看起来我在这里做的一切都是正确的，但我肯定漏掉了什么。希望能解释一下为什么我在代码的第一行得到了那个错误，以及我应该如何解决这种问题？我是 Android 开发新手。
public class page2 extends AppCompatActivity implements OnClickListener {
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
ImageButton rock, scissors, paper;
Random randomNum = new Random();
int cpuMov;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activitypage2); //set what xml page style to display
rock = (ImageButton) findViewById(R.id.imageButtonRock);
scissors = (ImageButton) findViewById(R.id.imageButtonScissors);
paper = (ImageButton) findViewById(R.id.imageButtonPaper);
rock.setOnClickListener(new OnClickListener() { // calling onClick() method
@Override
//method for handling what happens when you click Rock buttonImage.
public void onClick(View v) {
// number between 1-3 inclusive (max-min+1)+1
cpuMov = randomNum.nextInt(3 - 1 + 1) + 1;
buildAlert(cpuMov, "imageButtonRock");
moveViewToScreenCenter(v);//float to center
}
});
scissors.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// number between 1-3 inclusive (max-min+1)+1
cpuMov = randomNum.nextInt(3 - 1 + 1) + 1;
buildAlert(cpuMov, "imageButtonScissors");
moveViewToScreenCenter(v);//float to center
}
});
paper.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// number between 1-3 inclusive (max-min+1)+1
cpuMov = randomNum.nextInt(3 - 1 + 1) + 1;
buildAlert(cpuMov, "imageButtonPaper");
moveViewToScreenCenter(v);//float to center
}
});
} //EoOnCreate
private void moveViewToScreenCenter( View view )
{
RelativeLayout root = (RelativeLayout) findViewById( R.id.rootLayout );
DisplayMetrics dm = new DisplayMetrics();
this.getWindowManager().getDefaultDisplay().getMetrics( dm );
int statusBarOffset = dm.heightPixels - root.getMeasuredHeight();
int originalPos[] = new int[2];
view.getLocationOnScreen( originalPos );
int xDest = dm.widthPixels/2;
xDest -= (view.getMeasuredWidth()/2);
int yDest = dm.heightPixels/2 - (view.getMeasuredHeight()/2) - statusBarOffset;
TranslateAnimation anim = new TranslateAnimation( 0, xDest - originalPos[0] , 0, yDest - originalPos[1] );
anim.setDuration(5000); // speed of the movement
anim.setFillAfter( true );
view.startAnimation(anim);
}
//builds the message that will be displayed
void appendMessage(AlertDialog.Builder myAlert, String cpuMove, String result) {
myAlert.setMessage("Computer selects " +cpuMove+ ", you " +result+ "!");
myAlert.show();
myAlert.setCancelable(true);
//how to give id to alertDialog to save in strings.xml
}
public void buildAlert(int move, String btnPressed) {
AlertDialog.Builder myAlert = new AlertDialog.Builder(this);
String cpuMove;
String result;
if (btnPressed.equals("imageButtonRock")) {
//Toast.makeText(this, "hooray "+move, Toast.LENGTH_SHORT).show();
if (move == 1) {
cpuMove = "Rock";
result = "tied";
//call appendMessage to append vars and display the message
appendMessage(myAlert, cpuMove, result);
}
if (move == 2) {
cpuMove = "Scissors";
result = "won";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
if (move == 3) {
cpuMove = "Paper";
result = "lost";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
} else if (btnPressed.equals("imageButtonScissors")) {
if (move == 1) {
cpuMove = "Rock";
result = "lost";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
if (move == 2) {
cpuMove = "Scissors";
result = "tied";
//call appendMessage to append vars and display the message
appendMessage(myAlert, cpuMove, result);
}
if (move == 3) {
cpuMove = "Paper";
result = "won";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
} else { //imageButton is Scissors
if (move == 1) {
cpuMove = "Rock";
result = "won";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
if (move == 2) {
cpuMove = "Scissors";
result = "lost";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
if (move == 3) {
cpuMove = "Paper";
result = "tied";
//call appendMessage to append vars and display the message
appendMessage(myAlert,cpuMove,result);
}
}
}
@Override
public void onStart() {
super.onStart();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client.connect();
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"page2 Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://rps.rsp/http/host/path")
);
AppIndex.AppIndexApi.start(client, viewAction);
}
@Override
public void onStop() {
super.onStop();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"page2 Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://rps.rsp/http/host/path")
);
AppIndex.AppIndexApi.end(client, viewAction);
client.disconnect();
}
}
我知道View.OnClickListener必须实现onClick()函数，那我没有做到吗？