可获取文本信息的Dialog

 final EditText et = new EditText(this);

 new AlertDialog.Builder(this).setTitle("搜索")
 .setIcon(android.R.drawable.ic_dialog_info)
 .setView(et)
 .setPositiveButton("确定", new OnClickListener() {
     public void onClick(DialogInterface dialog, int which) {
     String input = et.getText().toString();
     if (input.equals("")) {
         Toast.makeText(getApplicationContext(), "搜索内容不能为空！" + input, Toast.LENGTH_LONG).show();
     }
     else {
         Intent intent = new Intent();
         intent.putExtra("content", input);
         intent.setClass(MainActivity.this, SearchActivity.class);
         startActivity(intent);
         }
     }
     })
 .setNegativeButton("取消", null)
 .show();