method of the TextView class:

    mShowCount.setText(mCount_text)