Question

我是编程新手，我试图使用相机拍摄的图像填充RecyclerView。每当我拍摄新照片时，我都希望被添加到RecyclerView并更新RecyclerView。

RecyclerView适用于TextViews（例如），但它不会显示Imageview。我认为当我尝试获取捕获的图像的URI时会出现问题。

我还没有为这个主题找到太多解决方案，所以我要问你们。

这是模型类。

#include <windows.h>
#include <commctrl.h>
#include <richedit.h>
#include <string>

#pragma comment(lib, "comctl32.lib")
#pragma comment(linker,"\"/manifestdependency:type='win32' \
    name='Microsoft.Windows.Common-Controls' version='6.0.0.0' \
    processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")

LRESULT CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK RichEditProc(HWND, UINT, WPARAM, LPARAM);

WNDPROC richEditOrigProc;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    LoadLibrary(TEXT("msftedit.dll"));

    WNDCLASSEX mainwcex;
    mainwcex.cbSize = sizeof(WNDCLASSEX);
    mainwcex.style = CS_HREDRAW | CS_VREDRAW;
    mainwcex.lpfnWndProc = WindowProc;
    mainwcex.cbClsExtra = 0;
    mainwcex.cbWndExtra = 0;
    mainwcex.hInstance = hInstance;
    mainwcex.hIcon = NULL;
    mainwcex.hCursor = (HICON)LoadCursor(NULL, IDC_ARROW);
    mainwcex.hbrBackground = GetSysColorBrush(COLOR_MENU);
    mainwcex.lpszMenuName = NULL;
    mainwcex.lpszClassName = "mainwindow";
    mainwcex.hIconSm = NULL;

    RegisterClassEx(&mainwcex);

    HWND mainWindow = CreateWindowEx(
        NULL,
        "mainwindow",
        NULL,
        WS_OVERLAPPEDWINDOW,
        100,
        100,
        600,
        400,
        NULL,
        NULL,
        hInstance,
        NULL);

    HWND richEditControl = CreateWindowEx(
        NULL,
        "RICHEDIT50W",
        "Rich Edit",
        WS_CHILD | WS_VISIBLE | WS_BORDER | WS_TABSTOP,
        50,
        50,
        100,
        25,
        mainWindow,
        NULL,
        hInstance,
        NULL);

    richEditOrigProc = (WNDPROC) SetWindowLongPtr(richEditControl, GWLP_WNDPROC, (LONG_PTR) RichEditProc);

    // Changes the width of rich edit control from 100 px to 400 px.
    SetWindowPos(richEditControl, NULL, 0, 0, 400, 25,
        SWP_NOMOVE | SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_NOACTIVATE);

    ShowWindow(mainWindow, nCmdShow);

    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0)) {
        if (!IsDialogMessage(mainWindow, &msg)) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    return static_cast<int>(msg.wParam);
}

LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg) {
        case WM_DESTROY:
        {
            PostQuitMessage(0);
            return 0;
        }
    }
    return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

LRESULT CALLBACK RichEditProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg) {
        case WM_NCCALCSIZE:
        {
            if (wParam) {
                NCCALCSIZE_PARAMS* ncParams = reinterpret_cast<NCCALCSIZE_PARAMS*>(lParam);
                ncParams->rgrc[0].left += 50;
                ncParams->rgrc[0].top += 3;
                ncParams->rgrc[0].right -= 50;
                ncParams->rgrc[0].bottom -= 3;
                return WVR_HREDRAW;
            }
            return 0;
        }
    }
    return CallWindowProc(richEditOrigProc, hWnd, uMsg, wParam, lParam);
}

这是适配器。

public class Attachment {
private Uri image;
private String text;

public Attachment(Uri image, String text) {
    this.image = image;
    this.text = text;
}

public Uri getImage() {
    return image;
}

public String getText(){
    return text;
}

我在这里传递了意图。

public class ListViewAdapter extends RecyclerView.Adapter<ListViewAdapter.ViewHolder> {

private Context context;
private List<Attachment> lista;
private LayoutInflater layoutInflater;


public ListViewAdapter(List<Attachment> lista, Context context) {
    this.lista = lista;
    this.context = context;
    layoutInflater=LayoutInflater.from(context);
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view=layoutInflater.inflate(R.layout.listview_layout, parent, false);
    ViewHolder viewHolder=new ViewHolder(view);

    return viewHolder;
}

@Override
public void onBindViewHolder(ListViewAdapter.ViewHolder holder, int position) {
    holder.imageView.setImageURI(lista.get(position).getImage());
    holder.textView.setText(lista.get(position).getText());
}

@Override
public int getItemCount() {
    return lista.size();
}

public static class ViewHolder extends RecyclerView.ViewHolder{

    public ImageView imageView;
    public TextView textView;

    public ViewHolder(View itemView) {
        super(itemView);

        imageView=itemView.findViewById(R.id.listviewAttachmentImageView);
        textView=itemView.findViewById(R.id.textView);
    }
}

public void update(List<Attachment> newList) {
    lista.clear();
    lista.addAll(newList);
    notifyDataSetChanged(); }

这里我初始化RecyclerView。

buttonAddAttachment.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            if (intent.resolveActivity(getPackageManager())!=null){
                startActivityForResult(intent,CAM_REQUEST);
            }
        }
    });

这是onActivityResult方法（单击相机按钮的结果）。

    list=new ArrayList<>();

    recyclerView=(RecyclerView)findViewById(R.id.recyclerview);
    recyclerView.setHasFixedSize(true);

    adapter=new ListViewAdapter(list, this);
    recyclerView.setAdapter(adapter);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    adapter.update(list);

Answer 1

在“附件”模型中，将图像更改为类型Uri

public class Attachment { 
    private Uri image; 
    public Attachment(Uri image) { this.image = image; } 
    public Uri getImage() { return image; }

在if语句之后的onActivityResult中执行

Uri uri = intent.getData();
Attachment att = new Attachment (uri);
List<Attachment> list = new ArrayList<>();
list.add(att);
.... = New ListViewAdapter(list, context);

protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
if (requestCode == CAM_REQUEST && resultCode == RESULT_OK) { 
    Uri uri = data.getData();
    Attachment att = new Attachment (uri);
    List<Attachment> list = new ArrayList<>();
    list.add(att);

    adapter=new ListViewAdapter(list,this);
    recyclerView.setAdapter(adapter);

}}

不要设置imageView。

在你的适配器类onBind

中

holder.imageView.setImageUri(lista.get(position).getImage());

Answer 2

添加recyclerview.setAdapter（适配器）;到你的onActivityResult

从相机拍摄的图像中获取URI

2 个答案: