[android] 06_常见控件4-拖动条(SeekBar)

Android 4.0

常见控件4-拖动条(SeekBar)

拖动条(SeekBar)
SeekBar.getProgress()获取拖动条当前值
调用setOnSeekBarChangeListener()方法,处理拖动条值变化事件,把SeekBar.OnSeekBarChangeListener实例作为参数传入.
1、布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <SeekBar
        android:id="@+id/seekBar"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/seekBarButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="获取值" />
</LinearLayout>
2、核心代码:
package cn.zengfansheng.seekbar;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.Toast;
public class MainActivity extends Activity {
    protected static final String TAG = "MainActivity";
    private SeekBar seekBar;
    private Button seekBarButton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        seekBar = (SeekBar) this.findViewById(R.id.seekBar);
        seekBarButton = (Button) this.findViewById(R.id.seekBarButton);
        
        seekBar.setMax(100);
        seekBar.setProgress(50);
        // 监听seekbar状态的改变
        seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                // 1、开始拖拽,参数:seekbar表示当前在开始拖拽的SeekBar
                Log.i(TAG"onStartTrackingTouch():"+String.valueOf(seekBar.getProgress()));
            }
            
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress,
                // 2、拖拽过程中,参数1:当前正在拖拽的SeekBar,参数2:当前进度值,参数3:值变化是否通知
                    boolean fromUser) {
                Log.i(TAG"onProgressChanged():"+String.valueOf(progress) + ", " + String.valueOf(fromUser));
            }
            @Override
            public void onStopTrackingTouch(SeekBar seekBar) { 
                // 3、停止拖拽,参数:seekbar表示当前在停止拖拽的SeekBar
                Log.i(TAG,"onStopTrackingTouch():"+ String.valueOf(seekBar.getProgress()));
            }
        });
        
        seekBarButton.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this"当前seekbar的值:"+seekBar.getProgress(), 0).show();
            }
        });
    }
}
3、结果: