用户在点击手机的返回按钮时,默认是推出当前的activty,但是有时用户不小心按到返回,所以需要给用户一个提示,这就需要重写onkeydown事件,实现的效果如下:
标签: Android SDK
代码片段(2) [全屏查看所有代码]
1. [图片] 截图
2. [代码][Java]代码 跳至 [2] [全屏预览]
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@Override public void onCreate(Bundle savedInstanceState) {
super .onCreate(savedInstanceState);
setContentView(R.layout.main);
}
protected void dialog() {
AlertDialog.Builder builder = new Builder(HanderTestActivty. this );
builder.setMessage( "确定要退出吗?" );
builder.setTitle( "提示" );
builder.setPositiveButton( "确认" ,
new android.content.DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
HanderTestActivty. this .finish();
}
});
builder.setNegativeButton( "取消" ,
new android.content.DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
builder.create().show();
}
@Override
public boolean onKeyDown( int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0 ) {
dialog();
return false ;
}
return false ;
}
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MainActivity如下:
main.xml如下: