Question

所以基本上我有两个不同的CardView，一旦按下它们就想切换，因此我创建了ViewHolder作为这两个超类的持有者，即MaterialCardView。当我尝试验证收到的卡时，我在ViewHolder上使用instanceof。之后，我将CardView视为其原始类。但是，一旦这样做，就会出现Java错误“类型参数T具有不兼容的上限：视图和字符串”。

我尝试过使缓存和重构无效的解决方案，这是网站上的主要解决方案。不幸的是，这似乎是一个Java问题。

这是我的VH（到目前为止）：

public class ProjectItemHolder extends RecyclerView.ViewHolder {
    MaterialCardView projectItem;

    public ProjectItemHolder(MaterialCardView projectItem) {
        super(projectItem);
        if (projectItem instanceof unselectedCard) {
            ((unselectedCard) projectItem).imageUrl = itemView.findViewById(R.id.thumbnail);
            ((unselectedCard)projectItem).projectName = itemView.findViewById(R.id.projectName);
            ((unselectedCard)projectItem).projectDescription = itemView.findViewById(R.id.projectDescription);

我的unselectedCard类：

public class unselectedCard extends MaterialCardView {
    String projectName;
    String projectDescription;
    String imageUrl;

    public unselectedCard(Context context,String projectName, String projectDescription, String imageUrl) {
        super(context);
        this.projectName = projectName;
        this.projectDescription = projectDescription;
        this.imageUrl = imageUrl;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public String getProjectDescription() {
        return projectDescription;
    }

    public String getProjectName() {
        return projectName;
    }

    public void copyAnotherCard(unselectedCard card) {
        this.projectName = card.getProjectName();
        this.projectDescription = card.getProjectDescription();
        this.imageUrl = card.getImageUrl();
    }

和我要协调的其他Cardview：

public class selectedCard extends MaterialCardView {
    private String projectName,projectDescription,managerName;
    private String thumbnailUrl,imageUrl;

    public selectedCard(@NonNull Context context, String projectName, String projectDescription, String managerName, String thumbnailUrl, String imageUrl) {
        super(context);
        this.projectName = projectName;
        this.projectDescription = projectDescription;
        this.managerName = managerName;
        this.thumbnailUrl = thumbnailUrl;
        this.imageUrl = imageUrl;
    }

    public String getProjectName() {
        return projectName;
    }

    public String getProjectDescription() {
        return projectDescription;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public String getManagerName() {
        return managerName;
    }

    public String getThumbnailUrl() {
        return thumbnailUrl;
    }

    public void copyAnotherCard(selectedCard card) {
        this.projectName = card.getProjectName();
        this.projectDescription = card.getProjectDescription();
        this.managerName = card.getManagerName();
        this.thumbnailUrl = card.getThumbnailUrl();
        this.imageUrl = card.getImageUrl();
    }

我希望有人能告诉我如何解决此问题。

谢谢！

在ViewHolder上向下转换后如何上载视图？

0 个答案: