Android - 如何使用setOnClickListener中另一个类的方法？

时间：2014-07-29 04:51:35

标签： android class button methods listener

我启动应用后，下面的代码崩溃了。我想用我的＆＃34; greenBackground＆＃34;和＆＃34; whiteBackground＆＃34; TestActivity的setOnClickListener方法中Methods.class的方法。有没有一种方法从Methods类调用方法？任何帮助表示赞赏。

TestActivity.class： 

package com.mfg.test;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;


public class TestActivity extends ActionBarActivity {

    Methods method = new Methods();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.program);

        Button greenButton = (Button) findViewById(R.id.GreenButton);
        Button whiteButton = (Button) findViewById(R.id.WhiteButton);

        greenButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                method.greenBackground(v);
            }
        });

        whiteButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                method.whiteBackground(v);
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.test, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

Methods.class： 

package com.mfg.test;

import android.graphics.Color;
import android.view.View;

public class Methods extends TestActivity {

    View rl = findViewById(R.id.rl);

    public void greenBackground(View rl)
    {
        rl.setBackgroundColor(Color.GREEN);
    }

    public void whiteBackground(View rl)
    {
        rl.setBackgroundColor(Color.WHITE);
    }
}

以下是日志文件： 

07-29 10:42:37.962: E/AndroidRuntime(2017): FATAL EXCEPTION: main
07-29 10:42:37.962: E/AndroidRuntime(2017): Process: com.mfg.test, PID: 2017
07-29 10:42:37.962: E/AndroidRuntime(2017): java.lang.StackOverflowError
07-29 10:42:37.962: E/AndroidRuntime(2017):     at java.lang.ref.FinalizerReference.<init>(FinalizerReference.java:42)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at java.lang.ref.FinalizerReference.add(FinalizerReference.java:54)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at android.os.StrictMode$InstanceTracker.<init>(StrictMode.java:2244)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at android.os.StrictMode.trackActivity(StrictMode.java:1946)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at android.app.Activity.<init>(Activity.java:761)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at android.support.v4.app.FragmentActivity.<init>(FragmentActivity.java:76)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at android.support.v7.app.ActionBarActivity.<init>(ActionBarActivity.java:55)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:11)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>(Methods.java:6)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.TestActivity.<init>(TestActivity.java:13)
07-29 10:42:37.962: E/AndroidRuntime(2017):     at com.mfg.test.Methods.<init>

似乎＆＃34;方法方法=新方法（）;＆＃34; TestActivity类中的行。我该如何解决这个问题？

2 个答案:

答案 0 :(得分：3)

在setContentView(R.layout.program);之后的onCreate方法中获取Id：

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.program);

    Button greenButton = (Button) findViewById(R.id.GreenButton);
    Button whiteButton = (Button) findViewById(R.id.WhiteButton);

    more code goes here..

请不要忘记在Android清单文件中提及您的方法活动：

赞<activity android:name=".Methods" />

答案 1 :(得分：0)

我不明白你想做什么，但这似乎是一个非常糟糕的结构。发生StackOverflowException是因为你的程序变得无限递归这两个类。你真的需要方法活动吗？

greenButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View greenButton) {
            greenButton.setBackgroundColor(Color.GREEN);
        }
    });

该侦听器中的View参数是greenButton本身，因此您可以使用它并设置背景颜色。

<强>解释

你不需要Activity，你可以像以下那样制作普通类：

public class Methods{

public void greenBackground(View rl) {
    rl.setBackgroundColor(Color.GREEN);
}

public void whiteBackground(View rl) {
    rl.setBackgroundColor(Color.WHITE);
}

}

在您的活动中创建一个实例，并在没有不必要的引用的情况下使用它。

相关问题
最新问题