kotlin使用bundle.getString尝试捕获块

我们有传递回某个活动的意图附加项

我们不理解为什么代码需要在try-catch块中

返回此活动的导航是通过各种意图完成的,这些意图并不总是放置捆绑包获得的所有值。

    val intent = Intent(this,MainActivity::class.java)
    intent.putExtra("FROM", "NEW")
    intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
    startActivity(intent)

而另一个按钮使用此代码

        holder.ivEdit.setOnClickListener {

        //val rowid = friendList.get(position).id
        val intent = Intent(context, MainActivity::class.java)
        intent.putExtra("FROM", "UPDATE")
        intent.putExtra("recordID", items.id)
        intent.putExtra("PERSON", items.person)
        intent.putExtra("PHONE", items.phone)
        intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
        context.startActivity(intent)
    }

代码在onCreate函数中

        try {
        val bundle: Bundle = intent.extras
        from = bundle.getString("FROM","")
        txtPerson = bundle.getString("PERSON","")
        txtPhone = bundle.getString("PHONE","")

        if(from == "UPDATE") {
            showMSG("To CANCEL use back button")
            id = bundle.getInt("recordID", 4)
            btnAdd.visibility = View.INVISIBLE
            btnEdit.visibility = View.VISIBLE
            btnViewList.visibility = View.INVISIBLE
            etPerson.setText(txtPerson)
            etPhone.setText(txtPhone)

        }else if (from == "DELETE"){

            showMSG("To CANCEL use back button")
            btnAdd.visibility = View.INVISIBLE
            btnViewList.visibility = View.INVISIBLE
            btnEdit.visibility = View.INVISIBLE
            btnDelete.visibility = View.VISIBLE
            etPerson.setText(txtPerson)
            etPhone.setText(txtPhone)
            etPerson.isEnabled = false
            etPhone.isEnabled = false

        }else{

            btnViewList.visibility = View.VISIBLE
            btnAdd.visibility = View.VISIBLE
            btnEdit.visibility = View.INVISIBLE
        }
        if (id != 0) {
            //etPerson.setText(txtPerson)
            //etPhone.setText(txtPhone)
        }
    } catch (ex: Exception) {
    }