030、手写笔画的保存和读取（GestureOverlayView）

Android手机自SDK1.6开始支持内置Gesture Builder程序，提供了手写识别功能，让用户以类似涂鸦的方式绘制一个手写符号，使之对应一个字符串名称。

本例通过GestureOverlayView控件来接收用户的手写

1、手写笔画的生成保存：

效果图：

 

布局文件中GestureOverlayView：

    <android.gesture.GestureOverlayView
        android:id="@+id/gov"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/ll_bottom"
        android:layout_below="@id/ll_top"
        android:gestureStrokeType="multiple" >
    </android.gesture.GestureOverlayView>

默认是支持一笔，的添加android:gestureStrokeType="multiple"可以设置为支持多笔画

 

java代码：

    private EditText et;
    private GestureOverlayView gov;
    private Gesture gesture;
    private GestureLibrary gestureLibrary;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 判断是否有SD卡，无SD卡，则不运行该程序
        if (!Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
            Toast.makeText(this, "无SD卡，不能保存画好的图片", 0).show();
            finish();
        }
        findViews();
        setListeners();
    }
    private void findViews() {
        et = (EditText) findViewById(R.id.et);
        gov = (GestureOverlayView) findViewById(R.id.gov);
    }
    private void setListeners() {
        findViewById(R.id.bt_add).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                String name = et.getText().toString().trim();
                if (!TextUtils.isEmpty(name) && gesture != null) {
                    File file = new File(Environment
                            .getExternalStorageDirectory(), "gestures");
                    gestureLibrary = GestureLibraries.fromFile(file);
                    if (file.exists()) {
                        // 文件存在，应该先读取保存的gesture
                        if (gestureLibrary.load()) {
                            Set<String> gestureEntries = gestureLibrary
                                    .getGestureEntries();
                            if (gestureEntries.contains(name)) {
                                ArrayList<Gesture> gestures = gestureLibrary
                                        .getGestures(name);
                                for (Gesture ges : gestures) {
                                    gestureLibrary.removeGesture(name, ges);
                                }
                            }
                            gestureLibrary.addGesture(name, gesture);
                            saveToast(name);
                        } else {
                            Toast.makeText(MainActivity.this, "读取失败", 0).show();
                        }
                    } else {
                        // 文件不存在可以直接存入
                        gestureLibrary.addGesture(name, gesture);
                        saveToast(name);
                    }
                } else {
                    Toast.makeText(MainActivity.this, "文件名和图画都不能空哦", 0).show();
                }
            }
        });
        findViewById(R.id.bt_reset).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                et.setText("");
                gov.clear(true);
            }
        });
        
        findViewById(R.id.bt_show).setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, GestureListActivity.class);
                startActivity(intent);
            }
        });
        /**
         * 设置GestureOverlayView的OnGestureListener监听
         */
        gov.addOnGestureListener(new OnGestureListener() {
            @Override
            public void onGestureStarted(GestureOverlayView overlay,
                    MotionEvent event) {
                gesture = null;
            }
            @Override
            public void onGestureEnded(GestureOverlayView overlay,
                    MotionEvent event) {
                gesture = overlay.getGesture();
            }
            @Override
            public void onGestureCancelled(GestureOverlayView overlay,
                    MotionEvent event) {
            }
            @Override
            public void onGesture(GestureOverlayView overlay, MotionEvent event) {
            }
        });
    }
    
    private void saveToast(String name) {
        if (gestureLibrary.save()) {
            // 将设定画面数据清除
            et.setText("");
            gov.clear(true);
            Toast.makeText(MainActivity.this, name + "保存成功", 0)
                    .show();
        } else {
            Toast.makeText(MainActivity.this, name + "保存失败", 0)
                    .show();
        }
    }

 

2、获取已保存的笔画显示：

java代码如下：

    private void loadGestures() {
        titles.clear();
        images.clear();
        File file = new File(Environment.getExternalStorageDirectory(),
                "gestures");
        GestureLibrary gestureLibrary = GestureLibraries.fromFile(file);
        if (file.exists()) {
            // 文件存在时，先读取
            if (gestureLibrary.load()) {
                tv.setVisibility(View.GONE);
                // 读取gesture信息
                Object[] array = gestureLibrary.getGestureEntries().toArray();
                for (Object obj : array) {
                    ArrayList<Gesture> gestures = gestureLibrary
                            .getGestures(obj.toString());
                    for (Gesture ges : gestures) {
                        titles.add(obj.toString());
                        images.add(ges.toBitmap(80, 80, 5, Color.GREEN));
                    }
                }
            } else {
                // 读取失败
                tv.setVisibility(View.VISIBLE);
                tv.setText("读取失败");
            }
        } else {
            // 读取失败
            tv.setVisibility(View.VISIBLE);
            tv.setText("还没有保存过吧");
        }
    }