Android應用開發之手勢識別

第一步：建立手勢庫

使用SDK自帶例子GestureBuilder建立手勢庫（位置：android-sdk-windows\samples\android-8\GestureBuilder）。使用GestureBuilder之前，你需要恢復其到開發環境，然後進行編繹並部署到手機上。此時，就可以使用GestureBuilder建立手勢庫，生成的手勢庫文件在SCDard上，默認文件名稱爲：gestures

 

第二步：在應用中加載手勢庫文件，然後開發手勢識別代碼。

把手勢庫文件gestures文件拷貝到項目的res/raw目錄下。然後在佈局文件中添加用於手勢繪製的View：

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

爲View添加手勢監聽事件：gestureOverlayView.addOnGesturePerformedListener();

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

加載手勢庫：mLibrary.load();

List<Prediction>predictions = mLibrary.recognize(gesture);//從手勢庫中查詢匹配的內容，匹配的結果可能包括多個相似的內容，匹配度高的結果放在最前面

大多數情況下，手勢都是通過一筆完成。然而有一些特別的需求就需要通過多個筆畫來實現，這時可以使用gestureStrokeType屬性進行設置：android:gestureStrokeType="multiple"

 

手勢識別代碼

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);
        //當用戶完成一次Gesture繪製後，系統將自動調用Listener對象的onGesturePerformed()方法
        gestureOverlayView.addOnGesturePerformedListener(new GestureListener());
        mLibrary = GestureLibraries.fromRawResource(this, R.raw.gestures);
        state = mLibrary.load();//加載手勢庫
    }
    
    private final class GestureListener implements GestureOverlayView.OnGesturePerformedListener{
		@Override
		public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
			if(state){
				List<Prediction> predictions = mLibrary.recognize(gesture);//從手勢庫中查詢匹配的內容，匹配的結果可能包括多個相似的結果，匹配度高的結果放在最前面
				if(!predictions.isEmpty()){
					Prediction prediction = predictions.get(0);
					//prediction的score屬性代表了與手勢的相似程度
					//prediction的name代表手勢對應的名稱
					if(prediction.score > 1){
						addressText.setText(prediction.name);
					}
				}
			}
		}
    }
}

實驗：

1、 將gesture文件放入工程res/raw/

2、 字符串資源

 <string name="norecohnize">不能識別該手勢</string>
    <string name="nopediction">手勢識別百分率太低,請重新輸入</string>

3、 佈局

<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());

		// 創建手勢庫對象
		libary = GestureLibraries.fromRawResource(this, R.raw.gestures);
		// 加載手勢資源
		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) { // 用戶輸入手勢與手勢庫中保存手勢相似度大於10%
					if ("close".equals(prediction.name)) {
						finish();
					} else if ("dialto".equals(prediction.name)) {
						Intent intent = new Intent(Intent.ACTION_CALL,
								Uri.parse("tel:[phone]"));
						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();
	}
}