dpi value of default “large”, “medium” and “small”

问题:

Does the documentation ( or anyone) talks about the dpi values of the default

• Large TextView {android:textAppearance="?android:attr/textAppearanceLarge"}
• Medium TextView {android:textAppearance="?android:attr/textAppearanceMedium"}
• Small TextView { android:textAppearance="?android:attr/textAppearanceSmall"}

widgets in the SDK ?

To put it in another way, can we replicate the appearance of these text views without using the android:textAppearance attribute?

回答1:

See in the android sdk directory.

In \platforms\android-X\data\res\values\themes.xml:

    <item name="textAppearanceLarge">@android:style/TextAppearance.Large</item>
    <item name="textAppearanceMedium">@android:style/TextAppearance.Medium</item>
    <item name="textAppearanceSmall">@android:style/TextAppearance.Small</item>

In \platforms\android-X\data\res\values\styles.xml:

<style name="TextAppearance.Large">
    <item name="android:textSize">22sp</item>
</style>

<style name="TextAppearance.Medium">
    <item name="android:textSize">18sp</item>
</style>

<style name="TextAppearance.Small">
    <item name="android:textSize">14sp</item>
    <item name="android:textColor">?textColorSecondary</item>
</style>

TextAppearance.Large means style is inheriting from TextAppearance style, you have to trace it also if you want to see full definition of a style.

Link: http://developer.android.com/design/style/typography.html

回答2:

To put it in another way, can we replicate the appearance of these text views without using the android:textAppearance attribute?

Like biegleux already said:

• small represents 14sp
• medium represents 18sp
• large represents 22sp

If you want to use the small, medium or large value on any text in your Android app, you can just create a dimens.xml file in your values folder and define the text size there with the following 3 lines:

<dimen name="text_size_small">14sp</dimen>
<dimen name="text_size_medium">18sp</dimen>
<dimen name="text_size_large">22sp</dimen>

Here is an example for a TextView with large text from the dimens.xml file:

<TextView
  android:id="@+id/hello_world"
  android:text="hello world"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textSize="@dimen/text_size_large"/>

回答3:

Programmatically, you could use:

textView.setTextAppearance(android.R.style.TextAppearance_Large);