public class MainActivity extends AppCompatActivity {
private final int item_4 = 4;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn = (Button) findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onPrepareOptionsMenu();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater mi = getMenuInflater();
mi.inflate(R.menu.menu_main, menu);
menu.add(Menu.NONE, item_4, Menu.NONE, "Show");
menu.add(Menu.NONE, item_4, Menu.NONE, "Hide");
menu.add("Reset");
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.item1:
Toast.makeText(this, "You Pressed Settings", Toast.LENGTH_SHORT).show();
return true;
case R.id.item2:
Toast.makeText(this, "You Pressed Create", Toast.LENGTH_SHORT).show();
return true;
case R.id.item3:
Toast.makeText(this, "You Pressed Delete", Toast.LENGTH_SHORT).show();
return true;
case item_4:
Toast.makeText(this, "You Pressed Hide", Toast.LENGTH_SHORT).show();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
MenuItem mii = menu.findItem(R.id.item2);
mii.setEnabled(false);
return super.onPrepareOptionsMenu(menu);
}
}
在上面的代碼中,我創建了應用程序欄的菜單項列表,並且在應用程序中創建了一個按鈕,並且我希望在按鈕單擊後禁用某些項目,但我無法做到這一點因爲我不gettig如何調用onPrepareOptionsMenu()上按鈕單擊?任何人都可以建議如何禁用按鈕單擊後的菜單項的解決方案?單擊按鈕後如何禁用菜單中的項目?