沒有收益就吃麵包

找到Build.gradle(Project:xxxx)  xxxx<-專案名稱

private Handler worker;
worker= new Handler() {
    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case 1:
              
              break;
        }
    }};

private  ProgressDialog progressDialog ;//宣告

new Load().execute();//呼叫

class Load extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        progressDialog = ProgressDialog.show(bulletin_board_show.this, "載入中", "請稍後", true);

    }


    /**
     * getting All products from url
     * */
    protected String doInBackground(String... args) {


      

        progressDialog.dismiss();//關閉


        return null;

    }



}

Intent i=new Intent();

如果是.

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {

       //放返回後做的事

        return true;
    }
    return super.onKeyDown(keyCode, event);
}

xxxx.setOnClickListener(new Button.OnClickListener(){

    @Override

    public void onClick(View v) {

        // TODO Auto-generated method stub


    }

});

xxx是只 哪個button

比如你剛剛有拉一張圖片到drawable裡面