This document describes how to quickly set up a development environment \(using the Hi3516D V300 development board\) and develop a clock app running on OpenHarmony. You can click [here](https://gitee.com/openharmony/app_samples/tree/master/common/Clock) to obtain the sample code.
This document describes how to quickly set up a development environment \(using the Hi3516D V300 development board\) and develop a clock app running on OpenHarmony. You can click [here](https://gitee.com/openharmony/app_samples/tree/master/common/Clock) to obtain the sample code.
The clock app displays the current time, as shown in the following figure.
Download and install DevEco Studio. For details, see the [HUAWEI DevEco Studio User Guide](../../application-dev/quick-start/deveco-studio-user-guide-for-openharmony.md).
Download and install DevEco Studio. For details, see the [HUAWEI DevEco Studio User Guide](../../application-dev/quick-start/deveco-studio-user-guide-for-openharmony.md).
## How to Develop<a name="section19901741111312"></a>
The Clock app displays the current time through a clock face and numbers.
The clock app displays the current time through a clock face and numbers.
As shown in [Figure 1 Clock display effect](#fig7763172132019), the UI consists of two parts:
As shown in [Figure 1](#fig7763172132019), the UI consists of two parts:
- Clock face area: displays a dynamic analog clock whose hands rotate accurately.
- Digital time area: displays the current time in numerals.
To build such an app, we can create a page that has a flexible layout with two rows vertically arranged. The development procedure is as follows:
1. Add a root component **<div\>** to the **.hml** file. Note that each **.hml** file can contain only one root component. The sample code is as follows:
1.Add a root component **<div\>** to the **.hml** file. Note that each **.hml** file can contain only one root component. The sample code is as follows:
```
<div class="container">
</div>
```
**class="container"** indicates the style used by the component. The **container** is a style class defined in the **index.css** file.
**class="container"** indicates the style used by the component. The **container** is a style class defined in the **index.css** file.
```
.container {
...
...
@@ -45,9 +45,9 @@ To build such an app, we can create a page that has a flexible layout with two r
}
```
The height and width of the root component **<div\>** are set in the style class. Note that the height and width must be explicitly specified \(except for some components, such as **<text\>**\). Otherwise, the component may fail to display. In the **container** style class, the **flex-direction** attribute is set to **column**, which means that child components of **<div\>** are vertically arranged from top to bottom for implementing the flexible page layout.
The height and width of the root component **<div\>** are set in the style class. Note that the height and width must be explicitly specified \(except for some components, such as **<text\>**\). Otherwise, the component may fail to display. In the **container** style class, the **flex-direction** attribute is set to **column**, which means that child components of **<div\>** are vertically arranged from top to bottom for implementing the flexible page layout.
2. Implement clock hand rotation using the **<stack\>** component. The **<stack\>** component provides a stack container where child components are successively stacked and the latter one overwrites the previous one.
2.Implement clock hand rotation using the **<stack\>** component. The **<stack\>** component provides a stack container where child components are successively stacked and the latter one overwrites the previous one.
Add a stack container to the root component. The sample code is as follows:
...
...
@@ -56,7 +56,7 @@ To build such an app, we can create a page that has a flexible layout with two r
<stack class="stack">
<image src="/common/clock_bg.png" class="clock-bg"></image> <!--Set the clock face image.-->
style="transform : rotate({{ hour * 30 + minute / 2 }}deg);"></image> <!--Set the hour hand image. (hour * 30) indicates that the hour hand rotates 30 degrees every hour. (minute / 2) indicates the rotation degrees per minute.-->
style="transform : rotate({{ hour * 30 + minute / 2 }}deg);"></image> <!--Set the hour hand image. (hour * 30) indicates that the hour hand rotates 30 degrees every hour. (minute / 2) indicates the rotation degrees per minute.-->
style="transform : rotate({{ minute * 6 + second / 10 }}deg);"></image> <!--Set the minute hand image. (minute * 6) indicates that the minute hand rotates 6 degrees every minute. (second / 10) indicates the rotation degrees per second.-->
@@ -65,7 +65,7 @@ To build such an app, we can create a page that has a flexible layout with two r
</div>
```
**style="transform: rotate\(\{\{ second \* 6 \}\}deg\)** sets the rotation event of a component. **transform** translates, rotates, or scales an image. **rotate** rotates an image. You can set an image to rotate around its x-axis or y-axis.
**style="transform: rotate\(\{\{ second \* 6 \}\}deg\)** sets the rotation event of a component. **transform** translates, rotates, or scales an image. **rotate** rotates an image. You can set an image to rotate around its x-axis or y-axis.
Set attributes, such as the height, width, and position, of the stack component in the CSS file. The sample code is as follows:
...
...
@@ -99,7 +99,7 @@ To build such an app, we can create a page that has a flexible layout with two r
}
```
Add a timer in the **index.js** file to update the hour, minute, and second variables in real time so that the time can be automatically updated on the app UI. The sample code is as follows:
Add a timer in the **index.js** file to update the hour, minute, and second variables in real time so that the time can be automatically updated on the app UI. The sample code is as follows:
```
export default {
...
...
@@ -132,13 +132,13 @@ To build such an app, we can create a page that has a flexible layout with two r
}
```
3.Display the current time in numerals under the analog clock. Add the text component at the end of the root layout. The following example shows the UI structure:
3. Display the current time in numerals under the analog clock. Add the text component at the end of the root layout. The following example shows the UI structure:
```
<text class="digit-clock"> {{ hour }}:{{ minute }}:{{ second }}</text>
```
class=**"digit-clock"** sets the height, width, and font size of the component. The sample code is as follows:
class=**"digit-clock"** sets the height, width, and font size of the component. The sample code is as follows:
```
.digit-clock {
...
...
@@ -150,7 +150,7 @@ To build such an app, we can create a page that has a flexible layout with two r
```
4. Set the style, animation effect, and dynamic data binding for all components. The complete sample code is as follows:
-**index.hml**
-**index.hml**
```
<div class="container">
...
...
@@ -167,7 +167,7 @@ To build such an app, we can create a page that has a flexible layout with two r
</div>
```
- **index.css**
- **index.css**
```
.container {
...
...
@@ -206,9 +206,9 @@ To build such an app, we can create a page that has a flexible layout with two r
}
```
- **index.js**
- **index.js**
A **.js** file is used to implement logic interactions of the clock app. The following **.js** file implements the function of periodically obtaining the system time.
A **.js** file is used to implement logic interactions of the clock app. The following **.js** file implements the function of periodically obtaining the system time.
```
export default {
...
...
@@ -247,33 +247,33 @@ To build such an app, we can create a page that has a flexible layout with two r
## Signing and Packaging<a name="section10601181101516"></a>
After finishing writing the app code, you need to sign and package the app before running it on a real device. For details, see [Signing and Packaging Guide](https://developer.harmonyos.com/en/docs/documentation/doc-guides/ohos-debugging-and-running-0000001263040487#section17660437768).
After finishing writing the app code, you need to sign and package the app before running it on a real device. For details, see [Signing and Packaging Guide](https://developer.harmonyos.com/en/docs/documentation/doc-guides/ohos-debugging-and-running-0000001263040487#section17660437768).
## Running on the Real Device<a name="section092721731511"></a>
Before you install the app and run it on the development board, install the DevEco Device Tool by following operations provided in [HUAWEI DevEco Device Tool User Guide](https://device.harmonyos.com/en/docs/ide/user-guides/service_introduction-0000001050166905). Burn OpenHarmony into the development board, and run it on the board. For details about how to build, burn, and run an image, see . After the image is running normally and the system is started properly, perform the following steps to install or uninstall the app:
Before you install the app and run it on the development board, install the DevEco Device Tool by following operations provided in [HUAWEI DevEco Device Tool User Guide](https://device.harmonyos.com/en/docs/ide/user-guides/service_introduction-0000001050166905). Burn OpenHarmony into the development board and run it. For details about how to build, burn, and run an image, see [Standard System Overview](../quick-start/quickstart-standard-overview.md). After the image is running normally and the system is started properly, perform the following steps to install or uninstall the app:
Change the HDC client name to **hdc.exe** and add the path above to the system environment variable **path**.
Change the HDC client name to **hdc.exe** and add the path above to the system environment variable **path**.
2. Open the **cmd** window, and run the following commands to push the HAP file to the device directory, and install it:
2.Open the **cmd** window, and run the following commands to push the HAP file to the device directory, and install it:
```
hdc install clock.hap
```
3. Run the following command to start the app. **ohos.samples.clock** indicates the app package name, and **MainAbility** indicates the ability started by the app.
3.Run the following command to start the app. **ohos.samples.clock** indicates the app package name, and **MainAbility** indicates the ability started by the app.
```
hdc shell aa start -d 123 -a ohos.samples.clock.MainAbility -b ohos.samples.clock
```
4.\(Optional\) Run the following command to uninstall the app. **ohos.samples.clock** indicates the app package name.
4.\(Optional\) Run the following command to uninstall the app. **ohos.samples.clock** indicates the app package name.
```
hdc shell bm uninstall -n ohos.samples.clock
...
...
@@ -284,33 +284,31 @@ Before you install the app and run it on the development board, install the DevE
### hdc\_std Fails to Connect to a Device<a name="section1922725151614"></a>
-**Symptom**
-**Symptom**
**\[Empty\]** is displayed in the output after the **hdc\_std list targets** command is run.
**\[Empty\]** is displayed in the output after the **hdc\_std list targets** command is run.
-**Possible Causes and Solutions**
1. The device fails to be identified.
-**Possible Causes and Solutions**
- The device fails to be identified.
Check whether **HDC Device** exists in the universal serial bus device of the device manager. If **HDC Device** does not exist, the device cannot be connected. In this case, remove and then insert the device or burn the latest image for the device.
Check whether **HDC Device** exists in the universal serial bus device of the device manager. If **HDC Device** does not exist, the device cannot be connected. In this case, remove and then insert the device or burn the latest image for the device.
2. hdc\_std works improperly.
- hdc\_std works improperly.
Run the **hdc kill** or **hdc start -r** command to kill or restart the HDC service, and then run the **hdc list targets** command to check whether device information is obtained.
Run the **hdc kill** or **hdc start -r** command to kill or restart the HDC service, and then run the **hdc list targets** command to check whether device information is obtained.
3. hdc\_std does not match the device.
- hdc\_std does not match the device.
If the latest image is burnt for the device, hdc\_std must also be of the latest version. As hdc\_std is updated continuously, obtain hdc\_std of the latest version from the **developtools\_hdc\_standard** repository in the **prebuilt** directory.
If the latest image is burnt for the device, hdc\_std must also be of the latest version. As hdc\_std is updated continuously, obtain hdc\_std of the latest version from the **developtools\_hdc\_standard** repository in the **prebuilt** directory.
### hdc\_std Fails to Run<a name="section15657547131615"></a>
-**Symptom**
-**Symptom**
The **hdc\_std.exe** file does not run after being clicked.
-**Possible Causes and Solutions**
**hdc\_std.exe** requires no installation and can be directly used on a disk. It can also be added to environment variables. Open the **cmd** window and run the **hdc\_std** command to use **hdc\_std.exe**.
The **hdc\_std.exe** file does not run after being clicked.
-**Possible Causes and Solutions**
**hdc\_std.exe** requires no installation and can be directly used on a disk. It can also be added to environment variables. Open the **cmd** window and run the **hdc\_std** command to use **hdc\_std.exe**.
@@ -10,16 +10,17 @@ Based on the Hi3861 platform, the OpenHarmony WLAN module provides abundant peri
LED control examples are stored in the file **applications/sample/wifi-iot/app/iothardware/led\_example.c**.
2. Understand the cable connections by referring to the schematic diagram. You can learn that LED of hispark pegasus is connected to pin 9 of the chip.
2. Understand the cable connections by referring to the schematic diagram of the development board. You can learn that LED of hispark pegasus is connected to pin 9 of the chip.
