java android getResources（）。getIdentifier（）

Question

How do I get the int id value from R. for an id? When I use getIdentifier its just returns 0 .

 int i = getArguments().getInt(SELECTION_NUMBER);
 String drawerSelection = getResources().getStringArray(R.array.drawerSelection_array)[i];

int panelId = this.getResources().getIdentifier(drawerSelection.toLowerCase(),"id",getActivity().getPackageName());

Edit

Xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<ListView
    android:id="@+id/Bus_Schedules"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >
</ListView>

</LinearLayout>

log

06-10 21:24:30.372: I/System.out(3572): Selection = Bus_Schedules
06-10 21:24:30.372: I/System.out(3572): panelId = 0

R.java

    public static final class id {
    public static final int Bus_Schedules=0x7f090004;
    public static final int basemenu=0x7f090005;
    public static final int content_frame=0x7f090001;
    public static final int drawer_layout=0x7f090000;
    public static final int left_drawer=0x7f090002;

Answer 1

The problem appears to be that you are converting drawerSelection to lower case. As is clear in the R.java file, the case of the identifier is preserved. Try calling:

int panelId = this.getResources().getIdentifier(drawerSelection,"id",getActivity().getPackageName());

Answer 2

Just checked back in a project I'm writing right now:

int id = getResources().getIdentifier("resourcename", "drawable", getPackageName());

getResources returns int .

UPDATE: Check R.array.drawerSelection_array to include only ID's of existing elements.

Answer 3

Try this method.

public static int getResId(String fieldName, Context context, Class<?> c) {

    try {
        Field field= c.getDeclaredField(fieldName);
        return field.getInt(field);
    } catch (Exception e) {
        return 0;
    } 
}

Calling

 //edtUserName is my field id
 getResId("edtUserName", context, id.class);