runOnUiThread爆红
时间: 2024-05-16 22:17:44 浏览: 81
runOnUiThread是Android开发中常用的方法之一,它可以在UI线程中运行代码,避免了在非UI线程中执行UI操作导致的崩溃问题。
在Android中,所有UI组件都必须在UI线程中更新,否则会发生异常。而在子线程中更新UI组件时,就需要使用runOnUiThread方法来切换到UI线程中更新。
示例代码:
```
new Thread(new Runnable() {
@Override
public void run() {
// 非UI线程中执行代码
// ...
// 切换回UI线程更新UI组件
runOnUiThread(new Runnable() {
@Override
public void run() {
// UI线程中执行更新UI组件的代码
// ...
}
});
}
}).start();
```
需要注意的是,runOnUiThread方法只有在Activity或Fragment中才能使用,如果在其他的非UI组件中使用会导致崩溃。
相关问题
runOnUiThread
`runOnUiThread` 是 Android 中的一个方法,它可以让你在 UI 线程中执行一些代码,即使你在非 UI 线程中。这个方法通常用于在异步任务完成时更新 UI。在调用 `runOnUiThread` 方法时,你需要传递一个 `Runnable` 对象,这个对象包含了你想要在 UI 线程中执行的代码。
例如,如果你在一个非 UI 线程中要更新一个 TextView 的文本,你可以使用以下代码:
```
runOnUiThread(new Runnable() {
@Override
public void run() {
textView.setText("Hello, world!");
}
});
```
这个代码会将修改 TextView 文本的代码封装在一个 `Runnable` 对象中,并在 UI 线程中执行这个对象。这样就可以避免在非 UI 线程中修改 UI 导致的异常和错误。
android runonuithread
Android `runOnUiThread` is a method that allows you to execute code on the UI thread. The UI thread is also known as the main thread, and it is responsible for handling user interface events such as drawing the screen, responding to user input, and updating the view hierarchy.
When you call `runOnUiThread`, the code you provide is queued up to be executed on the UI thread. This is useful when you need to update the UI from a background thread or perform some other action that must be executed on the UI thread.
Here is an example of using `runOnUiThread` to update a TextView with some text:
```
runOnUiThread(new Runnable() {
public void run() {
TextView textView = findViewById(R.id.text_view);
textView.setText("Hello, world!");
}
});
```
In this example, we create a new `Runnable` object that contains the code we want to execute on the UI thread. We then call `runOnUiThread` and pass in this `Runnable` object.
Inside the `run` method of the `Runnable` object, we obtain a reference to a TextView and set its text to "Hello, world!". Because we are running this code on the UI thread, the text will be updated immediately and the user will see the new text on the screen.