widget(3、Toast)

Toast是一个提示小组件，最长用方法如下：

Toast toast = new Toast(this);
toast = Toast.makeText(getApplicationContext(),
    "提示:输入参数错误", Toast.LENGTH_SHORT); //持续时长
 toast.setGravity(Gravity.CENTER, 0, 0);//设置位置
LinearLayout toastView = (LinearLayout) toast.getView();
ImageView image = new ImageView(getApplicationContext());
image.setImageResource(R.drawable.ic_launcher);
toastView.addView(image, 0); //增加图片
toast.show();

备注:这里要注意的是Toast也是一个viewgroup，因此可以定制复杂布局的toast，如下：

LayoutInflater inflater = getLayoutInflater();  
View layout = inflater.inflate(R.layout.toast, (ViewGroup)findViewById(R.id.toast)); //自定义一个toast命名的layout
EditText text1 = (EditText)layout.findViewById(R.id.editText1);//获取布局中的某一个view
text1.setText("hello text1");        
Toast toast = new Toast(getApplicationContext());  
toast.setDuration(Toast.LENGTH_LONG);  
toast.setView(layout);  
toast.show();