问题
I've been looking through the documentation for ProgressBar class and found these attributes:
- android:progressBarStyle
- android:progressBarStyleHorizontal
- android:progressBarStyleLarge
- android:progressBarStyleSmall
These four parameters are supposed to be a reference to some style as I take it. So the question is, what are these for? Style for the progress bar is set via android:style attribute and a reference to the global style attributes.
Documentation doesn't say anything helpful, searched the Web, found nothing.
回答1:
The four attributes that you mention can be applied to a ProgressBar's style like so:
style="?android:attr/progressBarStyleHorizontal"
The style constant android:progressBarStyleHorizontal is your typical incremental progress bar:
While the other three are varying sizes of the same circular progress bar:
style="?android:attr/progressBarStyleSmall"
style="?android:attr/progressBarStyle"
style="?android:attr/progressBarStyleLarge"
Update:
According to adamp's comments:
These are attributes of the theme that point at themed styles you can use for progress indicators...They are not attributes for ProgressBar itself.
回答2:
In case if someone is looking for full block of code
<ProgressBar
android:id="@+id/ProgressBar2"
style="?android:attr/progressBarStyleLarge"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
回答3:
The confusing part is that normally, you can define a default style for a widget (e.g. a button) like this:
<item name="android:buttonStyle">@style/Widget.AppCompat.Button.Colored</item>
All buttons will then by default have this style applied.
One would think that the progressBarStyle attribute would do the same for ProgressBar if doing this:
<item name="android:progressBarStyle">@style/Widget.AppCompat.ProgressBar</item>
But that is not the case, since progressBarStyle belongs to the ActionBar styleable.
来源：https://stackoverflow.com/questions/4288807/whats-the-meaning-of-androidprogressbarstyle-attribute-in-progressbar