Android onKeyDown() 在按下后退按钮时不执行
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/11822832/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Android onKeyDown() not execute on pressing back button
提问by Hardik Joshi
Hi after searching on google i come here to ask about help. I use following method to go back when user press back button of device.
嗨，在谷歌上搜索后，我来到这里寻求帮助。当用户按下设备的后退按钮时，我使用以下方法返回。
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
Log.i("===BACK BUTTON PRESSED===", "BACK BUTTON");
return true;
} else {
Log.i("===ELSE BACK BUTTON PRESSED===", "ELSE BACK BUTTON");
return super.onKeyDown(keyCode, event);
}
}
But logcat does not display any log message.
但 logcat 不显示任何日志消息。
W/KeyCharacterMap(517): No keyboard for id 0
W/KeyCharacterMap(517): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
Please help me to find this.
W/KeyCharacterMap(517): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
请帮我找到这个。
EDITED QUESTION :
编辑问题：
This is my entire class.
这是我的整个班级。
public class Dreams_Reminder_detail_screen extends Activity {
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
moveTaskToBack(true);
GroupDreams.group.back();
return true;
}
return super.onKeyDown(keyCode, event);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.dreams_reminder_details_screen);
}
}
}
回答by rajpara
You can override onBackPressed()function and implement your logic there.
您可以覆盖onBackPressed()函数并在那里实现您的逻辑。
Please refer this android blogpost "Back and other hard keys: three stories"for more understandings.
请参考这篇android博客文章“返回和其他硬键：三个故事”以获得更多理解。
You can overrided onKeyDown function in GroupDreams perhaps that will work
您可以在 GroupDreams 中覆盖 onKeyDown 函数，这可能会起作用
回答by Hardik Joshi
Try this link: Override back button to act like home button
试试这个链接：覆盖后退按钮像主页按钮一样
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
moveTaskToBack(true);
return true;
}
return super.onKeyDown(keyCode, event);
}
回答by HarrY
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
// do something on back.
return true;
}
return super.onKeyDown(keyCode, event);
}
//How to intercept the BACK key in an Activity is also one of the common questions we see //developers ask, so as of 2.0 we have a new little API to make this more simple and easier //to discover and get right:
@Override
public void onBackPressed() {
// do something on back.
return;
}
回答by Haresh Chaudhary
You can trace the Back Button Event this Way :-
您可以通过这种方式跟踪后退按钮事件：-
@Override
public void onBackPressed() {
super.onBackPressed();
//Do the Logics Here
}
回答by koti
Try with following code it will help you
尝试使用以下代码它会帮助你
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (event.getKeyCode() == KeyEvent.KEYCODE_BACK)
{
}
}
回答by Dhruvil Patel
you wrote super method in else{} that was wrong. Edit your code like this
您在 else{} 中编写了错误的超级方法。像这样编辑你的代码
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
Log.i("===BACK BUTTON PRESSED===", "BACK BUTTON");
return true;
} else {
Log.i("===ELSE BACK BUTTON PRESSED===", "ELSE BACK BUTTON");
}
return super.onKeyDown(keyCode, event);
}
