Android的发展：传递参数到onClickListener（） [英] Android Development: Passing a parameter into an onClickListener()

问题描述

基本上我创建中的一个按钮，用于循环，我需要每个按钮返回时pressed不同的值。

Basically I am creating buttons within a for loop, I need each button to return a different value when pressed.

我原以为创造我自己的onClickListener（）并传入需要的初始化时会工作参数的数据。它似乎有什么我想出了但没有语法错误，当按钮被点击运行时应用程序崩溃。

I had thought that creating my own onClickListener() and passing in the data needed as a parameter when it is initialized would work. It appears there are no syntax errors with what I came up with but when a button is clicked at run time the app crashes.

下面有什么，我已经得到了迄今为​​止的简化版本。

Heres a simplified version of what I've got thus far.

int counter = 1;
for( Program element :  someList)
    {
    //some other code for dynamically creating textviews to stick the buttons in

    //code which creates the buttons on the fly
    moreInfo = new Button(this);
    moreInfo.setText("More Info");  
    moreInfo.setOnClickListener(new DynamicOnClickListener(counter));
    counter++;

    }

自定义监听器类

import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Toast;

public class DynamicOnClickListener implements OnClickListener
{

    int counter;
    public DynamicOnClickListener(int acounter) {
         this.counter = acounter;
    }

    public void onClick(View v) {
        Log.v("DynamicOnClickListener","1");
        Toast.makeText(v.getContext(), counter, Toast.LENGTH_LONG).show();
    }

 }

所以理论上，如果这个工作的每个按钮将返回不同的号码，希望是有道理的。

So in theory if this worked each button would return a different number, hope that makes sense.

推荐答案

Toast.makeText 需要字符串资源ID作为第二个参数。您的计数器的值不是唯一的方式，您收到错误的有效资源ID。你需要传递一个字符串而不是 INT 的，它会正常工作。

Toast.makeText takes string resource id as a second argument. Your counter value is not a valid resource id that's way you are getting an error. You need to pass a String instead of int and it will work.

Toast.makeText(v.getContext(), String.valueOf(counter), Toast.LENGTH_LONG).show();

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