小编use*_*939的帖子

我已经看到了关于这个问题的其他几个问题,但似乎都没有解决我的问题.我有一个工作正常的自定义相机应用程序,除缩放按钮外的所有东西.这是使用SDK min 8 target 14的代码:

@Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width,
                int height) {
            if (isPreviewing){ 
                camera.stopPreview(); 
            }

            Camera.Parameters p = camera.getParameters();
            p.setPreviewSize(sizes.get(0).width, sizes.get(0).height);
            p.setColorEffect(effect); 

            zoomControls = (ZoomControls) findViewById(R.id.zoomControls);

            if (p.isZoomSupported()) {
                maxZoomLevel = p.getMaxZoom();
                Toast.makeText(PictureTaker.this, String.valueOf(maxZoomLevel),Toast.LENGTH_LONG).show();
                zoomControls.setIsZoomInEnabled(true);
                zoomControls.setIsZoomOutEnabled(true);

                zoomControls.setOnZoomInClickListener(new OnClickListener() {
                    public void onClick(View v) {
                        if (currentZoomLevel < maxZoomLevel) {
                            currentZoomLevel++;
                            camera.startSmoothZoom(currentZoomLevel);
                            //Toast.makeText(PictureTaker.this, String.valueOf(currentZoomLevel),Toast.LENGTH_LONG).show();
                        }
                    }
                });

                zoomControls.setOnZoomOutClickListener(new OnClickListener() {
                    public void onClick(View v) {
                        if (currentZoomLevel > 0) {
                            currentZoomLevel--;
                            camera.startSmoothZoom(currentZoomLevel);
                        }
                    }
                }); …

这是第一次发布海报,请原谅任何发布错误.也是Android的新手,我在试图找出共享偏好问题时遇到了问题.我声明我的常量如下

    private static SharedPreferences mSharedPreferences;
    static final String TWEET = null;

    static final String MEAL_ID = null;

和我的共同偏好如下

    mSharedPreferences = getApplicationContext().getSharedPreferences(
            "MyPref", 0);

我的简单测试代码如下:

    String msgTemp = "testing";
long iDTest = 234;
Editor e = mSharedPreferences.edit();
e.putLong(MEAL_ID, iDTest);
e.putString(TWEET, msgTemp);
e.commit();
String tempMsg = mSharedPreferences.getString(TWEET, "");
long tempId = mSharedPreferences.getLong(MEAL_ID, 0);
    Toast.makeText(getApplicationContext(),
    "Msg: " + tempMsg + " " + "ID: " + tempId, Toast.LENGTH_LONG).show();

返回以下错误:

    03-25 15:47:41.386: E/AndroidRuntime(28321): java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Long03-25 15:47:41.386: E/AndroidRuntime(28321):    at android.app.SharedPreferencesImpl.getLong(SharedPreferencesImpl.java:228) …