从文档中可以看到:

警告:从Android Build开始。VERSION_CODES#R，用于针对API级别构建的应用程序。如果VERSION_CODES#R或更高，则此方法(setGravity)在文本toast上调用时是一个无操作。

这意味着setGravity不能再在API 30+中使用，必须找到另一个来实现所需的行为。

改变土司颜色、位置和底色的方法是:

Toast toast=Toast.makeText(getApplicationContext(),"This is advanced toast",Toast.LENGTH_LONG);
toast.setGravity(Gravity.BOTTOM | Gravity.RIGHT,0,0);
View view=toast.getView();
TextView  view1=(TextView)view.findViewById(android.R.id.message);
view1.setTextColor(Color.YELLOW);
view.setBackgroundResource(R.color.colorPrimary);
toast.show();

逐行解释:https://www.youtube.com/watch?v=5bzhGd1HZOc

 Toast toast = Toast.makeText(test.this,"bbb", Toast.LENGTH_LONG);
 toast.setGravity(Gravity.CENTER, 0, 0);
 toast.show();

//一个自定义toast类，可以显示自定义或默认toast)

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

            /**
             * @param 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();
            }

        }

您可以使用以下命令自定义Toast的位置:

setGravity(int gravity, int xOffset, int yOffset)

docs

这让你可以非常明确你想要吐司的位置。

关于xOffset和yOffset参数最有用的事情之一是，你可以使用它们来相对于某个视图放置Toast。

例如，如果你想要创建一个显示在按钮顶部的自定义Toast，你可以创建一个这样的函数:

// v is the Button view that you want the Toast to appear above 
// and messageId is the id of your string resource for the message

private void displayToastAboveButton(View v, int messageId)
{
    int xOffset = 0;
    int yOffset = 0;
    Rect gvr = new Rect();

    View parent = (View) v.getParent(); 
    int parentHeight = parent.getHeight();

    if (v.getGlobalVisibleRect(gvr)) 
    {       
        View root = v.getRootView();

        int halfWidth = root.getRight() / 2;
        int halfHeight = root.getBottom() / 2;

        int parentCenterX = ((gvr.right - gvr.left) / 2) + gvr.left;

        int parentCenterY = ((gvr.bottom - gvr.top) / 2) + gvr.top;

        if (parentCenterY <= halfHeight) 
        {
            yOffset = -(halfHeight - parentCenterY) - parentHeight;
        }
        else 
        {
            yOffset = (parentCenterY - halfHeight) - parentHeight;
        }

        if (parentCenterX < halfWidth) 
        {         
            xOffset = -(halfWidth - parentCenterX);     
        }   

        if (parentCenterX >= halfWidth) 
        {
            xOffset = parentCenterX - halfWidth;
        }  
    }

    Toast toast = Toast.makeText(getActivity(), messageId, Toast.LENGTH_SHORT);
    toast.setGravity(Gravity.CENTER, xOffset, yOffset);
    toast.show();       
}

Toast mytoast= Toast.makeText(getApplicationContext(), "Toast Message", 1);  
mytoast.setGravity(Gravity.CENTER_HORIZONTAL, 0, 0);  // for center horizontal
//mytoast.setGravity(Gravity.CENTER_VERTICAL);       // for center vertical 
//mytoast.setGravity(Gravity.TOP);                       // for top
mytoast.show();

上面的代码将帮助你在屏幕中间显示吐司，或者根据你的选择，根据你的需要设置吐司的重力

注意:对于这个过程，你必须使用object of Toast