ToastUtil工具类

Android开发固然会用到Toast,如果每次都Toast.makeToast来显示Toast的话,一方面写法麻烦,第二是多次调用Toast会使Toast一直浮在界面最上层,影响交互,最好的方式是封装一个ToastUtil:

public class ToastUtil {

    private static volatile ToastUtil sToastUtil = null;

    private Toast mToast = null;

    /**
     * 获取实例
     *
     * @return
     */
    public static ToastUtil getInstance() {
        if (sToastUtil == null) {
            synchronized (ToastUtil.class) {
                if (sToastUtil == null) {
                    sToastUtil = new ToastUtil();
                }
            }
        }
        return sToastUtil;
    }

    protected Handler handler = new Handler(Looper.getMainLooper());

    /**
     * 显示Toast，多次调用此函数时，Toast显示的时间不会累计，并且显示内容为最后一次调用时传入的内容
     * 持续时间默认为short
     * @param tips 要显示的内容
     *            {@link Toast#LENGTH_LONG}
     */
    public void showToast(final String tips){
        showToast(tips, Toast.LENGTH_SHORT);
    }

    public void showToast(final int tips){
        showToast(tips, Toast.LENGTH_SHORT);
    }
    /**
     * 显示Toast，多次调用此函数时，Toast显示的时间不会累计，并且显示内容为最后一次调用时传入的内容
     *
     * @param tips 要显示的内容
     * @param duration 持续时间，参见{@link Toast#LENGTH_SHORT}和
     *            {@link Toast#LENGTH_LONG}
     */
    public void showToast(final String tips, final int duration) {
        if (android.text.TextUtils.isEmpty(tips)) {
            return;
        }
        handler.post(new Runnable() {
            @Override
            public void run() {
                if (mToast == null) {
                    mToast = Toast.makeText(MyApplication.getMyApplicationContext(), tips, duration);
                    mToast.show();
                } else {
                    //mToast.cancel();
                    //mToast.setView(mToast.getView());
                    mToast.setText(tips);
                    mToast.setDuration(duration);
                    mToast.show();
                }
            }
        });
    }

    public void showToast(final int tips, final int duration) {
        handler.post(new Runnable() {
            @Override
            public void run() {
                if (mToast == null) {
                    mToast = Toast.makeText(MyApplication.getMyApplicationContext(), tips, duration);
                    mToast.show();
                } else {
                    //mToast.cancel();
                    //mToast.setView(mToast.getView());
                    mToast.setText(tips);
                    mToast.setDuration(duration);
                    mToast.show();
                }
            }
        });
    }
}

其实Toast调用的Context为ApplicationContext,在Application中初始化即可.

public class MyApplication extends Application {

    private static Context myContext;

    @Override
    public void onCreate() {
        super.onCreate();
        myContext = this.getApplicationContext();
    }

    public static Context getMyApplicationContext(){
        return myContext;
    }
}