初识SeekBar

SeekBar拖动条，是Progress的间接子类

 <SeekBar
             android:id="@+id/seekBar1"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:progress="30"
             //Draws the thumb on a seekbar.
             android:thumb="@drawable/peasy" />

SeekBar事件，被拉动时，onProgressChanged会一直被触发

 public void showSeekBar() {
         seekBar = (SeekBar) findViewById(R.id.seekBar1);
         seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

             @Override
             public void onStopTrackingTouch(SeekBar seekBar) {
                 // TODO Auto-generated method stub
                 Log.i(TAG, "onStopTrackingTouch");
                 Toast.makeText(FormActivity.this,
                         "current level is " + seekBar.getProgress(), 3000)
                         .show();
             }

             @Override
             public void onStartTrackingTouch(SeekBar seekBar) {
                 // TODO Auto-generated method stub
                 Log.i(TAG, "onStartTrackingTouch");

             }

             @Override
             public void onProgressChanged(SeekBar seekBar, int progress,
                     boolean fromUser) {
                 // TODO Auto-generated method stub
                 Log.i(TAG, "onProgressChanged");

             }
         });
     }