Android SeekBar例子

Android SeekBar 是一种带有可拖动拇指的进度条。最终用户可以拖动拇指左右移动歌曲、文件下载等的进度。

SeekBar.OnSeekBarChangeListener接口提供了用于seek bar的事件处理的方法。

Android SeekBar和RatingBar类都是AbsSeekBar的子类。

Android SeekBar示例

activity_main.xml

从工具栏中拖动seek bar，现在activity_main.xml的代码如下:

文件: activity_main.xml

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:app="http://schemas.android.com/apk/res-auto"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="example.javatpoint.com.seekbar.MainActivity">  


    <SeekBar  
        android:id="@+id/seekBar"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="372dp"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent" />  
</android.support.constraint.ConstraintLayout>

Activity类

下面我们来看一下展示seek bar和执行事件处理的Activity类。

文件: MainActivity.java

“`java
package example.javatpoint.com.seekbar;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.SeekBar;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
SeekBar seekBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

<pre><code> seekBar=(SeekBar)findViewById(R.id.seekBar);
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
Toast.makeText(getApplicationContext(),"seekbar progress: "+progress, Toast.LENGTH_SHORT).show();
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
Toast.makeText(getApplicationContext(),"seekbar touch started!", Toast.LENGTH_SHORT).show();
}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
Toast.makeText(getApplicationContext(),"seekbar touch stopped!", Toast.LENGTH_SHORT).show();
}
});
}
</code></pre>

}
“““

输出:

Android SeekBar例子