Android Webview缩放控件

Question

我想控制android webview的放大和缩小，就像pinchzoom一样使用探索栏。我该怎么做呢？Webview文本缩放控制是从API级别14给出的。但我必须从较低的API级别(8)支持它。

Answer 1

简单来说，通过使用webView对象，

webView.getSettings().setBuiltInZoomControls(true);

Answer 2

XML：

<SeekBar
android:id="@+id/zoombar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:max="20"
android:progress="0"/>

活动类：

private SeekBar myZoomBar;

@Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  ....
  myZoomBar = (SeekBar)findViewById(R.id.zoombar);
  myZoomBar.setMax (100);
  ....
  myZoomBar.setOnSeekBarChangeListener(myZoomBarOnSeekBarChangeListener);

}

private SeekBar.OnSeekBarChangeListener myZoomBarOnSeekBarChangeListener =
new SeekBar.OnSeekBarChangeListener(){
    public void onProgressChanged(SeekBar seekBar, int progress,
     boolean fromUser) {
     webView.setInitialScale(progress); //For initial Zoom
     //You can use `setScaleX()` ans `setScaleY()` but you will have to choose proper scale value for `X` and `Y` 
    }

    public void onStartTrackingTouch(SeekBar seekBar) {
    // TODO Auto-generated method stub

    }

    public void onStopTrackingTouch(SeekBar seekBar) {
    // TODO Auto-generated method stub

    }
};