关于Android进度条工作的java
我对安卓中的进度条有疑问。我还没有实施它,但由于时间不够,我想确保在实施时,我最好弄清楚将要发生什么以及为什么
dialog = new ProgressDialog(this);
dialog.setCancelable(true);
dialog.setMessage("Loading...");
// set the progress to be horizontal
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
// reset the bar to the default value of 0
dialog.setProgress(0);
// get the maximum value
EditText max = (EditText) findViewById(R.id.maximum);
// convert the text value to a integer
int maximum = Integer.parseInt(max.getText().toString());
// set the maximum value
dialog.setMax(maximum);
// display the progressbar
dialog.show();
// create a thread for updating the progress bar
Thread background = new Thread (new Runnable() {
public void run() {
try {
// enter the code to be run while displaying the progressbar.
//
// This example is just going to increment the progress bar:
// So keep running until the progress value reaches maximum value
while (dialog.getProgress()<= dialog.getMax()) {
// wait 500ms between each update
Thread.sleep(500);
// active the update handler
progressHandler.sendMessage(progressHandler.obtainMessage());
}
} catch (java.lang.InterruptedException e) {
// if something fails do something smart
}
}
});
// start the background thread
background.start();
}
// handler for the background updating
Handler progressHandler = new Handler() {
public void handleMessage(Message msg) {
dialog.incrementProgressBy(increment);
}
};
这是我从某处获取的上述代码。。。正如这段代码所说,我必须将我的实际代码保持在下面,尝试保持进度条运行。。我的疑问是,我的代码很长,包含嵌套的for循环(用所有这些位和字节解析整个文件)。。如果我将冗长的过程保留在该部分,它如何更新进度条,直到完成任务? 我是不是错过了一些概念?请解释我如何保持进程运行并更新进度条
# 1 楼答案
您应该使用AsynTask并在其
onPreExecute()
方法中显示ProgreesBar,并在其onPostExecute()
方法中关闭ProgressBar。用doInBackground()
方法加载所有内容。此外,要更新ProgressBar,请使用onProgressUpdate()
这将有助于:http://developer.android.com/reference/android/os/AsyncTask.html