Android程序真退出与假退出后台运行详解

public void onBackPressed() {
AlertDialog.Builder builder = new Builder(LawdaquanActivity.this);
builder.setIcon(R.drawable.imagebutton5);
builder.setTitle("提示");
builder.setMessage("你真的要退出法律信息软件吗？");
builder.setPositiveButton("是",
new android.content.DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent i = new Intent(Intent.ACTION_MAIN);

i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

i.addCategory(Intent.CATEGORY_HOME);

startActivity(i);

}
});
builder.setNegativeButton("否",
new android.content.DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
builder.create().show();
}

public void exitProgrames{

Intent startMain = new Intent(Intent.ACTION_MAIN);

startMain.addCategory(Intent.CATEGORY_HOME);

startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

startActivity(startMain);

android.os.Process.killProcess(android.os.Process.myPid());

public boolean onKeyDown(int keyCode, KeyEvent event) {

if (keyCode == KeyEvent.KEYCODE_BACK) {
new AlertDialog.Builder(this)
.setIcon(R.drawable.title)
.setTitle("退出软件")
.setMessage("是否退出法律文书软件")
.setPositiveButton("否",
new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog,
int which) {
// TODO Auto-generated method stub

}
}).setNegativeButton("退出", new OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
finish();
}
}).create().show();
}

else {
return super.onKeyDown(keyCode, event);

}

// TODO Auto-generated method stub
return super.onKeyDown(keyCode, event);
}

Intent i = new Intent(Intent.ACTION_MAIN);

i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

i.addCategory(Intent.CATEGORY_HOME);

startActivity(i);
finish();