AlertDialog

//在setPositiveButton和setNegativeButton根据自己的逻辑处理，大概代码如下
if(validate){//验证通过自动消失
    setDialogDismissable(dialog, true);
}else{//验证没通过，不能消失
    setDialogDismissable(dialog, false)
}

void setDialogDismissable(DialogInterface dialog, booleandismissable){
        try{
            Field field = dialog.getClass().getSuperclass().getDeclaredField("mShowing");
            field.setAccessible(true); 
            field.set(dialog, dismissable);
        } catch(Exception e) {
            e.printStackTrace();
        } 
    }

final EditText textEdit = new EditText(this);

//Builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
//TODO:builder.setTitle("");

//Dialog
AlertDialog dialog =builder.create();
dialog.setOnShowListener(newOnShowListener() {

    @Override
    public voidonShow(DialogInterface dialog) {
        InputMethodManager imm =(InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.showSoftInput(textEdit, InputMethodManager.SHOW_IMPLICIT);
    }
});

dialog.show();