Android应用开发之手势识别

第一步：建立手势库

使用SDK自带例子GestureBuilder建立手势库（位置：android-sdk-windows\samples\android-8\GestureBuilder）。使用GestureBuilder之前，你需要恢复其到开发环境，然后进行编绎并部署到手机上。此时，就可以使用GestureBuilder建立手势库，生成的手势库文件在SCDard上，默认文件名称为：gestures

 

第二步：在应用中加载手势库文件，然后开发手势识别代码。

把手势库文件gestures文件拷贝到项目的res/raw目录下。然后在布局文件中添加用于手势绘制的View：

 <android.gesture.GestureOverlayView
    android:id="@+id/gestures"
    android:layout_width="fill_parent“ android:layout_height="0dip"
    android:layout_weight="1.0" />

为View添加手势监听事件：gestureOverlayView.addOnGesturePerformedListener();

得到手势库：mLibrary =GestureLibraries.fromRawResource(this, R.raw.gestures);

加载手势库：mLibrary.load();

List<Prediction>predictions = mLibrary.recognize(gesture);//从手势库中查询匹配的内容，匹配的结果可能包括多个相似的内容，匹配度高的结果放在最前面

大多数情况下，手势都是通过一笔完成。然而有一些特别的需求就需要通过多个笔画来实现，这时可以使用gestureStrokeType属性进行设置：android:gestureStrokeType="multiple"

 

手势识别代码

public class MainActivity extends Activity {
    private GestureOverlayView gestureOverlayView;
    private GestureLibrary mLibrary;
    private boolean state;
    private EditText addressText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        addressText = (EditText)this.findViewById(R.id.address);
        gestureOverlayView = (GestureOverlayView)this.findViewById(R.id.gestures);
        //当用户完成一次Gesture绘制后，系统将自动调用Listener对象的onGesturePerformed()方法
        gestureOverlayView.addOnGesturePerformedListener(new GestureListener());
        mLibrary = GestureLibraries.fromRawResource(this, R.raw.gestures);
        state = mLibrary.load();//加载手势库
    }
    
    private final class GestureListener implements GestureOverlayView.OnGesturePerformedListener{
		@Override
		public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
			if(state){
				List<Prediction> predictions = mLibrary.recognize(gesture);//从手势库中查询匹配的内容，匹配的结果可能包括多个相似的结果，匹配度高的结果放在最前面
				if(!predictions.isEmpty()){
					Prediction prediction = predictions.get(0);
					//prediction的score属性代表了与手势的相似程度
					//prediction的name代表手势对应的名称
					if(prediction.score > 1){
						addressText.setText(prediction.name);
					}
				}
			}
		}
    }
}

实验：

1、 将gesture文件放入工程res/raw/

2、 字符串资源

 <string name="norecohnize">不能识别该手势</string>
    <string name="nopediction">手势识别百分率太低,请重新输入</string>

3、 布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <android.gesture.GestureOverlayView
        android:id="@+id/myGresture"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1.0" />

</LinearLayout>

4、 MyGestureTestActivity

package cn.class3g.gesture;
…
public class MyGestureTestActivity extends Activity {

	GestureOverlayView gestureView = null;
	GestureLibrary libary = null;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		init();
	}

	private void init() {
		gestureView = (GestureOverlayView) this.findViewById(R.id.myGresture);
		gestureView
				.addOnGesturePerformedListener(new MyOnGesturePerformedListener());

		// 创建手势库对象
		libary = GestureLibraries.fromRawResource(this, R.raw.gestures);
		// 加载手势资源
		libary.load();

	}

	private final class MyOnGesturePerformedListener implements
			OnGesturePerformedListener {

		public void onGesturePerformed(GestureOverlayView overlay,
				Gesture gesture) {

			ArrayList<Prediction> predictions = libary.recognize(gesture);
			if (!predictions.isEmpty()) {
				Prediction prediction = predictions.get(0);
				Log.i("TAG", String.valueOf(prediction.score));

				if (prediction.score > 5) { // 用户输入手势与手势库中保存手势相似度大于10%
					if ("close".equals(prediction.name)) {
						finish();
					} else if ("dialto".equals(prediction.name)) {
						Intent intent = new Intent(Intent.ACTION_CALL,
								Uri.parse("tel:133123145678"));
						startActivity(intent);
					}
				} else {
					showToast(R.string.norecohnize);
				}
			} else {
				showToast(R.string.nopediction);
			}

		}
	}

	private void showToast(int resId) {
		Toast.makeText(this, resId, Toast.LENGTH_LONG).show();
	}
}