如何在不点击的情况下更改ImageButton的背景？

Question

我有四个图像按钮，我想以编程方式更改其背景，而无需使用onClickListener。

public class playactivity extends Activity {

private ImageButton first;
private ImageButton second;
private ImageButton third;
private ImageButton fourth;
private int stage1;
private database db1;
static boolean sw=false;
static boolean sw1=false;
static boolean sw2=false;
static int c1,c2,c3,c4=0;
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.playactivity);
    first=(ImageButton)findViewById(R.id.firstbtn);
    second=(ImageButton)findViewById(R.id.secbtn);
    third=(ImageButton)findViewById(R.id.thirdbtn);
    fourth=(ImageButton)findViewById(R.id.fourthbtn);

     db1=new database(this);

      db1.useable();
      db1.open();
      stage1=db1.newstage(1);
      //stages of game

    if(stage1 == 1)
        second.setImageResource(R.drawable.unlock);
    else if(stage1 == 2)
    {
        second.setImageResource(R.drawable.unlock);
        third.setImageResource(R.drawable.unlock);
    }

    else if(stage1 == 3)
    {
        second.setImageResource(R.drawable.unlock);
        third.setImageResource(R.drawable.unlock);
         fourth.setImageResource(R.drawable.unlock);
    }
    first.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);
            c1++;

}
     });

    second.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {
            if(sw){

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);
            c2++;
        //  second.setImageResource(R.drawable.unlock); <--

            }
}
     });


    third.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {
            if(sw1){

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);  
            c3++;
       //third.setImageResource(R.drawable.unlock); <--
            }

}
     });
    fourth.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {
            if(sw2){

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);
            c4++;
         // fourth.setImageResource(R.drawable.unlock); <--
            }

}
     });

}}

这段代码不起作用，但奇怪的是，我可以使用像这样的onClickListener更改按钮的背景：

second.setOnClickListener(new OnClickListener() {

    public void onClick(View view) {
        if (sw) {
            Intent intent = new Intent(PlayActivity.this, Main.class);
            startActivity(intent);
            c2++;
            second.setImageResource(R.drawable.unlock);
        }
    }
});


third.setOnClickListener(new OnClickListener(){

    public void onClick(View view) {
        if (sw1) {
            Intent intent = new Intent(PlayActivity.this, Main.class);
            startActivity(intent);  
            c3++;
            third.setImageResource(R.drawable.unlock);
        }
    }
});

Answer 1

这是我的问题的答案:)

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.playactivity);
    first=(ImageButton)findViewById(R.id.firstbtn);
    second=(ImageButton)findViewById(R.id.secbtn);
    third=(ImageButton)findViewById(R.id.thirdbtn);
    fourth=(ImageButton)findViewById(R.id.fourthbtn);


    first.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);
            c1++;

}
     });

    second.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {
            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);
            c2++;
          }
     });


    third.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);  
            c3++;
   }
     });
    fourth.setOnClickListener(new OnClickListener(){
        public void onClick(View arg0) {

            Intent first1=new Intent(playactivity.this,Main.class);
            startActivity(first1);
            c4++;
            }
     });


   }
@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
     db1=new database(this);

      db1.useable();
      db1.open();
      stage1=db1.newstage(1);


    if(stage1 == 1)
    {
        //Resources resources = getResources(); 
    //  second.setImageDrawable(resources.getDrawable(R.drawable.unlock));

        second.setImageResource(R.drawable.unlock);
    }
        else if(stage1 == 2)
    {
        second.setImageResource(R.drawable.unlock);
        third.setImageResource(R.drawable.unlock);
    }

    else if(stage1 == 3)
    {
        second.setImageResource(R.drawable.unlock);
        third.setImageResource(R.drawable.unlock);
         fourth.setImageResource(R.drawable.unlock);
    }
}