Android的SeekBar和RateBar的使用-android学习之旅（三十二）

SeekBar简介

SeekBar允许用户拖动，进行调节经常用于音量调节等方面。

android：thumb设置drawable对象来表示拖动的物体。

setOnSeekBarChangeListener（）设置SeekBar的改变。

代码示例

package peng.liu.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.SeekBar;

public class MainActivity extends Activity {
private ImageView image;
private SeekBar seekBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
image = (ImageView) findViewById(R.id.image);
seekBar = (SeekBar) findViewById(R.id.seekBar);
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
image.setAlpha(i);
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {

}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {

}
});
}
}

布局代码

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:orientation="vertical">

<ImageView
android:layout_width="fill_parent"
android:layout_height="240px"
android:id="@+id/image"
android:src="@drawable/ic_launcher"
android:scaleType="fitXY"/>
<SeekBar
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/seekBar"
android:max="255"
android:progress="255"
/>
</LinearLayout>

效果图

RatingBar简介

RatingBar是一个星级评分条，它和SeekBar有着相同的父类AbsSeekBar，因此属性相似。

RatingBar属性

代码示例

package peng.liu.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.SeekBar;

public class MainActivity extends Activity {
private ImageView image;
private RatingBar ratingBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
image = (ImageView) findViewById(R.id.image);
ratingBar = (RatingBar) findViewById(R.id.ratingBar);
ratingBar.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {
@Override
public void onRatingChanged(RatingBar ratingBar, float v, boolean b) {
image.setAlpha(v*255/5);
}
});
}
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:orientation="vertical">

<ImageView
android:layout_width="fill_parent"
android:layout_height="240px"
android:id="@+id/image"
android:src="@drawable/ic_launcher"
android:scaleType="fitXY"/>
<RatingBar
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/ratingBar"
android:max="255"
android:progress="255"
android:numStars="5"
android:stepSize="0.5"/>
</LinearLayout>

效果图