所有屏幕中的自定义Toast消息？

Question

我开发了一个有15个屏幕的应用程序.现在我想在所有这15个屏幕中显示自定义Toast消息.为此,我夸大了一个布局.但它只在一个屏幕上工作.所以,我写了一个方法来Toast在所有屏幕上显示自定义.每当我想显示toast消息时,我就会调用该方法.但我得到了java.lang.NullPointerException.怎么解决这个？以下是我的代码,

public static void showToastMessage(String message){

               LayoutInflater inflater = ((Activity) context).getLayoutInflater();

                View layout = inflater.inflate(R.layout.custom_toast,
                  (ViewGroup) ((Activity) context).findViewById(R.id.customToast));
            // set a message
                TextView text = (TextView) layout.findViewById(R.id.text);
                text.setText(message);

                // Toast...
                Toast toast = new Toast(context);
                toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
                toast.setDuration(Toast.LENGTH_LONG);
                toast.setView(layout);
                toast.show();
           }

记录是

java.lang.NullPointerException

    at com.guayama.utilities.CommonMethods.showToastMessage(CommonMethods.java:474)

    at android.view.View.performClick(View.java:3511)

    at android.view.View$PerformClick.run(View.java:14105)

    at android.os.Handler.handleCallback(Handler.java:605)

    at android.os.Handler.dispatchMessage(Handler.java:92)

    at android.os.Looper.loop(Looper.java:137)

    at android.app.ActivityThread.main(ActivityThread.java:4424)

    at java.lang.reflect.Method.invokeNative(Native Method)

Answer 1

改变你的方法

从

showToastMessage(String message)

至

showToastMessage(Context context,String message);

这对我来说似乎是背景问题

你的功能会是这样的

public static void showToastMessage(Context context,String message){

               LayoutInflater inflater = context.getLayoutInflater();

                View layout = inflater.inflate(R.layout.custom_toast,
                  (ViewGroup) ((Activity) context).findViewById(R.id.customToast));
            // set a message
                TextView text = (TextView) layout.findViewById(R.id.text);
                text.setText(message);

                // Toast...
                Toast toast = new Toast(context);
                toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
                toast.setDuration(Toast.LENGTH_LONG);
                toast.setView(layout);
                toast.show();
           }

Answer 2

Toast 的自定义类实现，可用于任何项目。

public class ToastMessage {
        private Context context;
        private static ToastMessage instance;

    /**
     * @para
   m context
     */
    private ToastMessage(Context context) {
        this.context = context;
    }

    /**
     * @param context
     * @return
     */
    public synchronized static ToastMessage getInstance(Context context) {
        if (instance == null) {
            instance = new ToastMessage(context);
        }
        return instance;
    }

    /**
     * @param message
     */
    public void showLongMessage(String message) {
        Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
    }

    /**
     * @param message
     */
    public void showSmallMessage(String message) {
        Toast.makeText(context, message, Toast.LENGTH_LONG).show();
    }

    /**
     * The Toast displayed via this method will display it for short period of time
     *
     * @param message
     */
    public void showLongCustomToast(String message) {

        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        View layout = inflater.inflate(R.layout.layout_custom_toast, (ViewGroup) ((Activity) context).findViewById(R.id.ll_toast));
        TextView msgTv = (TextView) layout.findViewById(R.id.tv_msg);
        msgTv.setText(message);
        Toast toast = new Toast(context);
        toast.setGravity(Gravity.FILL_HORIZONTAL | Gravity.BOTTOM, 0, 0);
        toast.setDuration(Toast.LENGTH_LONG);
        toast.setView(layout);
        toast.show();

    }

    /**
     * The toast displayed by this class will display it for long period of time
     *
     * @param message
     */
    public void showSmallCustomToast(String message) {

        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        View layout = inflater.inflate(R.layout.layout_custom_toast, (ViewGroup) ((Activity) context).findViewById(R.id.ll_toast));
        TextView msgTv = (TextView) layout.findViewById(R.id.tv_msg);
        msgTv.setText(message);
        Toast toast = new Toast(context);
        toast.setGravity(Gravity.FILL_HORIZONTAL | Gravity.BOTTOM, 0, 0);
        toast.setDuration(Toast.LENGTH_SHORT);
        toast.setView(layout);
        toast.show();
    }

}