android项目从零开始 Android webview支持 文件上传、图片上传

项目中用webview包裹网站，出现上传文件无反应的情况，之前了解过文件上传。现在的前端页面需要处理的是

1.打开本地文件选择器

2.用户选择需要上传的文件

3.处理用户选择的文件通知webview

4.前端提交表单上传文件

首先需要webview 对 JS 的支持

webview.getSettings().setJavaScriptEnable(true)

前端页面针对不同版本的android系统 webview内核会有不同，调用方法不一致

webview.setWebChromeClient(new WebChromeClient() {

// For Android < 3.0
public void openFileChooser(ValueCallback<Uri> valueCallback) {
***
}

// For Android  >= 3.0
public void openFileChooser(ValueCallback valueCallback, String acceptType) {
***
}

//For Android  >= 4.1
public void openFileChooser(ValueCallback<Uri> valueCallback,
String acceptType, String capture) {
***
}

// For Android >= 5.0
@Override
public boolean onShowFileChooser(WebView webView,
ValueCallback<Uri[]> filePathCallback,
WebChromeClient.FileChooserParams fileChooserParams) {
***
return true;
}
});

完整代码

public class MainActivity extends AppCompatActivity {

private ValueCallback<Uri> uploadMessage;
private ValueCallback<Uri[]> uploadMessageAboveL;
private final static int FILE_CHOOSER_RESULT_CODE = 10000;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

WebView webview = (WebView) findViewById(R.id.web_view);
assert webview != null;
WebSettings settings = webview.getSettings();
settings.setUseWideViewPort(true);
settings.setLoadWithOverviewMode(true);
settings.setJavaScriptEnabled(true);
webview.setWebChromeClient(new WebChromeClient() {

// For Android < 3.0
public void openFileChooser(ValueCallback<Uri> valueCallback) {
uploadMessage = valueCallback;
openImageChooserActivity();
}

// For Android  >= 3.0
public void openFileChooser(ValueCallback valueCallback, String acceptType) {
uploadMessage = valueCallback;
openImageChooserActivity();
}

//For Android  >= 4.1
public void openFileChooser(ValueCallback<Uri> valueCallback, String acceptType, String capture) {
uploadMessage = valueCallback;
openImageChooserActivity();
}

// For Android >= 5.0
@Override
public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
uploadMessageAboveL = filePathCallback;
openImageChooserActivity();
return true;
}
});
String targetUrl = "file:///android_asset/up.html";
webview.loadUrl(targetUrl);
}

private void openImageChooserActivity() {
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("image/*");
startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILE_CHOOSER_RESULT_CODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == FILE_CHOOSER_RESULT_CODE) {
if (null == uploadMessage && null == uploadMessageAboveL) return;
Uri result = data == null || resultCode != RESULT_OK ? null : data.getData();
if (uploadMessageAboveL != null) {
onActivityResultAboveL(requestCode, resultCode, data);
} else if (uploadMessage != null) {
uploadMessage.onReceiveValue(result);
uploadMessage = null;
}
}
}

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void onActivityResultAboveL(int requestCode, int resultCode, Intent intent) {
if (requestCode != FILE_CHOOSER_RESULT_CODE || uploadMessageAboveL == null)
return;
Uri[] results = null;
if (resultCode == Activity.RESULT_OK) {
if (intent != null) {
String dataString = intent.getDataString();
ClipData clipData = intent.getClipData();
if (clipData != null) {
results = new Uri[clipData.getItemCount()];
for (int i = 0; i < clipData.getItemCount(); i++) {
ClipData.Item item = clipData.getItemAt(i);
results[i] = item.getUri();
}
}
if (dataString != null)
results = new Uri[]{Uri.parse(dataString)};
}
}
uploadMessageAboveL.onReceiveValue(results);
uploadMessageAboveL = null;
}
}