Question

我正在编写一个非常基本的Home Launcher，我在AppsGridActivity中创建了一个类AppsInfoModel，一个CustomAdapter和一个GridView。

这是我在Activity

中填充适配器的代码

function umbExtendImportController($scope, $routeParams, $http, navigationService) {

    $scope.runImport = function () {
        navigationService.hideNavigation();
    }

};

这是适配器

    appsGrid = (GridView) findViewById(R.id.appsGrid);
    appsInfo = new AppsInfoModel(this);
    appsGrid.setAdapter(new CustomAdapter(this,appsInfo));

}

和Model类

public class CustomAdapter extends BaseAdapter {

Context context;
AppsInfoModel appInfo;
CustomAdapter(Context context,AppsInfoModel appInfo) {
    this.context = context;
    this.appInfo = appInfo;
}

@Override
public int getCount() {
    return appInfo.getSize();
}

@Override
public Object getItem(int position) {
    return appInfo.getItem(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        convertView = inflater.inflate(R.layout.single_grid, parent, false);

        ImageView icon = (ImageView) convertView.findViewById(R.id.app_icon);
        icon.setImageDrawable(appInfo.getIcon(position));

        TextView label = (TextView) convertView.findViewById(R.id.app_label);
        label.setText(appInfo.getLabel(position));
        return convertView;
    }
    else
        return convertView;
}

这是Logcat错误

public class AppsInfoModel {
String label[];
String name[];
Drawable icon[];
PackageManager pm;
List<ResolveInfo> appsInfo;

AppsInfoModel(Context context){
    pm=context.getPackageManager();
    appsInfo = pm.queryIntentActivities(new Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_LAUNCHER), 0);
    for(int i=0;i<appsInfo.size();i++){
        label[i]= (appsInfo.get(i).loadLabel(pm)).toString();//***This is where problem lies according to LogCat***
        name[i]= (appsInfo.get(i)).activityInfo.packageName;
        icon[i]=(appsInfo.get(i)).activityInfo.loadIcon(pm);
    }
}

Drawable getIcon(int i){
    return icon[i];
}

String getLabel(int i){
    return label[i];
}

String getPackageName(int i){
    return name[i];
}
int getSize(){
    return appsInfo.size();
}

public ResolveInfo getItem(int i) {
    return appsInfo.get(i);
}
}

为什么会发生？逻辑或语法有什么问题。

Answer 1

根据您发布的代码，您没有初始化这些数组：

String label[];
String name[];
Drawable icon[];

你应该这样做：

AppsInfoModel(Context context){
    pm=context.getPackageManager();
    appsInfo = pm.queryIntentActivities(new Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_LAUNCHER), 0);

    label = new String[appsInfo.size()];
    name = new String[appsInfo.size()];
    icon = new Drawable[appsInfo.size()];
    for(int i=0;i<appsInfo.size();i++){
        label[i]= (appsInfo.get(i).loadLabel(pm)).toString();
        name[i]= (appsInfo.get(i)).activityInfo.packageName;
        icon[i]=(appsInfo.get(i)).activityInfo.loadIcon(pm);
    }
}

纠正logcat错误“尝试写入空数组”

1 个答案: