初学Android,从手势库识别手势(五十一)

接着上一篇，学习一下怎么识别手势，
首先还是要向AndroidManifest.xml添加SD卡的读写权限

<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical"
	android:layout_width="fill_parent"
	android:layout_height="fill_parent">
<!-- 使用手势编辑组件 -->	
<android.gesture.GestureOverlayView
	android:id="@+id/gesture"
	android:layout_width="fill_parent"
	android:layout_height="fill_parent"
	android:gestureStrokeType="multiple" />
</LinearLayout>

result.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical"
	android:layout_width="fill_parent"
	android:layout_height="fill_parent">
<ListView 
	android:id="@+id/show"
	android:layout_width="fill_parent"
	android:layout_height="fill_parent"
	/>	
</LinearLayout>

主界面代码

package WangLi.IO.RecogniseGesture;

import java.util.ArrayList;

import android.app.Activity;
import android.app.AlertDialog;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.Prediction;
import android.gesture.GestureOverlayView.OnGesturePerformedListener;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Toast;

public class RecogniseGesture extends Activity
{
	// 定义手势编辑组件
	GestureOverlayView gestureView;
	// 记录手机上已有的手势库
	GestureLibrary gestureLibrary;
	@Override
	public void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		// 读取上一个程序所创建的手势库
		gestureLibrary = GestureLibraries
			.fromFile("/sdcard/mygestures");
		if (gestureLibrary.load())
		{
			Toast.makeText(RecogniseGesture.this,"手势文件装载成功！" ,
				8000).show();
		}
		else
		{
			Toast.makeText(RecogniseGesture.this,"手势文件装载失败！" ,
				8000).show();
		}	
		// 获取手势编辑组件
		gestureView = (GestureOverlayView) findViewById(R.id.gesture);
		// 为手势编辑组件绑定事件监听器
		gestureView.addOnGesturePerformedListener(
			new OnGesturePerformedListener()
			{
				@Override
				public void onGesturePerformed(GestureOverlayView overlay,
					Gesture gesture)
				{
					// 识别用户刚刚所绘制的手势
					ArrayList<Prediction> predictions = gestureLibrary
						.recognize(gesture);
					ArrayList<String> result = new ArrayList<String>();
					//遍历所有找到的Prediction对象
					for (Prediction pred : predictions)
					{
						// 只有相似度大于2.0的手势才会被输出
						if (pred.score > 2.0)
						{
							result.add("与手势【" + pred.name + "】相似度为"
								+ pred.score);
						}
					}
					if (result.size() > 0)
					{
						ArrayAdapter adapter = new ArrayAdapter(
							RecogniseGesture.this,
							android.R.layout.simple_dropdown_item_1line, result
								.toArray());
						// 使用一个带List的对话框来显示所有匹配的手势
						new AlertDialog.Builder(RecogniseGesture.this)
							.setAdapter(adapter, null)
							.setPositiveButton("确定", null).show();
					}
					else
					{
						Toast.makeText(RecogniseGesture.this,"无法找到能匹配的手势！" ,
							8000).show();
					}
				}
			});
	}
}