Binding Drag Events
The ArkUI framework provides a set of drag event APIs to help you implement drag-and-drop functionality.These events include NODE_ON_PRE_DRAG, NODE_ON_DRAG_START, NODE_ON_DROP, NODE_ON_DRAG_ENTER, NODE_ON_DRAG_MOVE, NODE_ON_DRAG_LEAVE, and NODE_ON_DRAG_END. These events are triggered at different stages of the drag operation, allowing you to perform specific actions and manage the drag interaction as needed.
Basic Drag Implementation
In ArkUI, you can implement the drag-and-drop functionality using C and C++ by calling C APIs. The following provides step-by-step instructions using the Image component as an example, along with key points to keep in mind during development.
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Set a component draggable.
Initialize nodeAPI using the OH_ArkUI_GetModuleInterface API. Node operations, such as creating a node, must be performed through nodeAPI.
ArkUI_NativeNodeAPI_1 *nativeNodeAPI = nullptr; OH_ArkUI_GetModuleInterface(ARKUI_NATIVE_NODE, ArkUI_NativeNodeAPI_1, nativeNodeAPI); nodeAPI = nativeNodeAPI;Create an Image node, use OH_ArkUI_SetNodeDraggable to set the node to be draggable, and set other related attributes.
dragImage2 = nodeAPI->createNode(ARKUI_NODE_IMAGE); SetId(dragImage2, "dragImage"); SetCommonAttribute(dragImage2, 140.0f, 140.0f, 0xFFFFFFFF, 5.0f); // Replace src/main/resources/base/media/seagull.png with the image resource file you use. SetImageSrc(dragImage2, "/resources/base/media/seagull.png"); OH_ArkUI_SetNodeDraggable(dragImage2, true); nodeAPI->registerNodeEvent(dragImage2, NODE_ON_DRAG_START, 1, nullptr);#define DEFAULT_WIDTH 200.0 // Set the node brightness. void SetWidth(ArkUI_NodeHandle &node, float width = DEFAULT_WIDTH) { if (!nodeAPI) { return; } ArkUI_NumberValue widthValue[] = {width}; ArkUI_AttributeItem widthItem = {widthValue, 1}; nodeAPI->setAttribute(node, NODE_WIDTH, &widthItem); } #define DEFAULT_HEIGHT 200.0 // Set the node height. void SetHeight(ArkUI_NodeHandle &node, float height = DEFAULT_HEIGHT) { if (!nodeAPI) { return; } ArkUI_NumberValue heightValue[] = {height}; ArkUI_AttributeItem heightItem = {heightValue, 1}; nodeAPI->setAttribute(node, NODE_HEIGHT, &heightItem); } #define DEFAULT_BG_COLOR 0xFFFFFFFF // Set the background color of the node. void SetBackgroundColor(ArkUI_NodeHandle &node, uint32_t color = DEFAULT_BG_COLOR) { if (!nodeAPI) { return; } ArkUI_NumberValue colorValue[] = {{.u32 = color}}; ArkUI_AttributeItem colorItem = {colorValue, 1}; nodeAPI->setAttribute(node, NODE_BACKGROUND_COLOR, &colorItem); } #define DEFAULT_MARGIN 5.0 // Set the margin of the node. void SetMargin(ArkUI_NodeHandle &node, float margin = DEFAULT_MARGIN) { if (!nodeAPI) { return; } ArkUI_NumberValue marginValue[] = {margin}; ArkUI_AttributeItem marginItem = {marginValue, 1}; nodeAPI->setAttribute(node, NODE_MARGIN, &marginItem); } // Set tags for a Button node. void SetButtonLabel(ArkUI_NodeHandle &node, const char *label) { if (!nodeAPI) { return; } ArkUI_AttributeItem NODE_Button_SRC_Item = {.string = label}; nodeAPI->setAttribute(node, NODE_BUTTON_LABEL, &NODE_Button_SRC_Item); } // Set the node identifier. void SetId(ArkUI_NodeHandle &node, const char *id) { if (!nodeAPI) { return; } ArkUI_AttributeItem idItem = {.string = id}; nodeAPI->setAttribute(node, NODE_ID, &idItem); } #define DEFAULT_BORDER_WIDTH 0.0 // Set the border width for the node. void SetBorderWidth(ArkUI_NodeHandle &node, float width = DEFAULT_BORDER_WIDTH) { if (!nodeAPI) { return; } ArkUI_NumberValue borderWidthValue[] = {width}; ArkUI_AttributeItem borderWidthItem = {borderWidthValue, 1}; nodeAPI->setAttribute(node, NODE_BORDER_WIDTH, &borderWidthItem); } #define DEFAULT_BORDER_COLOR 0xFF000000 // Set the border color of the node. void SetBorderColor(ArkUI_NodeHandle &node, uint32_t color = DEFAULT_BORDER_COLOR) { if (!nodeAPI) { return; } ArkUI_NumberValue borderColorValue[] = {{.u32 = color}}; ArkUI_AttributeItem borderColorItem = {borderColorValue, 1}; nodeAPI->setAttribute(node, NODE_BORDER_COLOR, &borderColorItem); } // Set common node attributes, such as the width, height, background color, margin, and border style. void SetCommonAttribute(ArkUI_NodeHandle &node, float width = DEFAULT_WIDTH, float height = DEFAULT_HEIGHT, unsigned int color = DEFAULT_BG_COLOR, float margin = DEFAULT_MARGIN) { SetWidth(node, width); SetHeight(node, height); SetBackgroundColor(node, color); SetMargin(node, margin); SetBorderWidth(node, DEFAULT_BORDER_WIDTH); SetBorderColor(node); }void SetImageSrc(ArkUI_NodeHandle &node, const char *src) { if (!nodeAPI) { return; } ArkUI_AttributeItem imageSrcItem = {.string = src}; nodeAPI->setAttribute(node, NODE_IMAGE_SRC, &imageSrcItem); } -
Customize the drag preview and background image.
Create a PixelMap object and set its width, height, and other properties. Set ArkUI_DragPreviewOption for the Image node to customize the rounded corners and badges of the drag preview.
// Create a PixelMap object. uint8_t data[960000]; size_t dataSize = 960000; for (int i = 0; i < dataSize; i++) { data[i] = i + 1; } // Create a parameter structure instance and set parameters. OH_Pixelmap_InitializationOptions *createOpts; OH_PixelmapInitializationOptions_Create(&createOpts); OH_PixelmapInitializationOptions_SetWidth(createOpts, 200U); OH_PixelmapInitializationOptions_SetHeight(createOpts, 200U); OH_PixelmapInitializationOptions_SetPixelFormat(createOpts, PIXEL_FORMAT_BGRA_8888); OH_PixelmapInitializationOptions_SetAlphaType(createOpts, PIXELMAP_ALPHA_TYPE_UNKNOWN); // Define the custom drag preview. OH_PixelmapNative *pixelmap = nullptr; OH_PixelmapNative_CreatePixelmap(data, dataSize, createOpts, &pixelmap); OH_PixelmapNative_Opacity(pixelmap, 0.1f); OH_ArkUI_SetNodeDragPreview(node, pixelmap); // Set the drag preview configuration options. auto *previewOptionsText = OH_ArkUI_CreateDragPreviewOption(); OH_ArkUI_DragPreviewOption_SetScaleMode(previewOptionsText, ARKUI_DRAG_PREVIEW_SCALE_DISABLED); OH_ArkUI_DragPreviewOption_SetNumberBadgeEnabled(previewOptionsText, true); OH_ArkUI_DragPreviewOption_SetBadgeNumber(previewOptionsText, 10U); OH_ArkUI_DragPreviewOption_SetDefaultShadowEnabled(previewOptionsText, true); OH_ArkUI_DragPreviewOption_SetDefaultRadiusEnabled(previewOptionsText, true); int returnValue = OH_ArkUI_DragPreviewOption_SetDefaultAnimationBeforeLiftingEnabled(previewOptionsText, true); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "Manager", "dragTest DragPreviewOption_SetDefaultAnimationBeforeLiftingEnabled returnValue = %{public}d", returnValue); OH_ArkUI_SetNodeDragPreviewOption(node, previewOptionsText); -
Set related events.
Use a unified callback to handle events. Distinguish between different events using eventType.
nodeAPI->addNodeEventReceiver(dragNode, [](ArkUI_NodeEvent *event) { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "RegisterNodeEventFirstReceiver called"); auto eventType = OH_ArkUI_NodeEvent_GetEventType(event); auto preDragStatus = OH_ArkUI_NodeEvent_GetPreDragStatus(event); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "eventType = %{public}d, preDragStatus = %{public}d", eventType, preDragStatus); auto *dragEvent = OH_ArkUI_NodeEvent_GetDragEvent(event); switch (eventType) { case NODE_ON_PRE_DRAG: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_PRE_DRAG Event Receive"); break; case NODE_ON_CLICK: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_CLICK Event Receive"); break; case NODE_ON_DROP: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DROP Event Receive"); break; case NODE_ON_DRAG_ENTER: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DRAG_ENTER Event Receive"); break; case NODE_ON_DRAG_MOVE: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DRAG_MOVE Event Receive"); break; case NODE_ON_DRAG_LEAVE: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DRAG_LEAVE Event Receive"); break; case NODE_ON_DRAG_START: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DRAG_START Event Receive"); // ... break; } case NODE_ON_DRAG_END: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DRAG_END Event Receive"); // ... break; } default: OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "UNKNOWN Event Receive"); break; } }); -
Handle the NODE_ON_DRAG_START event.
In the NODE_ON_DRAG_START event, perform operations required to initiate the drag operation, typically involving data processing. For example, create an OH_UdmfRecord, add the data imageValue required for dragging an image to OH_UdmfRecord as the OH_UdsFileUri type, then set OH_UdmfRecord into OH_UdmfData, and finally set OH_UdmfData into DragEvent.
void SetImageData(ArkUI_DragEvent* dragEvent) { int returnValue; OH_UdmfRecord *record = OH_UdmfRecord_Create(); OH_UdsFileUri *imageValue = OH_UdsFileUri_Create(); // Replace src/main/resources/base/media/seagull.png with the image resource file you use. returnValue = OH_UdsFileUri_SetFileUri(imageValue, "/resources/base/media/seagull.png"); returnValue = OH_UdmfRecord_AddFileUri(record, imageValue); OH_UdmfData *data = OH_UdmfData_Create(); returnValue = OH_UdmfData_AddRecord(data, record); returnValue = OH_ArkUI_DragEvent_SetData(dragEvent, data); } // ... case NODE_ON_DRAG_START: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DRAG_START EventReceiver"); SetImageData(dragEvent); break; } -
Handle the NODE_ON_DROP event.
In the NODE_ON_DROP event, perform operations related to the drop phase, typically involving retrieving the data passed during the drag process. For example, import the udmf_meta.h file, obtain OH_UdmfData, check whether the required data type exists, extract the corresponding data from OH_UdmfRecord, and destroy the pointer.
void GetDragData(ArkUI_DragEvent* dragEvent) { // Obtain the UDMF data. int returnValue; // Create an OH_UdmfData object. OH_UdmfData *data = OH_UdmfData_Create(); returnValue = OH_ArkUI_DragEvent_GetUdmfData(dragEvent, data); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragEvent_GetUdmfData returnValue = %{public}d", returnValue); // Check whether OH_UdmfData has the required data type. bool resultUdmf = OH_UdmfData_HasType(data, UDMF_META_GENERAL_FILE); if (resultUdmf) { // Obtain records from OH_UdmfData. unsigned int recordsCount = 0; OH_UdmfRecord **records = OH_UdmfData_GetRecords(data, &recordsCount); // Extract elements from records. int returnStatus; for (int i = 0; i < recordsCount; i++) { // Obtain the file type data from OH_UdmfRecord. OH_UdsFileUri *imageValue = OH_UdsFileUri_Create(); returnStatus = OH_UdmfRecord_GetFileUri(records[i], imageValue); const char *fileUri = OH_UdsFileUri_GetFileUri(imageValue); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "dragTest OH_UdmfRecord_GetPlainText " "returnStatus= %{public}d " "fileUri= %{public}s", returnStatus, fileUri); // Destroy the pointer after use. OH_UdsFileUri_Destroy(imageValue); } if (recordsCount != 0) { OH_ArkUI_DragEvent_SetDragResult(dragEvent, ARKUI_DRAG_RESULT_SUCCESSFUL); ArkUI_DropOperation option; OH_ArkUI_DragEvent_GetDropOperation(dragEvent, &option); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragEvent_GetDropOperation returnValue = %{public}d", option); } } else { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_UdmfData_HasType not contain UDMF_META_GENERAL_FILE"); } int32_t count; OH_ArkUI_DragEvent_GetDataTypeCount(dragEvent, &count); if (count <= 0 || count >= 128U) { return; } char **eventTypeArray = new char *[count]; for (int i = 0; i < count; i++) { eventTypeArray[i] = new char[128U]; } OH_ArkUI_DragEvent_GetDataTypes(dragEvent, eventTypeArray, count, 128U); for (int i = 0; i < count; i++) { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragEvent_GetDataTypes returnValue = %{public}s", eventTypeArray[i]); } } // ... case NODE_ON_DROP: { OH_ArkUI_DragEvent_SetSuggestedDropOperation(dragEvent, ARKUI_DROP_OPERATION_COPY); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DROP EventReceiver"); GetDragData(dragEvent); break; }
Initiating a Drag Operation
In addition to the basic drag-and-drop functionality, ArkUI allows you to initiate a drag operation using C APIs. The following example demonstrates how to use C APIs to start a drag operation with text data and highlights key points to keep in mind during development.
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Register node events.
Create a Button node, set its attributes, and register the NODE_ON_TOUCH_INTERCEPT event.
// Use buttonTouch as targetId to distinguish events from different targets. enum { BUTTON_TOUCH = 1 }; dragButton = nodeAPI->createNode(ARKUI_NODE_BUTTON); SetId(dragButton, "dragBt3"); SetCommonAttribute(dragButton, 80.0f, 50.0f, 0xFFFF0000, 20.0f); SetButtonLabel(dragButton, "Drag"); nodeAPI->registerNodeEvent(dragButton, NODE_ON_TOUCH_INTERCEPT, BUTTON_TOUCH, nullptr);#define DEFAULT_WIDTH 200.0 // Set the node brightness. void SetWidth(ArkUI_NodeHandle &node, float width = DEFAULT_WIDTH) { if (!nodeAPI) { return; } ArkUI_NumberValue widthValue[] = {width}; ArkUI_AttributeItem widthItem = {widthValue, 1}; nodeAPI->setAttribute(node, NODE_WIDTH, &widthItem); } #define DEFAULT_HEIGHT 200.0 // Set the node height. void SetHeight(ArkUI_NodeHandle &node, float height = DEFAULT_HEIGHT) { if (!nodeAPI) { return; } ArkUI_NumberValue heightValue[] = {height}; ArkUI_AttributeItem heightItem = {heightValue, 1}; nodeAPI->setAttribute(node, NODE_HEIGHT, &heightItem); } #define DEFAULT_BG_COLOR 0xFFFFFFFF // Set the background color of the node. void SetBackgroundColor(ArkUI_NodeHandle &node, uint32_t color = DEFAULT_BG_COLOR) { if (!nodeAPI) { return; } ArkUI_NumberValue colorValue[] = {{.u32 = color}}; ArkUI_AttributeItem colorItem = {colorValue, 1}; nodeAPI->setAttribute(node, NODE_BACKGROUND_COLOR, &colorItem); } #define DEFAULT_MARGIN 5.0 // Set the margin of the node. void SetMargin(ArkUI_NodeHandle &node, float margin = DEFAULT_MARGIN) { if (!nodeAPI) { return; } ArkUI_NumberValue marginValue[] = {margin}; ArkUI_AttributeItem marginItem = {marginValue, 1}; nodeAPI->setAttribute(node, NODE_MARGIN, &marginItem); } // Set tags for a Button node. void SetButtonLabel(ArkUI_NodeHandle &node, const char *label) { if (!nodeAPI) { return; } ArkUI_AttributeItem NODE_Button_SRC_Item = {.string = label}; nodeAPI->setAttribute(node, NODE_BUTTON_LABEL, &NODE_Button_SRC_Item); } // Set the node identifier. void SetId(ArkUI_NodeHandle &node, const char *id) { if (!nodeAPI) { return; } ArkUI_AttributeItem idItem = {.string = id}; nodeAPI->setAttribute(node, NODE_ID, &idItem); } #define DEFAULT_BORDER_WIDTH 0.0 // Set the border width for the node. void SetBorderWidth(ArkUI_NodeHandle &node, float width = DEFAULT_BORDER_WIDTH) { if (!nodeAPI) { return; } ArkUI_NumberValue borderWidthValue[] = {width}; ArkUI_AttributeItem borderWidthItem = {borderWidthValue, 1}; nodeAPI->setAttribute(node, NODE_BORDER_WIDTH, &borderWidthItem); } #define DEFAULT_BORDER_COLOR 0xFF000000 // Set the border color of the node. void SetBorderColor(ArkUI_NodeHandle &node, uint32_t color = DEFAULT_BORDER_COLOR) { if (!nodeAPI) { return; } ArkUI_NumberValue borderColorValue[] = {{.u32 = color}}; ArkUI_AttributeItem borderColorItem = {borderColorValue, 1}; nodeAPI->setAttribute(node, NODE_BORDER_COLOR, &borderColorItem); } // Set common node attributes, such as the width, height, background color, margin, and border style. void SetCommonAttribute(ArkUI_NodeHandle &node, float width = DEFAULT_WIDTH, float height = DEFAULT_HEIGHT, unsigned int color = DEFAULT_BG_COLOR, float margin = DEFAULT_MARGIN) { SetWidth(node, width); SetHeight(node, height); SetBackgroundColor(node, color); SetMargin(node, margin); SetBorderWidth(node, DEFAULT_BORDER_WIDTH); SetBorderColor(node); } -
Receive the NODE_ON_TOUCH_INTERCEPT event.
In the NODE_ON_TOUCH_INTERCEPT event, you need to set up DragAction to initiate the drag operation. Use targetId to distinguish events triggered by different buttons.
nodeAPI->addNodeEventReceiver(dragButton, [](ArkUI_NodeEvent *event) { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "RegisterNodeEventForthReceiver called"); auto eventType = OH_ArkUI_NodeEvent_GetEventType(event); auto preDragStatus = OH_ArkUI_NodeEvent_GetPreDragStatus(event); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "eventType = %{public}d, preDragStatus = %{public}d", eventType, preDragStatus); auto *dragEvent = OH_ArkUI_NodeEvent_GetDragEvent(event); switch (eventType) { case NODE_ON_TOUCH_INTERCEPT: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_TOUCH_INTERCEPT EventReceiver"); // ... break; } default: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "UNKNOWN EventReceiver"); break; } } }); -
Set the drag action.
In the NODE_ON_TOUCH_INTERCEPT event, set DragAction to initiate the drag operation. Create a PixelMap, set ArkUI_DragPreviewOption and the touch point, and set the text data to DragAction.
case NODE_ON_TOUCH_INTERCEPT: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_TOUCH_INTERCEPT EventReceiver"); // Create a DragAction object. action = OH_ArkUI_CreateDragActionWithNode(dragButton); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_CreateDragActionWithNode returnValue = %{public}p", action); // Set a PixelMap object. std::vector<OH_PixelmapNative *> pixelVector; SetPixelMap(pixelVector); // Set DragPreviewOption. SetDragPreviewOption(); // Set pointerId and touchPoint. PrintDragActionInfos(); // Set unifiedData. SetDragActionData(); // startDrag int returnValue = OH_ArkUI_StartDrag(action); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_StartDrag returnValue = %{public}d", returnValue); OH_ArkUI_DragAction_Dispose(action); break; } // ... void SetDragActionData() { // Create an OH_UdmfRecord object. OH_UdmfRecord *record = OH_UdmfRecord_Create(); // Add plain text data to OH_UdmfRecord. OH_UdsPlainText *plainText = OH_UdsPlainText_Create(); int returnStatus; OH_UdsPlainText_SetAbstract(plainText, "this is plainText Abstract example"); OH_UdsPlainText_SetContent(plainText, "this is plainText Content example"); returnStatus = OH_UdmfRecord_AddPlainText(record, plainText); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "dragTest OH_UdmfRecord_AddPlainText returnStatus = %{public}d", returnStatus); // Create an OH_UdmfData object. OH_UdmfData *data = OH_UdmfData_Create(); // Add OH_UdmfRecord to OH_UdmfData. returnStatus = OH_UdmfData_AddRecord(data, record); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "dragTest OH_UdmfData_AddRecord returnStatus = %{public}d", returnStatus); int returnValue = OH_ArkUI_DragAction_SetData(action, data); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragAction_SetData returnValue = %{public}d", returnValue); // Register a drag status listener. OH_ArkUI_DragAction_RegisterStatusListener(action, data, &DragStatusListener); }void SetPixelMap(std::vector<OH_PixelmapNative *> &pixelVector) { uint8_t data[960000]; size_t dataSize = 960000; for (int i = 0; i < dataSize; i++) { data[i] = i + 1; } // Create a parameter structure instance and set parameters. OH_Pixelmap_InitializationOptions *createOpts; OH_PixelmapInitializationOptions_Create(&createOpts); OH_PixelmapInitializationOptions_SetWidth(createOpts, 200U); OH_PixelmapInitializationOptions_SetHeight(createOpts, 300U); OH_PixelmapInitializationOptions_SetPixelFormat(createOpts, PIXEL_FORMAT_BGRA_8888); OH_PixelmapInitializationOptions_SetAlphaType(createOpts, PIXELMAP_ALPHA_TYPE_UNKNOWN); // Create a Pixelmap instance. OH_PixelmapNative *pixelmap = nullptr; OH_PixelmapNative_CreatePixelmap(data, dataSize, createOpts, &pixelmap); OH_PixelmapNative_Flip(pixelmap, true, true); pixelVector.push_back(pixelmap); int returnValue = OH_ArkUI_DragAction_SetPixelMaps(action, pixelVector.data(), pixelVector.size()); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragAction_SetPixelMaps returnValue = %{public}d", returnValue); } void SetDragPreviewOption() { auto *previewOptions = OH_ArkUI_CreateDragPreviewOption(); OH_ArkUI_DragPreviewOption_SetScaleMode(previewOptions, ArkUI_DragPreviewScaleMode::ARKUI_DRAG_PREVIEW_SCALE_DISABLED); OH_ArkUI_DragPreviewOption_SetDefaultShadowEnabled(previewOptions, true); OH_ArkUI_DragPreviewOption_SetDefaultRadiusEnabled(previewOptions, true); int returnValue = OH_ArkUI_DragAction_SetDragPreviewOption(action, previewOptions); OH_ArkUI_DragPreviewOption_Dispose(previewOptions); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragAction_SetDragPreviewOption returnValue = %{public}d", returnValue); } void PrintDragActionInfos() { // Set pointerId. int returnValue = OH_ArkUI_DragAction_SetPointerId(action, 0); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragAction_SetPointerId returnValue = %{public}d", returnValue); // Set the touch point. returnValue = OH_ArkUI_DragAction_SetTouchPointX(action, 200.0f); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragAction_SetTouchPointX returnValue = %{public}d", returnValue); returnValue = OH_ArkUI_DragAction_SetTouchPointY(action, 200.0f); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragAction_SetTouchPointY returnValue = %{public}d", returnValue); } -
Handle the NODE_ON_DROP event.
In the NODE_ON_DROP event, perform actions related to the drop phase. Typically, this involves obtaining the data passed during the drag operation. The drag data from DragAction is also obtained through DragEvent
case NODE_ON_DROP: { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "NODE_ON_DROP EventReceiver"); GetUdmfDataText(dragEvent); OH_ArkUI_DragAction_UnregisterStatusListener(action); break; } // ... void GetUdmfDataText(ArkUI_DragEvent* dragEvent) { // Obtain the UDMF data. int returnValue; // Create an OH_UdmfData object. OH_UdmfData *data = OH_UdmfData_Create(); returnValue = OH_ArkUI_DragEvent_GetUdmfData(dragEvent, data); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_ArkUI_DragEvent_GetUdmfData returnValue = %{public}d", returnValue); // Check whether OH_UdmfData has the required data type. bool resultUdmf = OH_UdmfData_HasType(data, UDMF_META_PLAIN_TEXT); if (resultUdmf) { // Obtain records from OH_UdmfData. unsigned int recordsCount = 0; OH_UdmfRecord **records = OH_UdmfData_GetRecords(data, &recordsCount); // Extract elements from records. int returnStatus; for (int i = 0; i < recordsCount; i++) { // Obtain plain text data from OH_UdmfRecord. OH_UdsPlainText *plainTextValue = OH_UdsPlainText_Create(); returnStatus = OH_UdmfRecord_GetPlainText(records[i], plainTextValue); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "dragTest OH_UdmfRecord_GetPlainText " "returnStatus= %{public}d", returnStatus); auto getAbstract = OH_UdsPlainText_GetAbstract(plainTextValue); auto getContent = OH_UdsPlainText_GetContent(plainTextValue); OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_UdsPlainText_GetAbstract = " "%{public}s, OH_UdsPlainText_GetContent = " "%{public}s", getAbstract, getContent); // Destroy the pointer after use. OH_UdsPlainText_Destroy(plainTextValue); } } else { OH_LOG_Print(LOG_APP, LOG_INFO, 0xFF00U, "dragTest", "OH_UdmfData_HasType not contain UDMF_META_PLAIN_TEXT"); } OH_UdmfData_Destroy(data); }