java ImageView 上的 Android Studio switch 语句
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Android Studio switch statement on ImageView
提问by Charas
I am trying to use a switch statement on ImageView and assign a String value, so that in my onClick function, I can do some function depending on which ImageView is clicked and use the String value depending on the ImageView clicked. Sorry for the bad explanation, below is the code sample.
我试图在 ImageView 上使用 switch 语句并分配一个字符串值，以便在我的 onClick 函数中，我可以根据单击的 ImageView 执行一些功能，并根据单击的 ImageView 使用字符串值。抱歉解释不好，下面是代码示例。
ChooseLevelActivity.java
选择LevelActivity.java
public class ChooseLevelActivity extends Activity implements View.OnClickListener {
ImageView level001, level002, level003, level004, level005;
String level_selected;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.choose_level);
level001 = (ImageView) findViewById(R.id.level001);
level002 = (ImageView) findViewById(R.id.level002);
level003 = (ImageView) findViewById(R.id.level003);
level004 = (ImageView) findViewById(R.id.level004);
level005 = (ImageView) findViewById(R.id.level005);
// Array of ImageView
final ImageView[] levelsArray = {level001, level002, level003, level004, level005};
for(int i = 0; i < 5; i++) {
levelsArray[i].setOnClickListener(this);
}
}
@Override
public void onClick(View v) {
/* Switch statement to change the value of String level_selected
* depending on which ImageView is clicked.
* but an error "Constant expression required" shows up
* What am I missing? How to use the switch on ImageView ?
*/
switch (v) {
case level001:
level_selected = "level001";
break;
case level002:
level_selected = "level002";
break;
}
// Some function that uses the String level_selected
}
}
采纳答案by Blackbelt
why don't use the idof the View, which is already constant, instead of comparing the v itself?
为什么不使用id已经是常量的 View 的，而不是比较 v 本身？
switch (v.getId()) {
case R.id.level001:
level_selected = "level001";
break;
case R.id.level002:
level_selected = "level002";
break;
}
