Toast toast = new Toast(this); 
ImageView view = new ImageView(this); 
view.setImageResource(R.drawable.icon); 
toast.setView(view); 
toast.show();

//第二种图片加文字

Toast toast = Toast.makeText(this, "lalalal", Toast.LENGTH_LONG); 
View textView = toast.getView(); 
LinearLayout lay = new LinearLayout(this); 
lay.setOrientation(LinearLayout.HORIZONTAL); 
ImageView view = new ImageView(this); 
view.setImageResource(R.drawable.icon); 
lay.addView(view); 
lay.addView(textView); 
toast.setView(lay); 
toast.show();
//自定义位置
LayoutInflater inflater = getLayoutInflater();
   View layout = inflater.inflate(R.layout.custom,
     (ViewGroup) findViewById(R.id.llToast));
   ImageView image = (ImageView) layout
     .findViewById(R.id.tvImageToast);
   image.setImageResource(R.drawable.icon);
   TextView title = (TextView) layout.findViewById(R.id.tvTitleToast);
   title.setText("Attention");
   TextView text = (TextView) layout.findViewById(R.id.tvTextToast);
   text.setText("自定义Toast");
   toast = new Toast(getApplicationContext());
   toast.setGravity(Gravity.RIGHT | Gravity.TOP, 12, 40);
   toast.setDuration(Toast.LENGTH_LONG);
   toast.setView(layout);
   toast.show();

xcode4.2中为propery重写setter和getter方法会出现警告：

writable atomic property 'someProperty' cannot pair a synthesized setter/getter with a user defined setter/getter

解决方法之一：在声明propery(nonatomic, ...)中，加入nonatomic

NSFileManager *fileManager = [NSFileManager defaultManager];    
BOOL result = [fileManager fileExistsAtPath:@"/private/var/lib/apt/"];